xt te Environmental Assessment & Management Plan main Project ctric eelordyH 2 nuehTm aN March 2005 Table of Contents Table of Contents Table of Contents i List of Figures xiii List of Tables xv List of Plates xvii Acronyms xix Preface xxi Project History xxi GOL Environmental & Social Concerns xxi Involvement of the World Bank & First Environmental Assessments xxi Nam Theun Social & Environmental Project xxi Development of the EAMP xxii The Safeguard Documents xxii Organisation of the Report xxii Procedure for Questions & Answers xxiii 1. Project Background 1 Brief Description 2 Project Equity 2 Table Need & Rationale 2 Potential Contribution to the Economy of Lao PDR 3 of Lao Policy, Legal & Administrative Framework 3 Contents National Laws 3 The Environmental Protection Law, 1999 3 The Forestry Law, 1996 4 The Water Law, 1996 4 The Electricity Law, 1997 4 Additional Decrees 4 PM Decree 164 of 1993 Relative to the Establishment of National Biodiversity Conservation Areas 4 PM Decree 193 of 2000 Relative to the Definition of Boundaries of the NNT NBCA & Corridors, Reservoir & Reselement Area 4 PM Decree 25 of 2001 Relative to the Establishment of the Nam Theun 2 Watershed Management & Protection Authority 5 Other Ministerial Decisions & Orders 5 GOL Resettlement Policy 5 GOL Responsibilities Under International Treaties 5 Convention on Biological Diversity 5 Convention on Climate Change 5 Convention on the Protection of the World Cultural & Natural Heritage 6 Agreement on the Cooperation for Sustainable Development of the Mekong River Basin 6 International Waterways 6 Disputed Territories 6 Other International Conventions 6 Enforcement & Implementation of the Law Relative to the Project 6 2. Project Description & Analysis of Alternatives 7 Analysis of Alternatives 8 Market for Power Exports from Lao PDR 8 Regional Market 8 Power Generation Options in Thailand 8 Power Generation Options in Lao PDR 9 Review of Lao PDR Candidate Projects 9 Comparison of Alternative Power Projects 9 Comparison of Multi-Project Scenarios for Power Export 10 Findings of the Analysis of Alternatives 10 No Project Scenario 10 Evaluation of Alternative Configurations 11 Table of Contents i EAMP Main Text Reduction in the Size of the Reservoir 11 Reducing the Effects of Discharges into the Xe Bang Fai 11 Reducing the Impacts in the Downstream Nam Theun 13 Incorporation of Lessons Learned from Other Hydropower Projects 13 Description of Project Infrastructure 13 Nakai Dam & Reservoir 13 Nakai Dam 13 Spillway 15 Outlet Conduit for Riparian Release 15 Ancillary Structures at the Nakai Dam 15 Nakai Reservoir 15 Saddle Dams 15 Flow Diversion 16 Headrace Channel 16 Intake Structures 16 Underground Works 16 Power Station 16 Power Station & Generation Units 16 SCADA System 17 Downstream Hydraulic Control & Conveyance 17 Tailrace Channel, Regulating Pond & Regulating Dam 17 Nam Kathang Release 18 Downstream Channel 18 Substations 19 Transmission Lines 19 Mekong crossing 19 Ancillary Works 22 Roads & Bridges 22 Residence Nam Theun 22 Materials Sources 24 Spoil Disposal Areas 24 Construction Work Camps 24 Contents Project Construction, Operation & Decommissioning 24 of Construction 24 Construction Schedule 24 Construction Contracts 24 ableT Project Cost 24 Operation 25 Operation of the Nakai Dam 25 Operation of the Nakai Reservoir 25 Operation of the Power Station 25 Operation of the Regulating Pond 26 Project Decommissioning 26 Location & Study Area 26 The River Basins 26 Nam Theun Basin 26 Xe Bang Fai Basin 28 Overall Study Area 28 Zone 1: Inundation Zone 28 Zone 2: Protected Area & Corridor Areas 28 Zone 3: Proposed Resettlement Area 28 Zone 4: Nam Theun Downstream to Theun-Hinboun Headpond 29 Zone 5: Theun Hinboun Dam to Next Major Tributary 29 Zone 6: Lak Sao Road & Quarry 29 Zone 7: Power Station to Regulating Dam 29 Zone 8: Downstream Channel from Regulating Dam to Nam Phit/Xe Bang Fai Confluence 29 Zone 9: Nam Kathang 29 Zone 10: Upper Xe Bang Fai 29 Zone 11: Middle Xe Bang Fai 29 Zone 12: Lower Xe Bang Fai 29 Zone 14: Thakhek Road 29 Zone 15: Mekong River 29 Economic Analysis Environmental and Social Impacts 30 Area 1. Nam Theun downstream. 30 Area 2. Nakai - Nam Theun NPA. 30 Area 3. Nakai Reservoir. 30 Area 4. Xe Bang Fai. 32 ii Table of Contents Table of Contents Area 5: Mekong River. 32 Area 6: Project lands. 32 3. Assessment of Environmental Impacts 33 Global & Regional Issues 34 Greenhouse Gases 34 Mitigation 35 Global Biodiversity 35 Trans-basin Diversion of Water 35 Hydrologic Changes in the Nam Theun & Xe Bang Fai 35 Hydrologic Changes in the Mekong River 35 Effects to Operation of the Theun Hinboun Project 36 Effects of Diversion on the Xe Bang Fai 36 Cumulative Impact Assessment 36 Introduction and Scope 36 Cumulative Impacts of Anticipated Regional Development 38 Sectoral Environmental Assessment of the Hydropower Sector 38 Intact River Assessment 38 Regional Biodiversity 38 Topography, Geology & Soils 39 Baseline 39 Dam Site 39 Nakai Plateau 39 Geology 39 Potential Local Faults 39 Soils 39 Headrace Channel & Surge Sha 41 Tailrace, Regulating Pond & Downstream Channel 41 Table Reaches of the Xe Bang Fai 41 Potential Impacts 41 Reservoir Induced Seismicity 41 of Reservoir Water Tightness 41 Relationship Between the Reservoir & the Underlying Limestone 41 Contents Relationship between the Reservoir & Adjoining Catchments 42 Erosion & Sedimentation 42 Reservoir Area 42 Erosion Rates 42 Loss of Storage Volume 42 Proposed Mitigation & Monitoring 43 In-Stream Degradation 43 Downstream Nam Theun 43 Downstream Channel 43 Nam Kathang 43 Xe Bang Fai 43 Proposed Mitigation, Compensation & Monitoring 45 Climate 45 Baseline 45 General 45 Rainfall 46 Relative Humidity 46 Temperature 46 Wind Speed 46 Evaporation 48 Potential Impacts 48 Air & Water Temperature 48 Wet Haze & Fog 49 Precipitation Enhancement & Evaporation 50 Downslope Winds 50 Cloud Base Changes 50 Hydrology & Water Resources 50 Baseline Hydrology 50 Upper Nam Theun Basin 51 Discharge at Ban Thalang 51 Discharge at the Nakai Dam Site 51 Extreme Discharges 52 Nam Kathang 52 Discharge 52 Table of Contents iii EAMP Main Text Extreme Flows 53 Xe Bang Fai at Mahaxai 53 Discharge 53 Extreme flows 53 Mekong River 53 Long Term Trends 54 Baseline Groundwater Hydrology 54 Potential Impacts 54 Nakai Plateau 55 Nam Theun Downstream From the Dam & Nam Kading (Zones 4 & 5) 55 Regulating Pond, Downstream Channel & Gnommalat Plain 56 Hydrologic Changes in the Nam Kathang 57 Hydrologic Changes in the Xe Bang Fai 57 Upper Xe Bang Fai 57 Middle Xe Bang Fai 58 Lower Xe Bang Fai 58 Mekong River 61 Water Balance Among the Affected Rivers 61 Groundwater 61 Proposed Mitigation Measures, Enhancements & Compensation 61 Flooding 61 Water Levels 65 Enhancements 65 Riparian Release 65 The Riparian Release 66 Geographical Description 66 Sources of Baseline Data 66 Baseline 66 Demographic Baseline and Impact Zones 66 Hydrology 67 TH Spills and riparian release 67 Water Quality 67 Terrestrial 67 Contents Community Use 68 of Fisheries 68 Effort 69 Socio-economic benefits 69 ableT Other Water Uses 75 Assets 75 Impacts 75 Hydrology 75 Spills 75 Hydraulic Parameters and Wetted Perimeter 76 River Morphology 77 Colloidal Sediment Deposition 77 Sand Deposition 77 Gravel/cobbles/boulders Deposition 77 Water Quality 77 Rapids 77 Pools 78 Supersaturation 78 Terrestrial 78 Vegetation 78 Wildlife 78 Community use of Vegetation and Wildlife 78 Fisheries 78 Biodiversity and Abundance 78 Socio - Economic Analysis 79 Fisheries 79 Aquatic Products 81 Others Uses 81 Value of the Riverine Ecosystem 81 Vulnerable Groups 82 Other non-Project Impacts 82 Impacts of Other Planned Hydroelectric Projects 82 Trade-off 82 Mitigation 83 Mitigation Against Poor Water Quality 83 Biomass Reduction 83 Engineering Works 83 Mitigation against Sedimentation 83 Mitigation Against Injury From Flash Floods 83 iv Table of Contents Table of Contents Morphology 84 Adaptive Management 84 Compensation 84 Community Consultation 84 Monitoring 84 Intra-basin Coordination 85 Water Quality 85 Baseline Surface Water Quality 85 Nam Theun & Nam Kading 85 Dry Season 85 Wet Season 86 Xe Bang Fai, Nam Kathang & Nam Phit 86 Dry season 86 Wet Season 86 Baseline Groundwater Quality 87 Predicted Water Quality in the Nakai Reservoir & Impacts 87 Models & Assumptions 87 Results of Water Quality Modelling 87 Water Temperature 87 Dissolved Oxygen 88 Dissolved Oxygen in Other Regionally Relevant Reservoirs 88 Ammonia & Sulphide in the Nakai Reservoir & Other Regionally Relevant Reservoirs 88 Other Water Quality Factors 89 Experience from Other Hydro-Electricity Dams in Southeast Asia 89 Downstream Discharges 89 Aquatic Macrophytes 90 Predicted Water Quality Downstream from the Power Station & Impacts 90 Modelling & Assumptions 90 Results of Water Quality Analysis for the Nam Kathang & the Xe Bang Fai 90 Other Factors 91 Temperature 91 Table Supersaturation 91 Pesticides 91 Social Impacts of Water Quality Changes 91 of Mitigation of Potential Water Quality Impacts 96 Contents Monitoring 94 Terms of Reference for the Water Quality Monitoring & Assessment Programme 94 Aims & Objectives of the Programme 94 1. Development of the WQMAP: 94 2. Data Collection and Reporting: 94 3. Mitigation Measures and Evaluation: 94 Approach & Methodology 94 Standard Operating Procedures Manual 95 Parameters & Frequency for Surface Water 95 Parameters & Frequency for Groundwater 95 Additional Parameter Requirements 95 Pesticides & Other Synthetic Chemicals 95 Petrochemicals 95 Heavy Metals in Fish Tissue 95 Biological Monitoring 95 Surface Water Sampling Site Location 96 Groundwater Sampling Site Location 96 Outputs 96 Monthly Reports 96 Inter-Programme Cooperation 96 Reporting of Hazardous Levels 96 Water Quality Database 96 Evaluation & Monitoring 96 Aquatic Habitats & Fish Diversity 96 Fish Habitats 97 Lower Nam Theun Basin 97 Middle Nam Theun Basin 97 The Nakai Plateau 97 Headwaters of the Nam Theun Basin 98 Lower Xe Bang Fai Basin 98 Middle Xe Bang Fai Basin 98 Upper Xe Bang Fai Basin 98 Fish Diversity & Endemicity 98 Faunistic Affinities 100 Fish Populations 101 Xe Bang Fai Baseline Fisheries Resource Survey 101 Table of Contents v EAMP Main Text Migrations 102 Migration in the Nam Theun 102 Migration in the Xe Bang Fai 102 Fisheries 102 Potential Impacts on Aquatic Habitats 103 Construction Related Impacts 103 Work in the Riverbed 103 Infrastructure Construction 103 Water Pollution 104 Use of Explosives 104 Vegetation Clearing 104 Limestone Extraction in Karstic Formations 104 Operation Related Impacts 104 Reservoir Creation 104 Reservoir Water Quality 107 Water Diversion 107 Interruption of Fish Migrations & Destruction of Spawning Grounds: 108 Water Pollution 109 Potential Impacts by River Sector 109 Potential Impacts on Fisheries 110 Aquaculture Activity 110 Terrestrial Biodiversity 110 Baseline 110 Units of Biodiversity & Zoogeography 110 Primary Habitat Elements 113 Habitat Affinities of Wildlife 113 Reservoir Area 114 Nam Theun Downstream from the Nakai Dam 114 Dividing Hills 115 Resettlement Area 115 Wetlands 116 Dynamics of Habitat on the Nakai Plateau 116 Potential Impacts 117 Nakai Dam & the Downstream Nam Theun 117 Nakai Reservoir 118 Contents Regulating Pond & Downstream Channel 118 of Xe Bang Fai 119 Threatened Species 119 Baseline Conditions 119 ableT TheWhite-Winged Duck 120 The Elephant Population 120 Potential Impacts 121 Natural Habitats Accounting and Adequacy of Offsets 121 Natural Habitats of High Conservation Significance 121 Current Threats 122 Logging 122 Commercial Extraction of Wildlife & Non-Timber Forest Products 122 Unsustainable Agricultural Practice 122 On-going Land Development Activities on the Plateau 122 Project Impacts 122 Accounting for Degradation & Conversion 122 Reservoir 123 Fragmentation 123 Construction 124 Buffer Zones 125 Significance of Natural Habitats to be Degraded or Converted 125 National Level of Significance 125 Sub-National Level of Significance 125 Importance of Natural Habitat Degradation to Species 126 Inundated Areas & Wildlife Movements 127 White-winged Duck 127 Elephants 127 Creation of Habitats 127 Area to be Protected by the Project 127 Adequacy of Offsets 128 Conclusion 129 Mitigation Measures & Enhancements 130 Monitoring for Wildlife 130 Minimisation of Impacts During Construction 130 Minimisation of Impacts During Impoundment 130 Management of Key Wildlife Species 131 Management of Key Wildlife Species 131 Compensatory Forestry 132 vi Table of Contents Table of Contents Impacts Associated with Construction 132 General Impacts Generated by all Construction Activities 132 Water Quality 132 Sources & Types of Impacts 132 Mitigation 133 Air Quality 133 Source & Types of Impacts 133 Mitigation 133 Noise 133 Source & Types of Impacts 133 Mitigation 133 Impacts Associated with Specific Construction Activities 134 Construction of the Nakai Dam 134 Areas to be Cleared 134 Impacts of Clearing 134 Mitigation of Clearing 134 Diversion of Water 134 Impacts of Cofferdam & Diversion Tunnel Construction 134 Mitigation of Cofferdam Construction 134 Quarries 134 Source of Impact 134 Type of Impacts 135 Mitigation 135 Spoil Disposal Areas 135 Impacts 135 Mitigation 135 Work Camps, Work Areas & Labour Force 135 Impacts 135 Mitigation 135 Construction of the Headrace Channel & Upper Tunnel 135 Impacts 135 Mitigation 136 Construction of the Power Station, Lower Portion of Tunnel & Substations 136 Table Impacts 136 Mitigation 136 Construction of the Downstream Channel 136 of Impacts 136 Contents Mitigation 136 Spoil Disposal Sites 136 Other Impacts Associated with Construction Activities & Project Developments 137 Initial Filling of the Reservoir 137 Filing Sequence 137 Impacts 137 Mitigation 137 Roadways 138 Description of Roadworks 138 Design & Construction Requirements 138 Environment Crossed by the Road Works 138 Potential Impacts 139 Mitigation 140 Transmission Lines 140 Existing Environment 144 Potential Environmental Impacts: 144 Mitigation & Monitoring 147 Resettlement Sites 147 Description 147 Existing Environment 148 Potential Environmental Impacts 149 Mitigation & Monitoring 150 Physical Cultural Resources 150 Surveys and Studies 150 Baseline 150 Prehistoric Sites 151 Historic Sites 151 Spirit Sites 153 Religious Sites 153 Cemeteries 153 Other Cultural Sites 153 Palaeontologic Sites 153 Impacts 153 Construction 153 Operation 153 Mitigation and Management 153 PCR Plan 153 Pest Management Plan 155 Table of Contents vii EAMP Main Text Agriculture 155 Baseline 155 Impacts 155 Mitigation 155 Public Health 156 Baseline 156 Impacts 157 Mitigation 157 Construction 157 Baseline 157 Impacts 157 Mitigation 157 4. Assessment of Social Issues 159 Nakai ­ Nam Theun NBCA 160 Baseline 160 People & Population 160 Livelihoods & Income 160 Infrastructure 160 Education 160 Public Health 160 Impacts 160 Mitigation & Management 160 Livelihood Options & Community Development 160 Activity Framework 161 Forest & Land Use Planning, Allocation & Management 161 Participatory Protected Area Management 161 Livelihood Development for Conservation 161 Nakai Plateau & Downstream of the Nakai Dam 161 Baseline 161 People & Population 161 Livelihoods & Income 161 Agricultural Production 161 Contents Fish 161 Livestock & Poultry 162 of Non-Timber Forest Products 162 Income 162 Infrastructure 162 ableT Education 162 Public Health 162 Nam Theun Downstream of the Nakai Dam 163 Impacts 163 Nakai Plateau 163 Nam Theun Below the Nakai Dam 163 Mitigation & Management 163 Reduction of Resettlement 163 Resettlement Action Plan 164 Reselement Sites 164 Infrastructure 164 Livelihood Options 164 Pilot Village 165 Reselers Health Plan 165 Downstream of the Nakai Dam 165 Xe Bang Fai 165 Baseline 165 People & Population 165 Livelihoods 165 Agricultural Production 165 Livestock & Animal Husbandry 166 Fisheries & Aquaculture 166 Income 166 Infrastructure 166 Education 166 Public Health 166 Infectious Diseases 166 Reproductive Health 166 Nutritional Status 166 Impacts 167 Domestic Water Supply 167 Fisheries 167 Erosion 167 viii Table of Contents Table of Contents Riverbank Gardens 167 Access 167 Construction Workers 167 Mitigation, Management & Monitoring 167 Xe Bang Fai Strategy 167 Domestic Water Supply 167 Fisheries 167 Erosion 167 Riverbank Gardens 168 Access 168 Regional Health Programme 168 Nam Kathang 168 Baseline 168 Impacts 168 Mitigation 168 Project Lands 168 Baseline 168 Impacts 168 Mitigation & Management 168 Monitoring 169 Internal Monitoring 169 External Monitoring 169 Grievance Procedure 169 Enhancement of Capacity 169 5. Public Consultation & Disclosure 171 World Bank & World Commission on Dams Policies 172 The Stakeholders 172 Table Public Consultation & Disclosure Process 172 Three Phase Process 172 of Phase 1: Information Collection & Dissemination 172 Contents Phase 2: Consultation with Stakeholders 172 Phase 3: Active Involvement in Project Design & Implementation 172 Methodology 173 The Approach 173 Use of Suitable Techniques 173 Language Issues 173 Gender Issues 175 Consultation & Participation Activities 175 Media Relations 175 Summary of PCD Activities from July 2002 - March 2005 175 Symposium "Nam Theun 2 ­ Window to the Future" 176 Site Visits 176 Follow-up Actions 176 The PCD Process Since the Advanced Draft of the EAMP to Apprasial 177 Main Stages of Information Dissemination, Consultation & Disclosure 177 Main Stakeholders in Future Consultation & Disclosure 177 Information Dissemination to the General Public 177 Information Centres 178 Mass Media 178 Translation 178 Local Consultation Events 178 Consultations & Disclosure for Nakai Plateau Resettlers 178 Consultations & Disclosure for Xe Bang Fai Riparian Villages 178 PAP Consultations & Disclosure: Project Lands 178 International Stakeholder Workshops 178 Public Disclosure 180 Environmental Assessment & Management Plan 180 Alternatives & Economic Impact Studies 180 Public Availability of Reports 180 Public Disclosure on Project Approval 180 Stakeholder Input into Project Design 180 Issues Raised by Independent Reviewers & Project Responses 180 Influence of Consultations on Project Planning 180 Table of Contents ix EAMP Main Text Influence of Consultations on Resettlement Issues 182 Influence of Consultations of the PCD Process 182 Institutional Arrangements for PCD Process 182 6. Environmental Management Plan 185 Key Organisations in the Environmental Management of the Project 186 NTPC Environmental Management Office 186 The Head Contractor 186 The HCC Environmental Management and Monitoring Plan 187 HC Monitoring and Auditing 187 GOL Organisations 188 National Environmental Committee 189 The Science, Technology & Environment Agency 189 The Environmental Management Unit 189 Overall organisation 191 Environmental management tasks outside of the Watershed 191 Responsibilities and key tasks 191 Staffing arrangements and location of offices 191 The Watershed Management & Protection Authority 191 Management of Impacts 192 Mitigation Measures to be implemented by NTPC 192 Water Quality Monitory & Assessment Programme 192 Riparian Release to Downstream of the Nam Theun 192 Aeration of Water in the Downstream Channel and the Nam Kathang 192 Downstream Channel In-Stream Degradation 192 Protecting Downstream Channel Fisheries 192 Prevention of Increased Flooding at Mahaxai 193 Degradation of the Xe Bang Fai River Channel 193 Wildlife Management and Protection Programme 193 1 - Fish impacts in upstream and downstream rivers 193 2 - Terrestrial animals in the inundation area 193 3 - Asian Elephant programme 194 Contents 4 ­ Development of a transitional strategy for reservoir impoundment. 194 5 ­ Wetland conversion and formation. 194 of Funding Support for the Implementing Agencies in the Pre-Operating Phase 194 A: EMU Technical Assistance Programme 194 B: Contribution to EMU Operational Budget 195 ableT C: EMU Capacity Building at the Local Level 195 D: EMU Training 195 Control of Synthetic Chemical Use for Pest Management & Other Purposes 195 Compensatory Forestry Programme 195 Mitigation Measures to be Implemented by the Head Contractor 195 Erosion and Sediment Control 195 Spoil Disposal 195 Quarries 198 Water Quality Monitoring (HC) 198 Chemical Waste & Control of Spills 198 Emergency Plan for Hazardous Materials 198 Air Quality 198 Noise Management 198 Physical Cultural Resources 198 Vegetation Clearing (HC) 199 Waste Management 199 Environmental Training 199 Traffic and Access 199 Explosive Ordnance Survey and Disposal 199 Construction Work Camps 199 Project Staff Health Programme 200 Transmission Lines 200 Roads 200 Mitigation Measures to be Implemented by GOL Organisations 200 Water Quality Improvements by Reduction of Biomass in the Nakai Reservoir Area 200 Control & Enforcement ­ Access & Hunting 200 Public Education Concerning Environmental Issues 200 Minimisation of environmental impacts at resettlement sites 200 Restriction of Shifting Cultivation 200 Transmission Lines 201 Implementation of Mitigation Measures 201 Provisions of the Concession Agreement 201 x Table of Contents Table of Contents Funding & Responsibilities for Implementing the Environmental Management Plan 201 Contingencies 201 Limited by Cost Objectives 201 Limited by Scope Objectives 202 Non-compliance Procedures 202 Unanticipated Project Impacts 202 Monitoring 202 Internal Monitoring by the EMO 202 Internal monitoring by the EMU 204 Independent Monitoring 204 Panel of Experts 204 Environmental grievance procedures 204 Adaptive Management 204 Adaptive Management Approach 205 Wildlife Programme: 205 Riparian Release Downstream of Nam Theun: 205 Water Release in Nam Kathang 206 Management of Release from Regulating Pond (to Downstream Channel). 206 7. Conclusion 210 Project Environment, Impacts & Mitigation 210 Social Environment, Impacts & Mitigation 210 Benefits & Rationale 211 Table of Contents Table of Contents xi EAMP Main Text Contents of ableT xii Table of Contents Table of Contents List of Figures Figure 1.1: Location of the proposed Nam Theun 2 Hydroelectric Project 2 Figure 1.2: Parties to the Project 3 Figure 2.1: Past and projected electricity demand within the Greater Mekong Sub-Region 8 Figure 2.2: Comparison of key parameters for selected Nam Theun 2 alternatives 10 Figure 2.3: Nam Theun 2 Project schematic diagram 11 Figure 2.4: Dam and spillway cross-section 13 Figure 2.5: Dam and spillway site 13 Figure 2.6: Principle Project features 14 Figure 2.7: Underground works 15 Figure 2.8: Cross-section through the Power Station 15 Figure 2.9: Regulating Dam 16 Figure 2.10: Downstream channel 17 Figure 2.11: Nam Gnom siphon 18 Figure 2.12: Confluence with Xe Bang Fai 18 Figure 2.13: Aeration weir 18 Figure 2.14: 115 kV Transmission Line schematic 19 Figure 2.15: Ban Itak crossing 19 Figure 2.16: Road construction and improvements 20 Figure 2.17: Location of quarries and spoil disposal areas 21 Figure 2.18: Location of construction work camps and work areas 23 Figure 2.19: Nakai Reservoir operation simulation 24 Figure 2.20: Regulating Pond volume (million m3) for a 50% secondary energy production scenario 25 Figure 2.21: Discharge (m3/s) from the Power Station & Regulating Dam for a 50% secondary energy production scenario 25 Table Figure 2.22: Nam Theun 2 catchment area & Xe Bang Fai basin 26 Figure 2.23: Location & study area 27 Figure 3.1: Comparison of cumulated greenhouse gas emissions 34 of Figure 3.2: NBCAs and corridor areas 35 Contents Figure 3.3: Regional geology 40 Figure 3.4: Location of cross-sectional survey sites on the Xe Bang Fai (water level recorded December 2002) 44 Figure 3.5: Recorded Ban Thalang rainfall data 46 Figure 3.6: Location of meteorological stations in the Nam Theun & Xe Bang Fai regions and seasonal rainfall variability 47 Figure 3.7: Average relative humidity 48 Figure 3.8: Seasonal temperature variability 49 Figure 3.9: Average Class A pan evaporation 49 Figure 3.10: Relative difference between air and water temperature 50 Figure 3.11: General ciculation model 50 Figure 3.12: Map of catchment areas 51 Figure 3.13: Average discharge at Ban Thalang 51 Figure 3.14: Recorded and extended monthly flows for Ban Thalang 51 Figure 3.15: Mean monthly discharge at the Nakai Dam (extended series) 52 Figure 3.16: Annual flow volumes at the Nakai Dam site 52 Figure 3.17: Monthly discharges in the Nam Kathang at the regulating dam 53 Figure 3.18: Mean, minimum and maximum discharges of the Xe Bang Fai at Mahaxai 53 Figure 3.19: Discharge in the Mekong at Nakhon Phanom 54 Figure 3.20: Discharge in the Mekong at Mukdahan 54 Figure 3.21: Nakai reservoir levels 55 Figure 3.22: Monthly discharge in the Nam Phao (only mean values available from June ­ September) 56 Figure 3.23: Regulating Pond inflow and discharge when generating 50% secondary energy 56 Figure 3.24: Discharge rate of Regulating Pond for different secondary energy levels. 57 Figure 3.25: Water height in the Xe Bang Fai (Mahaxai) Pre & Post Nam Theun 2. 58 Figure 3.26: Maximum flood depths in the lower Xe Bang Fai for the 2.6 year ARI Even in Mahaxai (pre-Project) 59 Figure 3.27: Impact of Powerhouse Discharge of 315 cumecs on Flood Extents in Lower Xe Bang Fai for 2.6yr ARI event in Mahaxai 60 Figure 3.28: Water Balance monitoring points, showing pre-NT2 operation flow levels and predicted NT2 Power Station discharge 62 Figure 3.29: Water Balance modelling pre- (Top) & post- (Bottom) NT2 operation total yearly flow 63 Figure 3.30: Water Balance modelling pre- (Top) & post- (Bottom) NT2 operation mean yearly flow 63 Figure 3.31: Water Balance modelling pre- (Top) & post- (Bottom) NT2 operation dry season (April) monthly flow 64 Figure 3.32: Water Balance modelling pre- (Top) & post- (Bottom) NT2 operation wet season (August) monthly flow 64 Figure 3.33: Zones of the Nam Theun / Nam Kading and sites of surveyed sections 67 Figure 3.34: Villages surveyed for riparian study 69 Figure 3.35: Distribution of fishing effort Ban Oudom 70 Figure 3.36: Annual fisheries production in Ban Oudom 70 Figure 3.37: Mean annual fisheries production Ban Oudom 71 Table of Contents xiii EAMP Main Text Figure 3.38: Proportion of catch utilised for HH subsistance 73 Figure 3.39: Distribution of spawning activity - Nam Theun and tributaries 75 Figure 3.40: Distribution of fish species in monthly catches 76 Figure 3.41: Predicted temporal and spatial variations in temperature (top) and dissolved oxygen (bottom) in the Nakai Reservoir 88 Figure 3.42: Results of water quality measurement in the Nam Kathang and Xe Bang Fai 91 Figure 3.43: Predicted evolution of dissolved oxygen in the Nam Kathang for both the CWR and Petit Saut for the month of April 92 Figure 3.44: The evolution of dissolved oxygen in the Xe Bang Fai for various CWR and Petit Saut scenarios 93 Figure 3.45: Predicted evolution of dissolved oxygen in the Xe Bang Fai for both the CWR and the Petit Saut for the month of April 93 Figure 3.46: Section showing water level drawdown over long section from Intake to Dam Site 94 Figure 3.47: Water quality sampling sites proposed for surface water 96 Figure 3.48: Fish distribution survey sampling site locations (Project Area & Surrounds) 97 Figure 3.49: Catchment area of additional fish distribution surveys (Houapahn & Xieng Khouang Provinces, Lao PDR) 100 Figure 3.50: Catchment area of additional fish distribution surveys (Savannakhet Province, Lao PDR) 100 Figure 3.51: Fisheries monitoring sites. 102 Figure 3.52: Forest types & land use within the Project area 112 Figure 3.53: Historical clearing on the Nakai Plateau, 1973-2003. 117 Figure 3.54: Percentage change in land cover over time 118 Figure 3.55: Percentage of area cleared (1973-2003) 118 Figure 3.56: Downstream channel alignment and habitat/land use types 119 Figure 3.57: Habitat areas impacted within the NNT-PHP Corridor. 127 Figure 3.58: Regional Protected Areas. 128 Figure 3.59: Historical clearing 1973-present. 129 Figure 3.60: Area to be cleared for construction of the Nakai Dam 134 Figure 3.61: Reservoir filling 138 Figure 3.62: Alignment of roads to be upgraded and new roads showing estimated loss of vegetation 141 Figure 3.63: Alignment of the 115 kV & 500 kV Transmission Lines 143 Figure 3.64: Alignment of 115 kV & 500 kV Transmission Lines showing estimated loss of vegetation 145 Figure 3.65: Category 1 & 2 potential area to be cleared for the 500 & 115 kV line 146 Figure 3.66: Category 2 potential area to be cleared for the 500 kV line 146 Figure 3.67: Electric fields double-circuit 500 kV Transmission Line 147 Figure 3.68: Electric fields double-circuit 115 kV Transmission Line 147 Figure 3.69: Magnetic field profile across the easement for 500 kV Transmission Line, based on a load current of 2000 A 148 Figure 3.70: Magnetic field profile across the easement for 115 kV Transmission Line, based on a load current of 645 A. 148 Contents Figure 3.71: Vegetation types within and adjacent to proposed resettlement area, with village locations and resettlement sites 149 Figure 3.72: Plateau PCR Sites 153 of Figure 6.1: Key organizations 186 Figure 6.2: HCC EMMP structure 187 Figure 6.3: EMU overall organisation 188 ableT xiv Table of Contents Table of Contents List of Tables Table 2.1: Summary of ranking of hydropower projects for export 9 Table 2.2: Technical data for selected Nam Theun 2 alternatives 10 Table 2.3: Lessons Learnt from other projects 12 Table 2.4: Turbine technical data 16 Table 2.5: Tentative schedule for Project construction 22 Table 2.6: Summary of economic analysis of the environmental and social impacts by the World Bank 30 Table 3.1: Comparison of generation per area flooded of several hydropower projects 34 Table 3.2: Cumulative Impacts of Anticipated Regional Developments Including Nam Theun 2 Project 37 Table 3.2 (cont.): Cumulative Impacts of Anticipated Regional Developments Including Nam Theun 2 Project 38 Table 3.3: Potential erosion rates 42 Table 3.4: Loss of storage volume (million m3) 42 Table 3.5: Sedimentation distribution in the Nakai Reservoir 42 Table 3.6: Predicted Width Increase in the Xe Bang Fai with Regime and Tractive Force Approaches 45 Table 3.7: Mean monthly rainfall at representative stations with years of operation in parentheses (units: mm) 46 Table 3.8: Highest recorded rainfall in the Nam Theun region 46 Table 3.9: Mean relative humidity (%) 48 Table 3.10: Temperature at Nakai Tai (°C) 48 Table 3.11: Temperature at Nakon Phanom (°C) 48 Table 3.12: Class A pan evaporation data (mm) 49 Table 3.13: Open water evaporation (mm) 49 Table 3.14: Temperature variations 50 Table 3.15: Catchment areas 51 Table 3.16: Flood frequencies estimates for the Nam Theun at the Nakai Dam site 52 Table Table 3.17: Nakai Dam site probable maximum flood estimates 52 Table 3.18: Results of regional flood frequency analysis of the Xe Bang Fai at Mahaxai 53 Table 3.19: Flood frequency estimates for the Mekong River 54 of Table 3.20: Indicative minimum and maximum Regulating Dam discharges for a percentage of secondary energy generated. 57 Contents Table 3.21: Water level increases in the Xe Bang Fai at Mahaxai 58 Table 3.22: Effect of Riparian Release on Flow Rates Downstream of the Confluence with the Nam Phao 66 Table 3.23: Nam Theun/Nam Kading present flow (m3/s) 68 Table 3.24: Summary of community use of riparian resources 69 Table 3.25: Surveyed population and resource utilisation 70 Table 3.26: Ranked Importance of Waterbodies 70 Table 3.27: Mean % of fishers and mean annual fish catch from each waterbody by village zone 71 Table 3.28: Percentage of fish catch and aquatic products consumed and sold, by village zone 72 Table 3.29: Mean % of fishers and mean annual aquatic products catch from each waterbody by village zone 73 Table 3.30: Contribution of fish and aquatic products to HH income 73 Table 3.31: Other uses of the Nam Theun (dashed (-): do not use; cross (x): use) 74 Table 3.32: Comparison of present and future average dry and wet season flows 75 Table 3.33: Example of Wetted Perimeter Analysis at IFR S1 75 Table 3.34: Summary of wetted perimeter analysis for 2m3/s Riparian Release 76 Table 3.35: Future flood event occurrence in the Nam Theun and Nam Kading 76 Table 3.36: River channel hydraulic parameters for the future average minimum flows 77 Table 3.37: Comparison of present and future flood peaks 77 Table 3.38: Comparison of present and future MARs (1986-2003) 77 Table 3.39: Fish species potentially vulnerable to low flows (KBR, 2004) 79 Table 3.40: Estimated value of fisheries loss for the riparian release of 2 m3/s 80 Table 3.41: Estimated value of aquatic products loss for the riparian release of 2 m3/s 82 Table 3.42: Summary of wetted perimeter analysis for the trade-off 83 Table 3.43: Impacts on Fisheries Production for different riparian releases 84 Table 3.44: Trade-off analysis of different riparian release regimes 84 Table 3.45: Summary of water quality in the Nam Theun, Nam Kathang and Xe Bang Fai during 2001 (Hydreco 2001a and b) 86 Table 3.46: Proposed suite of parameters for surface water monitoring 95 Table 3.47: Suite of parameters proposed for groundwater monitoring 95 Table 3.48: Lao PDR water quality targets for rural drinking water 97 Table 3.49: Fish standing stock per habitat in the Nam Kading/Nam Theun basin 102 Table 3.50: Fish species of the Nam Theun basin, their known or guessed adaptability to reservoir conditions and distribution 106 Table 3.51: Main potential Impacts by river sector 109 Table 3.52: Wildlife species of global and national conservation significance in the NNT NBCA and on the Nakai Plateau 111 Table 3.53: Occurence and account of loss of habitats in the Project area 112 Table 3.54: Key bird species recorded from flowing and non-flowing wetlands on the Nakai Plateau. 115 Table 3.55: Key mammal species recorded from flowing and non-flowing wetlands on the Nakai Plateau. 115 Table of Contents xv EAMP Main Text Table 3.56: Habitat types of the Nam Theun Gorge 116 Table 3.57: Habitat types for the dividing hills 116 Table 3.58: Summary of thematic habitats found in the Project Footprint (based on FIPD, 2002) 122 Table 3.59: Thematic habitat types ranked by area to be affected by the Project 123 Table 3.60: Extent of natural habitats & disturbed habitats within & outside of the inundation area 123 Table 3.61: Fragmentation of habitats caused by the Project 124 Table 3.62: Degradation of natural habitats in Transmission Line Easements 125 Table 3.63: Habitat occurrence and degradation for Bolikhamxay, Khammouane and Savannaket Provinces 126 Table 3.64: Adequacy of the NNT NBCA as an offset for Project impacts (ha) 129 Table 3.65: Sub-plans of the HCCEMMP for implementing protection and mitigation measures 133 Table 3.66: Potential sources of spoil and disposal sites 136 Table 3.67: Dates of water level meeting target levels for each calendar month 137 Table 3.68: Design criteria for roads 139 Table 3.79: Impacts and mitigation strategies for road construction and upgrading 142 Table 3.70: Limits of Exposure to Electric and Magnetic Fields 148 Table 3.71: Impacts and mitigation strategies for the Transmission Lines 148 Table 3.72: Vegetation within the proposed resettlement area 150 Table 3.73: Impacts and mitigation environmental protection at the resettlement sites 151 Table 3.74: General mitigation measures of the PCR Plan. 155 Table 3.75: Active ingedients not acceptable to NTPC 156 Table 4.1: Resettlers preferences considered in the selection of prospective resettlement sites. 163 Table 5.1: Project stakeholders 172 Table 5.2: Stakeholders, their interests and involvement in the consultation and disclosure process (source: SDP, April 2004) 173 Table 5.3: Consultative mechanism used with key stakeholders 174 Table 5.4: Media relations since August 2000 175 Table 5.5: Schedule for consultation and disclosure of the EAMP. 176 Table 5.6: Summary of disclosure plan for the EAMP 177 Table 5.7: Sections of the EAMP to be translated into Lao 177 Table 5.8: Concerns and issues raised during the 2004 International Workshops (non exhaustive). 179 Table 5.9: Disclosure of past and future drafts of the EAMP 180 Table 5.10: Stakeholders concerns and influence on Project planning 181 Table 5.11 Review of PCPP by Franklin (1997) 182 Table 6.1: Environmental management tasks to be undertaken 189 Contents Table 6.2: Key tasks and responsibilities of EMU teams 190 Table 6.3: Wildlife programme schedule 196 of Table 6.4: Mitigation Budget 202 Table 6.5: Implementation responsibilities and cost of mitigation 203 ableT xvi Table of Contents Table of Contents List of Plates Plate 1: Section Site S1, showing both pool and Rapid habitats 67 Plate 2: Section Site S2/3, showing both pool and Rapid habitats 67 Plate 3: Section Site S4, showing both pool and rapid habitats 68 Plate 4: Section Site S5, showing both pool and rapid habitats 68 Plate 5: Rapids on the lower Nam Theun near Ban Katok (Kottelat) 97 Plate 6: Waterfall and rapids in the middle Nam Theun, upstream of the confluence with the Nam Phao (Kottelat) 98 Plate 7: Sandbar at the confluence with the Nam Phao (Kottelat) 98 Plate 8: Nam Theun upstream of Ban Thalang, on the Nakai Plateau(Kottelat) 98 Plate 9: Swamps on the Nakai Plateau, east of Ban Boua Kham (Kottelat) 98 Plate 10: Waterfall in the headwaters of the Nam Theun (Kottelat) 99 Plate 11: Rocky Stream in the headwaters of the Nam Theun (Kottelat) 99 Plate 12: Rapids in the headwaters of the Nam Theun (Kottelat) 99 Plate 13: The lower Xe Bang Fai, near its mouth (Kottelat) 99 Plate 14: Middle Xe Bang Fai ­ exit of the underground course (Kottelat) 100 Plate 15: Upper Xe Bang Fai near Phou Taloun (Kottelat) 100 Plate 16: Luciocyprinus striolatus Cui & Cui, 1986. Found in the Lower Nam Theun. 101 Plate 17: Scaphognathops theunensis Kottelat, 1998. Found in the Lower and Middle Nam Theun, and on the Plateau. 101 Plate 18: Juvenile and adult Tor ater Roberts, 1999. Found in the Upper Nam Theun. 101 Plate 19: Nam Theun downstream of the dam showing mixed deciduous/dry evergreen forest 113 Plate 20: Nam Theun near Ban Thalang showing riverine/ bamboo forest 113 Plate 21: Grassland typical of the Nakai Plateau 113 Plate 22: Wetlands on the Nakai Plateau 114 Plate 23: Agricultural land on the Nakai Plateau 114 Table Plate 24: Degraded forest area on the Nakai Plateau 114 Plate 25: Archaeological site AS-2, Pha Phen 152 Plate 26: Historical site HS-6, Kouan Ku 152 of Plate 27: Spirit site, Phi Meuang 154 Contents Plate 28: Religeous site, TS-6, an abandoned temple 154 Plate 29: Cemetery site C-34 154 Plate 30: Cultural site CS-24, Tham Phra 154 Plate 31: Nam Theun between the Nakai Dam site and the confluence with the Nam Phao 162 Plate 32: Nam Theun between the Nam Phao and Nam Gnouang 163 Plate 33: General layout of the Pilot Village showing house locations, farm plots and the irrigation reservoir. 164 Plate 34: A comparison of Pilot Village housing with the current standard on the Nakai Plateau 164 Table of Contents xvii EAMP Main Text Contents of ableT xviii Table of Contents Acronyms Acronyms ADB Asian Development Bank AIT Asian Institute of Technology ASEAN Association of Southeast Asian Nations BOOT Build-own-operate-transfer CA Concession Agreement CBD Convention on Biological Diversity CEC Continuing Education Centre (of AIT) CPUE Catch per Unit Effort CITES Convention on International Trade in Endangered Species CWR Centre for Water Research (University of Western Australia) DANIDA Danish International Development Agency DSPOE Dam Safety Panel of Experts DSRP Dam Safety Review Panel EAMP Environmental Assessment and Management Plan EDF Electricité de France EDL Electricité du Laos EGAT Electricity Generating Authority of Thailand EGCO Electricity Generating Public Company Limited Acronyms EIA Environmental Impact Assessment El Elevation above sea level in metres EMDP Ethnic Minorities Development Plan EMO Environmental Management Office (of NTPC) EMU Environmental Management Unit (of STEA) EPL Environmental Protection Law ESMP Environmental and Social Management Plan FAO Food and Agricultural Organisation FINNIDA Finnish Department for International Development Cooperation FSL Full Supply Level GHG Greenhouse gases GNI Gross national income GNP Gross national product GMS Greater Mekong Sub-Region GOL Government of Lao PDR GTZ German Technical Cooperation HC Head Contractor HCC Head Construction Contract HCCEMMP Head Construction Contractor's Environmental Management and Monitoring Plan IAG International Advisory Group IDA International Development Association IPP Independent power project/producer ITCZ Inter tropical Convergence Zone ITD Italian-Thai Development Public Company Limited IUCN International Union for Conservation of Nature JICA Japanese International Cooperation Agency Lao PDR Lao People's Democratic Republic LWU Lao Women's Union xix EAMP Main Text MAF Ministry of Agriculture and Forestry MEC Malaysian Environmental Consultants MESAS Multinational Environmental & Social Assessment Services MIC Ministry of Information and Culture MIH Ministry of Industry and Handicras MOSES Multi-Objective Scenario Evaluation System MOL Minimum Operating Level MOU Memorandum of Understanding MW Megawa MWL Maximum Water Level MRC Mekong River Commission NBCA National Biodiversity Conservation Area NCC National Control Centre (of EGAT) NEAP National Environmental Action Plan NGO Non-governmental organisation NNT NBCA Nakai-Nam Theun NBCA NTEC Nam Theun 2 Electricity Consortium NTFP Non-timber Forest Product NTPC Nam Theun Power Company Limited NTSEP Nam Theun Social and Environmental Project NTU Nephrometric Turbidity Units PAP Project Affected Person PCB Polychlorinated Biphenyls PCPP Public Consultation & Participation Process PCD Public Consultation & Disclosure PCRS Physical Cultural Resources Survey PIC Project Information Centre Acronyms PMF Probable maximum flood POE Panel of Experts PMF Probable Maximum Flood PMP Probable Maximum Precipitation PPA Power Purchase Agreement QA International Standards Quality Assurance RAP Reselement Action Plan RMU Reselement Management Unit SCADA Supervisory Control and Data Acquisition SCOD Scheduled Commercial Operation Date SDP Social Development Plan SEMFOP Social and Environmental Management Framework and Operation Plan SKM Sinclair Knight Merz SMEC Snowy Mountain Engineering Corporation STEA Science, Technology and Environment Agency TEAM Team Consulting Engineering and Management Co Ltd THPC Theun Hinboun Power Company UNDP United Nations Development Programme UNICEF United Nations Children's Fund USAID United States Agency for International Development WCS Wildlife Conservation Society WHO World Health Organisation WMPA Watershed Management and Protection Authority WWF World Wildlife Fund xx Preface Preface Project History Project reservoir will lie, and in the Nam Theun watershed above T the proposed reservoir. In June 1991, GOL modified the proposed he Mekong Secretariat identified the potential for hydro- NakaiPlateauandNamTheunNationalBiodiversityConservation power development on the Nam Theun and Nam Kading Areas (NBCAs) by combining parts of both into the single Nakai river systems in the 1970s, following implementation of the Nam Theun NBCA (NNT NBCA). The NNT NBCA was gazeed Nam Ngum Hydropower Project in the Lao People's Democratic in October 1993 along with 17 other NBCAs throughout the coun- Republic (Lao PDR). Motor Columbus, a Swiss engineering firm, try and they, together with two other NBCAs added in 1995-1996, was engaged by the Mekong Secretariat in the early 1980s to inves- cover some 12.5% of the land area of Lao PDR. tigate three projects on the Nam Theun. Subsequently, in 1984 and 1986 the Australian firm, Snowy Mountains Engineering Corpora- In addition, during MOU negotiations for development of the tion (SMEC), performed geotechnical investigations in the area of Project, GOL identified a number of important Project-specific the proposed Nam Theun 2 Hydroelectric Project (the Project) dam issuesrelatingtoenvironmentalandsocialimpacts.Theseincluded site.In1991,theGovernmentofLaoPDR(GOL),withsupportfrom i) the reselement of 17 villages located in the inundation area; ii) the World Bank and the United Nations Development Programme flooding along the Xe Bang Fai; iii) re-routing of Road 8B around (UNDP), commissioned SMEC to undertake a Project Feasibility the proposed inundation area; and iv) development of measures Study (SMEC, 1991). This study included an Environmental Status aimed at compensating for the loss of flora and fauna both in the Report, which was the first evaluation of environmental issues for inundation area and below the dam. the Project. In 1993, GOLnegotiated with SMEC and the Transfield Group to develop a Memorandum of Understanding (MOU) for Involvement of the World Bank & First constructing and operating the Project. Another group, consisting Environmental Assessments of Transfield, Electricité de France (EDF), Italian-Thai Develop- ment Public Company Limited (ITD), Phatra Thanakit and Jas- In late 1994, GOL invited the World Bank to become involved mine International replaced the original consortium of SMEC and in the Project, both as a provider of funds for GOL's stake in the Transfield in 1994. The new consortium, known as the Nam Theun Project and as country-risk loan guarantor. During its initial visit, 2 Electricity Consortium (NTEC), began negotiating a power pur- the World Bank mission identified that environmental and social Preface chase agreement with Electricity GeneratingAuthority of Thailand impact assessments would be required for evaluation. Further (EGAT). By early 1994, the build-own-operate-transfer (BOOT) environmental and social assessment work was then targeted to project concept with GOL equity was firmly in place. Aer May address World Bank Safeguard Policies and Directives. NTEC 1997, the Asian economic crisis affected EGAT's energy demand engaged TEAM Consultants of Thailand (TEAM) to prepare a forecast, and GOL and the Royal Thai Government agreed to preliminary environmental assessment, which was released in divide the power purchase scheme into two stages ­ 1,600 MW by November 1994. TEAM, supported by EDF and SMEC, began to December 2006 and a further 1,700 MW by March 2008. GOL, the obtain information about the hydrology of the Nam Theun and World Bank and NTEC continued to undertake further assessment undertook dry season investigations in 1994 and 1995. Based on of both the economic viability and the potential environmental and this information, a second preliminary environmental assessment social impacts of the Project. Several studies to evaluate potential report was completed in April 1995. In November 1995, the World alternatives were started at that time, including a Study ofAlterna- Bank issued a list of outstanding concerns, including the need tives by Lahmeyer and Worley International (1998), which formed for an Alternatives Study that ranked power generation projects, the primary basis for selecting the Nam Theun 2 Project. Subse- an Economic Impact Analysis and an Environmental and Social quently, the World Bank commissioned a study to determine the Project. ranking of potential hydropower projects throughout Lao PDR (Lahmeyer and Worley International, 2000), which has since been Nam Theun Social & Environmental Project updated. In 2001, Electricity Generating Public Company Limited (EGCO) replaced both Phatra Thanakit and Jasmine International A November 1996 World Bank mission developed a concept for in NTEC, which continued to develop the Project. On January 1st project-based assistance to GOL, known as the Nam Theun Social 2004, the responsibilities of NTEC were transferred to the Nam and Environmental Project (NTSEP), to be funded through an Theun 2 Power Company Limited (NTPC), a special purpose com- International Development Association (IDA) credit and to be pany that was established under the laws of the Lao PDR to fur- treated as GOL equity in the Project, provided that the activities ther develop, construct, own and operate the Project, and which is to be funded were part of both the Environmental Assessment wholly owned by EDF, Electricité du Laos, EGCO and ITD. and Management Plan and the Social Development Plan. The first studies identified a number of peripheral impacts that would GOL Environmental & Social Concerns occur during the construction period. These studies also recom- mended the development of corridors between the NBCAs that Prior to considering development of the Project, GOL began surround the Project site. In addition, the World Bank established instituting a series of national protected areas within Lao PDR in a fund to develop a management plan for the NNT NBCA. The response to concerns over ongoing uncontrolled habitat loss and plan was developed by IUCN in association with the Wildlife Con- hunting of wildlife. The International Union for Conservation of servation Society (WCS). When the loan guarantee for the Project Nature (IUCN), of which GOLhas been a State member since 1969, is received from the World Bank, the initial programmes under the proposed the formation of more than 30 protected areas and forest NTSEP will be funded. The funding received from the World Bank reserves in Lao PDR, including on the Nakai Plateau, on which the will enable GOL to begin detailed planning for the reselement Project History xxi EAMP Main Text programmes, allow them to manage the non-labour population EMDP) and the SEMFOP form a suite of documents addressing influx associated with the construction period and provide addi- environmental and social issues in the Project area.They are the tional funding for continuing with the implementation of the NNT synthesis of studies that were conducted and updated from the NBCAmanagement plan. beginning of the Project. All documents in the suite have under- gone intensive review processes that have involved various stake- Development of the EAMP holders, including the Project-affected people, GOL, the Panels of Experts and the World Bank. Once the management plan was prepared for the NNT NBCAand the format for the NTSEP was established, NTEC began to search The documents of the Suite address different needs. Environmen- for a company to prepare the full Environmental Assessment and tal issues are developed in the EAMP, the presentation of the NNT Management Plan (EAMP). NBCAand of its proposed management are dealt with in the SEM- Seatec International, Thailand, in association with Sinclair Knight FOP, social and reselement issues are presented in the SDP, and in Merz (SKM), Australia, was selected to prepare the EAMP. A first particular in the RAP, while ethnic minorities issues are addressed dra EAMP was completed in May 1997 and submied to the in the EMDP. In order to avoid excessive repetition and volumi- World Bank and GOL for review and comment. GOL organisa- nous documentation, topics discussed in one document are only tions that reviewed the initial dra included the Science, Technol- briefly outlined in other documents and the reader is referred to ogy and Environment Agency (STEA), the Ministry of Agriculture the relevant location of the detailed discussion. The reader will and Forestry (MAF), and the Ministry of Industry and Handicras have to pick up the right document to gain knowledge of specific (MIH). In response to the comments and recommendations from issues and impacts and the ways in which the Project is proposing the World Bank and GOL agencies, a number of additional stud- to deal with them. ies were commissioned to provide an evaluation of critical envi- In addition to the EAMP, SDP and the SEMFOP documents, there ronmental, social and economic issues. Theses included updating is also the Summary Environmental and Social ImpactAssessment information on water quality from previous modelling, defining (SESIA). This stand-alone document serves as an integrated sum- water quality impacts in the Xe Bang Fai, explaining the hydro- mary of the EAMP, SDP and SEMFOP and takes the place of an logical model, presenting reservoir management issues, review- executive overview. ing downstream flooding impacts and mitigation, and updating knowledge of aquatic biodiversity based on additional fish sur- Organisation of the Report veys. A second dra EAMP was produced in 2000 and a third in 2001. The EAMP presents the environmental impacts aributable to These dras were based on the results of new studies and on the Project during the construction and operation phases, and the reviews and comments received on earlier versions, and included proposed mitigation measures. It includes i) a description of exist- various design changes incorporated into the Project since 1997. ing environmental conditions and the identification of significant refaceP The design changes were based on EGAT's request to operate the environmental issues; ii) an evaluation of the potential for envi- Project as an intermediate peaking facility rather than as a base ronmental impacts; iii) a short presentation of the existing social load plant. The main additions to these versions were related to i) conditions and issues; and iv) the identification of opportunities the amendment of the operating regime to cease operation when for avoiding, mitigating and compensating for those impacts, and flooding in the Xe Bang Fai is imminent; ii) the modification of for enhancing environmental conditions. release equipment design to ensure beer water quality for release The first volume, the EAMP Main Text, consists of six chapters: into the Nam Theun and the Xe Bang Fai; iii) improved mitigation Chapter 1: Project Background, provides a brief description of the measures; and iv) measures to improve GOLinstitutional capacity to handle the Project. Afourth dra of the EAMP was prepared by Project. It establishes the need for the Project, focusing on its eco- Seatec International in March 2003 to update the previous versions nomic viability, as well as its environmental and social acceptabil- and integrate the comments expressed by various parties, includ- ity. This chapter also introduces the reader to the policy, legal and ing the World Bank and the Panel of Experts. Dr John R. Bizer, who administrative framework of GOL. acted as the chief rewriter of the EAMP, prepared the fih dra in Chapter 2: Analysis of Alternatives and Project Description, pro- October 2003 and the March 2004 version. Various experts, pre- vides a description of the Project alternatives and justification for sented in Annex B, assisted all the teams with preparation of the the proposal put forth by NTPC. It also presents the Project fea- various dras of the EAMP. tures in detail. This is followed by details of the Project's construc- tion, operation and decommissioning. Finally a description of the The Safeguard Documents study areas that were identified for evaluating the impacts of the Project is presented. Over the course of the Project's development, the need for new Chapter 3: Assessment of Environmental Impacts, addresses glo- and additional studies has emerged. Additional studies have so bal and regional issues related to the Project, such as greenhouse far included the Reselement Action Plan (RAP) first released in gases and biodiversity. The analysis then presents the baseline 1997 and updated in 1999, 2002 and 2003, and the preparation in environmental conditions, the various impacts of the Project and 2002 and 2003 of an Ethnic Minorities Development Plan (EMDP) mitigation measures for the construction and operation phases. both updated in 2004 and 2005. In May 1998, IUCN prepared a revised Environmental and Social Management Plan (ESMP) for Chapter 4:Assessment of Social Impacts, briefly presents the social the NNT NBCA, which was then updated in 1999, and in 2000 context, social impacts and how social mitigation and manage- the GOL issued an updated Operational Plan. The updated NNT ment measures have been integrated into the Project design in the NBCA Management Plan together with the updated Operational various project areas. Plan, formed the basis for the development of the Social and Envi- Chapter 5: Public Consultation and Disclosure, describes the proc- ronment Management Framework and first Operational Plan ess of disseminating information about the Project to the various (SEMFOP) in 2002, updated in 2003, 2004 and 2005. The EAMP, the stakeholders, the main outputs of these briefings and meetings Social Development Plan (SDP, which includes the RAP and the and how feedback was incorporated into Project design. xxii Development of the EAMP Preface Chapter 6: Environmental Management Plan, summarises the pro- the Lao name of a river, for example the text uses "Nam Theun" visions of the environmental mitigation and management plan. It identifies the responsibilities of the various parties to the Project, instead of "Theun river". Similarly, the word Ban, meaning vil- outlines the basic programmes and includes potential adaptive management. lage, is also used throughout the EAMP document. National Bio- The Conclusion summarises the main environmental impacts of the Project together with the associated mitigation measures and diversity Conservation Area (NBCA) and National Protected Area management plan that have been designed to minimise adverse effects. (NPA) have the same meaning in the text of the document and are The second volume of the EAMP, Annexes, contains supporting documentation for various issues that are addressed in the Main transposable. Text. Throughout the EAMP the Lao words Nam, Xe and Houay may be Comments and questions on this document can be sent to found. They all mean "river" in the Lao language. To avoid repeti- tion and confusion, the English word "river" is not repeated aer eamp@namtheun2.com. Preface Procedures for Questions & Answers xxiii EAMP Main Text refaceP xxiv EAMP Main Text Project 1. Project Background Background Table of Contents Brief Description 2 Project Equity 2 Need & Rationale 2 Potential Contribution to the Economy of Lao PDR 3 Lao Policy, Legal & Administrative Framework 3 National Laws 3 GOL Resettlement Policy 5 Responsibilities of GOL Under International Treaties 5 Enforcement & Implementation of the Law Relative to the Project 6 T he Government of the Lao People's Democratic Republic (GOL) and the Nam Theun 2 Power Company Limited (NTPC) entered into a concession agreement on October 3, 2002 allowing NTPC to build-own, operate and transfer the Nam Theun 2 Hydroelectric Project (the Project) in Lao PDR. This chapter introduces the Project within the socio-economic context of Lao PDR. The policy and legal and administrative framework, in which the Project is set, are also briefly presented. Brief Description 1 EAMP Main Text Brief Description Project Equity Lao PDR is situated in the centre of mainland SoutheastAsia. Cov- NTPC is a limited liability company that was incorporated under Background ering an area of some 236,800 km2, it is marginally smaller than the Lao law on August 28, 2002. Its registered office is currently in United Kingdom. Landlocked and mountainous, almost all of Lao Vientiane, Lao PDR. The purpose of NTPC is to implement the PDR is located within the lower watershed of the Mekong River, Project. NTPC is owned by EDF International (EDFI) of France (a wholly owned subsidiary of EDF), Electricity Generating Public rojectP which borders or traverses much of the length of the country in a general north to south direction. The population of Lao PDR is Company Limited (EGCO) of Thailand, Electricité du Laos (EDL) of the Lao PDR and Italian-Thai Development Public Company estimated at 5.4 million, with most of the people living in sparsely Limited (ITD) of Thailand, with the following shareholdings: distributed villages that can be difficult to access due to terrain and EDFI, 35%; EDL, 25%; EGCO, 25%; and ITD, 15%. the monsoonal climate. Lao PDR is bordered by the Chinese prov- The shareholders of NTPC, including the parent companies and ince of Yunnan to the north, Vietnam to the east, Cambodia to the associated companies within the respective group, have extensive south, Thailand to the west and by Myanmar to the northwest. experience in the design, construction and operation of large-scale The majority of the Project will be located in Khammouane Prov- hydroelectric power projects. ince, in central Lao PDR. A main dam on the Nam Theun, a tribu- The total cost of the Project is estimated at US $1.3 billion, inclu- tary of the Mekong River, will create a 450 km2 reservoir (full sup- sive of construction costs, mitigation and compensation measures, ply level) on the Nakai Plateau with a total storage volume of 3,910 reselement and contingency funding. Base equity will represent million m3. Water from the reservoir will drop approximately 350 approximately 30% of this total, while Thai and US denominated m to a power station located at the base of the Nakai Plateau near debt will each represent approximately 35%. the town of Gnommalat. The water discharged from the power sta- tion will then flow into a regulating pond and from there to the Xe Need & Rationale Bang Fai via a 27 km-long channel. The power station, comprising LaoPDRisofficiallyrecognisedasaleastdevelopedcountry(LDC) 4 Francis and 2 Pelton turbines, will have a generating capacity of and relies heavily on external aid. Almost half of its 5.4 million 1,080 MW (net 1,070 MW). Approximately 95% of the generating people live in poverty. In 2001, gross national income per capita capacity and electrical energy made available by the Project will (GNI, formerly GNP per capita) was US $290 (World Bank, 2001). be sold to the Electricity GeneratingAuthority of Thailand (EGAT) The United Nations Development Programme (UNDP) ranks Lao and the remaining 5% will be sold to Electricité du Laos (EDL). PDR's "Human Development Index" at number 135 out of a total The electricity generated for sale to Thailand will be delivered by a of 175 countries evaluated, making Lao PDR the lowest ranked 138 km-long, double circuit, 500 kV transmission line. The transfer country in Southeast Asia (UNDP Human Development Report, point is to be located at the Lao­Thai border on the Mekong River, 2003). GOLis actively seeking foreign investment opportunities to help develop the nation's economy and li it out of LDC status by near the city of Savannakhet. A 70 km-long, 115 kV transmission the target date of 2020. line will deliver electricity from the power station to the Thakhek Lao PDR has few options to secure sustainable and environmen- substation for connection to the EDL system. tally sound economic and social development. Due to its low population and lack of skilled workers, the country's ability to develop labour intensive industries is limited, while its minera- logical resource base is as yet relatively undeveloped. In addition to the mining potential, opportunities also exist for timber harvest- ing, tourism and hydroelectric power. Historically the use of forest resources has not been sustainable. In many instances, logging operations have led and continue to lead to extensive degradation of habitats and loss of soils due to ero- sion.Amajor drain on wildlife stems from the sale of wildlife both domestically and to neighbouring countries. Recently, GOL estab- lished a legal framework for monitoring the harvest of timber and is actively developing procedures to enable the sustainable use of forests, with the assistance of a number of donor organisations, including the World Bank, Finnish Department for International Development Cooperation (FINNIDA) and German Technical Cooperation (GTZ). In light of the potential further degradation of the environment through uncontrolled logging and the wildlife trade, the development of hydroelectric power is one option that will enable GOL to obtain sustainable foreign exchange revenue and to improve the country's socio-economic profile. The development of hydroelectric power facilities within Lao PDR represents a highly appropriate method of achieving sustainable social and economic development. With neighbouring Thailand needing large amounts of competitively priced electricity, and identified feasible hydroelectric potential in Lao PDR exceeding 23,000 MW, the export of hydroelectric power is presently seen as the most appropriate way for GOLto best achieve its development Figure 1.1: Location of the proposed Nam Theun 2 Hydroelectric Project goals. 2 Brief Description EAMP Main Text Project Potential Contribution to the Economy of Lao PDR Background The Governments of the Lao PDR and the Kingdom of Thailand entered into a MOU in 1996 for the development and supply of up to 3000 MW of electricity from Lao PDR to Thailand by the year 2006. GOL and the Government of Thailand subsequently agreed in 1998 to increase the export target to 1,600 MW by December 2006 and 1,700 MW by March 2008. Under that MOU the Project has been nominated by GOL as a supplier of electricity to Thailand. The MOU represented the for- malisation of a long history of bilateral electricity trades. Thailand began buying electricity from Lao PDR in 1971 (from the Nam Ngum 150 MW hydroelectric project) and has continued to pur- chase electricity since, notwithstanding minor disputes between the two countries during the mid-1970s. GOL has likewise been purchasing low voltage electricity from Thailand to supply its bor- der provinces for many years. Whilst Thailand presents a long-term viable customer for power Figure 1.2: Parties to the Project generated from Lao PDR, importing 2,806 GWh of power from CA: Concession Agreement; PPA: Power Purchase Agreement; EDFI: Electricité de the Lao PDR in 2002, the current trade represents a fraction of France International; EDL: Electricité du Laos; EGCO: Electricity Generating Public the potential electricity exchanges between the two countries. As Company Limited; ITD: Italian-Thai Development Public Company Limited of today, only the 214 MW Theun-Hinboun and 126 MW Houay Lao Policy, Legal & Administrative Ho projects (i.e. 340 MW or just over 10% of the capacity agreed Framework under the MOU) have been constructed and the target figure of 1,600 MW by 2006 will not be met. However, thanks to its strong This section aims at briefly summarising the Lao laws, decrees and economic fundamentals and its particular focus on Lao PDR's regulations that have been enacted in relation to environmental social and economic development, the Project has remained under aspects and are relevant to the Project, as well as the international active development since 1994 and is now in the process of being conventions that impose obligations on GOL in relation to envi- implemented. ronmental issues. NTPC's assessment of framework and theADB's While the country has many potential hydroelectric projects, the assessment of capacity will be incorporated into this section when Project has, through the export of 995 MW of generating capacity they become available. and electrical energy to EGAT and the supply of 75 MW of generat- The Lao PDR Environmental Protection Law (EPL) promulgated ing capacity and electrical energy to EDL, long been recognised by in 1999 is the basis of Lao legislation regarding protection of the independent experts as the one project with the greatest potential environment. It establishes a framework for unified environmen- to achieve the development objectives of the Lao PDR. tal management of environmental resources, with the objective of preserving and facilitating sustainable use of natural resources. It has been estimated that over the life of the 25-year project con- The Science, Technology and EnvironmentAgency (STEA) of GOL cession period GOL will receive approximately US $2 billion from is responsible for implementation of the EPL. Various ministries the Project, which includes revenues from royalties (approxi- have issued guidelines for implementing provisions of the EPLbut mately US $765 million), taxes (approximately US $428 million), STEA is ultimately the agency issuing a conditional or uncondi- dividends (approximately US $729 million), watershed manage- tional environmental certificate of compliance aer reviewing the ment (US $25 million) and equity (approximately US $48 million). Environmental Impact Assessment (EIA) with the various minis- This estimate is being reassessed by the WB economic study. The tries involved. To comply with the requirements of the EPL, NTPC precise amount of revenues from the Project will depend on sev- has prepared the EIA, called the Environmental Assessment and eral factors, including the demand for energy by EGAT, as defined Management Plan (EAMP). The plan is also one of Safeguards in the Power Purchase Agreement (PPA). GOL intends to use its Documents required by the World Bank for this Project. share of revenues to develop programmes that will contribute to National Laws the alleviation of poverty through the promotion of economic and social development. Over recent years GOL has developed and updated a number of The watershed management fee is an annual contribution of regulations and policies for environmental management. This sec- US$1millionfromtherevenuesoftheProjectduringtheoperation tion presents the legislation and policies relevant to environmental phase and is in additionto the US$6.5 millionthat will be allocated management for the Project. during the construction phase for the development of the Social The Environmental Protection Law, 1999 andEnvironmentalManagementFrameworkandfirstOperational The main piece of legislation is the Environmental Protection Law, Plan (SEMFOP). These funds are to be utilised for the management which was approved on the 3rd of April 1999. Basic principles of of the 3,500 km2 Nakai ­ Nam Theun National Biodiversity Con- environmental protection are that the national socio-economic servationArea (NNT NBCA), which constitutes the majority of the development plan shall include provisions to protect the environ- watershed area upstream of the reservoir. In this way, the Project ment and natural resources; all persons and organisations resid- will contribute directly to improving local infrastructure and agri- ing in Lao PDR have an obligation to protect the environment. cultural technologies utilised by communities residing within the Whoever causes damage to the environment is responsible for the NNT NBCA, as well as protecting its biodiversity. impact under the law. Natural resources, raw materials and energy Lao Policy, Legal & Administrative Framework 3 EAMP Main Text shall be used in an economical manner to minimise pollution and construction of water reservoirs for the purpose of irrigation, con- waste and allow for sustainable development (art. 5). sumption and energy production. Medium and large-scale users Important provisions of the Law include: Development projects of the resource are restricted by permiing specific reservoir devel- Background andactivitiesthathavethepotentialtoaffecttheenvironmentshall opments (art. 17). The Law does not require the development of a require an EIA(art. 8). It is an obligation of all organisations to con- basin management plan. For hydropower development, an EIA is trol pollution in accordance with environmental quality standards required prior to development of the project. The Water Resources (art. 22) set forth in regulations by the various agencies involved. rojectP CommieeunderthePrimeMinister'sOfficeadministerstheWater In addition to the main EIA for the Project, a number of smaller Law and is responsible for review and evaluation of the EIA. environmental assessments are required under the EPL. These impact assessments will deal with the removal of vegetation for The Electricity Law, 1997 the various construction activities, the spoil disposal areas, the The Electricity Law, approved on the 12th of April 1997, provides quarries, the borrow pits, the Transmission Lines, the resele- the basis for developing a concession agreement to construct and ment villages and the construction work camps. These EIAs will operate a hydropower project (art. 11) and provides requirements be reviewed by STEAfor approval.Additionally, it is expected that for the construction of transmission lines. In both cases, the Elec- the World Bank will review these impact assessments prior to the start of construction of the Nakai Dam, the Headrace Channel, the tricity Law provides for minimal damage to the environment that Power Station, the Downstream Channel and the Transmission is to be monitored by the Environmental Management Unit in the Lines and the Mekong River crossing of the transmission lines. Hydropower Department of the Ministry of Industry and Handi- Additional impact assessments are required for the operator's vil- cras (MIH). The law requires that EIAs be prepared, particularly lage, the sub-stations and the reselement villages. for large-scale hydropower projects (art. 6, 12). The EIA requires The implementing decree of the EPL (2002) provides the legal tool incorporation of mitigation measures and requires compensation for implementation of the law. The Environmental Management for damages to the environment, people's livelihoods, and if neces- Standard (2001) stipulates the minimum requirements to develop sary relocation of affected people (art. 14, 18). The Hydropower aproject,includinganenvironmentalmanagementplanforhydro- Department within the MIH will also review the Project EIA. power projects. STEA has also developed a set of regulations for Additional Decrees conducting the environmental assessment of a proposed hydro- power project (2000, 2001). These regulations and standards estab- Implementation of the laws described above is the responsibility lish general environmental assessment requirements, including of the various ministries and agencies administering the different the timing of the environmental impact assessment in the project laws. Implementation is generally set forth in a series of decrees development cycle. They stipulate detailed project screening, ini- that formally implement them. Several important decrees relevant tial environmental examination, and EIA requirements including to the Project are described briefly in the following paragraphs. content and format of reporting and the approval of the report. PM Decree 164 of 1993 Relative to the Establishment of National The Forestry Law, 1996 Biodiversity Conservation Areas The Ministry of Agriculture and Forestry (MAF) administers the This decree legally established eighteen NBCAs throughout Lao Forestry Law, approved on the 11th of October 1996. The Forestry PDR, including the NNT NBCA and satisfies certain GOL obliga- Law includes the following general provisions: i) Forest resources tions to set aside biologically diverse areas under the Convention are comprised of all resources, whether living or non-living, that are found on forest lands, including soil, plants, water, aquatic ani- of Biological Diversity, ratified in 1996. The decree contains provi- mals and wildlife (art. 3); ii) All organisations have obligations to sions for i) the main objectives of the protected areas; ii) measures protect and conserve forest resources including watersheds, wild- and restrictions in protected areas; and iii) entrusting the MAF life and the environment (art. 8); and iii) GOL is responsible for to establish provisions, detailed rules and management plans for allocating the use of forest lands and resources. The Forestry Law each NBCA. Wrien into the decree is the planning for potential (art. 16) categorises forests in Lao PDRinto five groups: Protection, or existing uses that are feasible and appropriate in portions of the Conservation, Production, Regeneration and Degraded. In the NBCA without compromising the overriding goal of biodiversity management of forest resources, MAF has the right and responsi- conservation. Such developments and uses include hydropower bility to perform an executive, regulatory and advisory role to the projects and customary use by populations that have been resident government in the development of programmes, projects and leg- in or near the NBCAprior to their designation. islation (art. 60). As the Project will affect some forests, MAF will review the EIAs for the construction areas, the reselement areas, PM Decree 193 of 2000 Relative to the Definition of Boundaries the spoil areas, the quarry areas and the transmission lines. Most of the NNT NBCA & Corridors, Reservoir & Reselement Area of the forestlands in the reselement area on the Nakai Plateau will In order to clarify and legally define the various areas related to the likely be classified as Production Forests. These areas are adjacent Project, this decree determines the boundaries of: the NNT NBCA; to the northern end of the Nam Malou basin, which is considered two corridors between NNT NBCA and Phou Hin Poun NBCA a Wildlife Corridor and therefore should be classified as Protected and between NNT NBCA and Hin Nam Nor NBCA; the reservoir or Reserve Forests. area at full supply level; and the reselement area for the affected The Water Law, 1996 populations on the Nakai Plateau. TheLawonWaterandWaterResources(theWaterLaw),approved The area marked for removal of trees and vegetation was deter- onthe11thofOctober1996,isintendedtoassurethesustainableuse mined to be the highest elevation of the reservoir at 538 m above of water. Water use is divided into small, medium and large scale sea level. The designation of the two corridors between the three uses (art. 14) and the legislation defines the rights, obligations and NBCAs is part of the compensation for the Project. The corridors procedures for gaining approval for use of water resources (art. 4). effectively connect the three NBCAs immediately surrounding the The Water Law establishes requirements for preparation of an EIA Project. These corridors will be managed by the Watershed Man- for any large scale use of water (art. 18). The provisions include agement and Protection Authority of the NNT NBCA. 4 Lao Policy, Legal & Administrative Framework EAMP Main Text Project PM Decree 25 of 2001 Relative to the Establishment of the Nam vincial Office shall determine which parts of the reselement area Theun 2 Watershed Management & Protection Authority shall be used for what purposes. The land will then be surveyed Background Following review and negotiation by a range of stakeholders and by the Department of National Land Use and Planning, which can Government agencies, this decree established the Nam Theun 2 grant a thirty-year lease on the land for housing and agricultural Watershed Management and Protection Authority. It provides a development. The use of forestry products will be managed on a detailed definition of the Authority's objectives, goals and func- community basis through the establishment of a forestry associa- tions, and the membership of the Board of Directors that will tion, representing all of the affected families, authorised by MAF protect and manage the NNT NBCA. The responsibilities of the and further defined by the District Governor. Watershed Management and Protection Authority are described GOL Responsibilities Under International Treaties in detail in the SEMFOP. The method for implementing obligations contained in interna- Other Ministerial Decisions & Orders tional treaties to which Lao PDR is a party is an open issue within Current timber harvest policy is contained in Prime Minister's GOL. The Constitution does not specify whether Lao PDR has a Order No. 15, which specifically prohibits logging of all kinds monist system or a dualist system. The Ministry of Justice is cur- in the NBCAs and the corridors between the NBCAs. The policy rently developing provisions for regulating the ratification of trea- regarding village use of forest is contained in the Minister's Deci- ties as a dualist system. Currently, it is understood that when GOL sion 535, of the 18th of June 2001. Besides the NNT NBCA man- adopts an international convention, the legal system must conform agement objectives and specific wildlife regulations, a new policy to the provisions of the treaty and appropriate laws incorporated regarding wildlife is contained in the Ministry of Agriculture into the legal code. The National Assembly has enacted specific and Forestry Order 76. This order prohibits hunting and trading laws relative to their obligations under various international con- of aquatic and forest animals both in-country and out-country, ventions. The specific conventions and agreements presented in importation or transfer to a third country. In effect, this order pro- this section pertain to biodiversity, social development and protec- hibiting trade in wildlife establishes the basis for GOL to become tion of significant cultural resources. Although the conventions do a member of the Convention of International Trade in Endangered commit GOL to meeting the obligations, some of the conventions Species (CITES). do not currently have a basis in Lao law. GOL Resettlement Policy Convention on Biological Diversity In 1997, GOL developed a dra policy on the relocation of peo- On the 20th of September 1996, Lao PDR became a signatory to the ple directly affected by development schemes. Under the Electric- Convention on Biological Diversity (CBD) of 1992, which imposed ity Law, the Water Law and the Road Law, project developers are a number of obligations including the establishment of protected required to provide the affected population with compensation areas, the development of guidelines to manage those areas, iden- and/or replacement land for land taken from them as a result of tify and monitor components of biological diversity, and to assess the construction and operation of a project. The Dra National the environmental impact of proposed projects which may have Reselement Policy for Major Projects in Lao PDRprovides a set of adverse impacts on biological diversity. Since the 9th of July 1985 regulations for preparing and implementing an involuntary relo- Lao PDR has been a signatory of the ASEAN Agreement on the cation programme. Conservation of Nature and Natural Resources, which covered most of the basic components of the CBD. Several key pieces of Rights of ethnic groups are enshrined into the Lao Constitution of legislation were enacted to meet the obligations of the CBD: The 1991 and were reinforced in 1992 through a policy paper entitled Prime Minister Decree 164 of 1993 relative to the establishment the Resolution of the Party Central Commiee on Ethnic Affairs of NBCAs; the EPL, in 1999; and the Regulation on the Manage- over the Past Years. This policy is to be used as a reference for the ment of the NBCA, Aquatic and Wild Animals, in 2001. The regu- planning, implementation and development of compensation pro- lations provide rules on the establishment and management of the grammes. Reselement plans address social and economic rehabil- National Protected Areas. itation of the affected communities to enable them to re-establish, and possibly improve the quality of, their lives. Convention on Climate Change A reselement policy specific to the Project, prepared by the Nam On the 4th of January 1995, Lao PDR became a signatory of the Theun 2 Reselement Commiee, was issued in June 2002 by the United Nations Convention on Climate Change. Although there Deputy Prime Minister as Reselement Commiee Policy Adjust- is currently lile industry in Lao PDR, the government is respon- ment No. 1147/CPC. Its objectives centre on providing agricul- sible for assuring that future development in the country meets tural and forestry production areas and developing a compensa- the conditions of the convention. In the case of the Project, one rel- tion package for the affected populations, with the aim being to evant issue, addressed in Chapter 3, is the potential for generation upgrade and develop sustainable livelihoods. PM Decree 193 iden- of greenhouse gas from the reservoir. Some other conditions that tifies the area where the reselers are to be relocated and the Prime pertain to the Project include: Minister's supplemental Decree 37/PM approves the allocation of this area. From a legal perspective there are two key require- · Enhancement of energy efficiency in relevant sectors of the ments for the relocated populations: i) that they have some form of economy; ownership of the land; and ii) that they are able to use the natural · Protection and enhancement of sinks and reservoirs of green- house gases, taking into account commitments under relevant resources within that area. international environmental agreements; The State grants rights to individuals, families and organisations · Promotion of sustainable forest management practices, affor- to use the land pursuant to the Land Law of 1997, either as a tem- estation and reforestation; porary "right to use" for up to five years or as a thirty-year "lease". · Promotion of sustainable forms of agriculture in light of cli- The Ministry of Finance, in conjunction with the Prime Minister's mate change considerations; Office, has the responsibility for land titling, registration and leas- · Measures to limit and/or reduce emissions of greenhouse ingofland.MAFmanagestheuseofsuchland.Forthepopulations gases; and affected by the Project, Decree 37/PM specifies that the MAF Pro- · Limitation and/or reduction of methane emissions. Lao Policy, Legal & Administrative Framework 5 EAMP Main Text Convention on the Protection of the World Cultural & countries as a backup to the initial notification. Responses to the Natural Heritage notification are expected in 2004. If no responses are received, it GOL ratified this Convention on March 20, 1987. A Presidential will be assumed that there are no comments on the transmission Background decree on the preservation of cultural, historic and natural herit- line crossing and that the crossing is acceptable to all countries. age issued in 1997 (No 03/PR) outlines the regulations and meas- Disputed Territories ures for the management, conservation, preservation and use of The concern about disputed territories stems from the crossing rojectP the national heritage, including for the upgrading of movable and immovable assets with historical or cultural or natural value into of the Mekong River by the transmission line. Two towers will be the national heritage (art. 1). constructed in the river with one tower close to the Lao side and The Ministry of Information and Culture (MIC) is responsible for the other near the Thai side of the Mekong River. Although there implementing the Convention for the Protection of World Cultural is some debate as to where the actual international border occurs and Natural Heritage resources. This convention aims at the pro- within the river, both countries have accepted the positions of the tection and conservation of the world cultural and natural heritage towers relative to their national borders. Arbitrarily, the delivery including habitats of threatened animal and plant species and sites of electricity from Lao PDR to Thailand is at the midpoint between of outstanding cultural value. the two towers, which does not imply that the middle of the river An initial physical cultural survey was completed on the Nakai is the international boundary. The decision to name the midpoint Plateau in 1995. Prior to constructing the Project, a more detailed between the two towers as the delivery point to Thailand is an survey of the construction areas and the Nakai Plateau within the arbitrary determination that was agreed to by both Lao PDR and reservoir area is being conducted. The purpose and methodology Thailand. Consequently, there is no real debate about the bed of of this survey are defined in the impact assessment and manage- the Mekong River being part of either Lao PDR or Thailand, and ment chapter. no debate relative to the 500 kV transmission line crossing of the Mekong. Agreement on the Cooperation for Sustainable Development of the Mekong River Basin Other International Conventions The Agreement on the Cooperation for Sustainable Development Lao PDR has also ratified on the 14th of August 1980 the interna- of the Mekong River Basin was ratified by GOL on the 5th of April tional convention on the elimination of all forms of discrimination 1995. The primary purpose of the agreement is to ensure the sus- against women and the convention on the rights of the child on the tainable development, utilisation, management and conservation 8th of May 1991. The United Nations Children's Fund (UNICEF) of resources associated with the Mekong River. and UNDP are helping GOL to develop specific legislation related Provisions that are directly applicable to the Project include: to these two conventions. These will be taken into consideration · Cooperate in sustainable development, utilisation, manage- by the Project in due time. For the record, in 1996 Lao PDR rati- ment and conservation of water and related resources of the fied the convention on desertification, with limited relevance to the Mekong River; Project. · Assist in development of sustainable benefits to all countries Enforcement & Implementation of the Law Relative bound by the agreement; · Protect the environment, natural resources, aquatic life and to the Project ecology of the Mekong River Basin; Mechanisms for the enforcement and the implementation of the · Accept provisions outlined in the agreement relating to intra- law are being established. The ADB is currently assessing national and inter-basin diversions; capacity on this issue. The findings of this study will be incorpo- · Cooperate in the maintenance of flows on the mainstream of rated into the EAMP once they become available. The following the Mekong River; institutional measures are planned to assist in the strengthening · Avoid, minimise and mitigate harmful effects to the environ- of the environmental management of projects. STEA will take the ment; and · Ensure the Mekong River remains free from obstructions, lead in developing the necessary regulations and the development measures, and actions that may impair navigability of the of staff to implement the National Environmental Action Plan river. (NEAP). Particular importance is given to: PlanningfortheProjecthasincorporatedmanyoftheissuesrelated · Adoption of environmental assessment regulations and guide- to this agreement. In addition to the hydrological impacts on the lines for the industrial, agricultural and forestry, hydropower, Mekong River, a 500kV transmission line will cross the Mekong mining and transport sectors; River to deliver power to Thailand. The design of the transmission · Improvement and implementation of forest management and line will not affect navigability of the river. conservation policy; · Improvement of watershed management in areas with existing International Waterways and planned hydropower projects; As the Mekong River is an international waterway, to be crossed · Assistance in expanding and managing the national biodiver- by the Project's proposed 500kV transmission line, notification was sity conservation area system; sent to all riparian countries, China, Myanmar, Thailand, Cam- · Reinforcement of staff capability for participating in the envi- bodia and Vietnam, and to the Mekong River Commission. An ronmental protection aspects of development planning and initial notification was sent in 1996 to each of the countries and implementation; no response was received. A second notification was sent to the · Expansion of environmental data collection systems including Mekong River Commission by the Lao National Mekong Com- land resource/use mapping, land capability assessment and miee Secretariat in 2000 and a presentation of the Project was zoning; and given to the Joint Commiee prior to the MRC Council Meeting · Assistance with training of staff of various line agencies that in October 2000.Athird notification was sent in 2003 to each of the are involved with environmental assessment of infrastructure. 6 Lao Policy, Legal & Administrative Framework EAMP Main Text 2. Project Description & Analysis of Alternatives Analysis of Alternatives 8 Market for Power Exports from Lao PDR 8 Review of Lao PDR Candidate Projects 9 Findings of the Analysis of Alternatives 10 Project No Project Scenario 10 Evaluation of Alternative Configurations 11 Reduction in the Size of the Reservoir 11 Description Reducing Effects of Discharges to the Xe Bang Fai 11 Reducing the Impacts in the Downstream Nam Theun 13 Lessons Learned from Other Hydropower Projects 13 Description of Project Infrastructure 13 Nakai Dam & Reservoir 13 Flow Diversion 16 Power Station 16 Downstream Hydraulic Control & Conveyance 17 Ancillary Works 22 Project Construction, Operation & Decommissioning 24 Construction 24 Operation 25 Project Decommissioning 26 Location & Study Area 26 The River Basins 26 Overall Study Area 28 Economic Analysis Environmental & Social Impacts 30 I n this chapter the analytical process through which the Project was identified as being appropriate for development is described. Alternative project configurations are discussed including the implications of a "no-Project" scenario. This is fol- lowed by a more detailed description of the infrastructural com- ponents that will make up the Project. Details of the Project's con- struction, including organisation of the component contracts, its operation and eventual decommissioning are then provided. This is followed by a description of the location and the study areas potentially affected by the Project. Analysis of Alternatives 7 EAMP Main Text Market for Power Exports from Lao PDR Regional Market The Greater Mekong Sub-Region (GMS), comprising Cambodia, Lao PDR, Myanmar, Thailand, Vietnam and Yunnan Province of the People's Republic of China, is endowed with substantial but unevenlydistributedenergyreserves.LaoPDR,Myanmar,Yunnan and Vietnam all have the resources to be self-sufficient in energy. Thailand, on the other hand, is energy deficient and will increas- ingly rely on imports in spite of its oil, gas and lignite reserves. Cambodia is also dependent on imported energy. Hydropower resources in Lao PDR, Myanmar, Yunnan, and to a lesser extent Vietnam are abundant. High quality coal deposits occur in both Yunnan and Vietnam. Lignite deposits in Thailand and Lao PDR are unlikely to be exploited because of economic and environmen- Description tal concerns. Oil production within the GMS is limited. Figure 2.1: Past and projected electricity demand within the Greater Existing contracts and MOUs indicate that Thailand intends to Mekong Sub-Region. meet its energy deficit by importing hydropower from Lao PDR, rojectP Yunnan, Myanmar and possibly Cambodia; natural gas from Myanmar; and coal, oil and more gas from countries outside the Analysis of Alternatives GMS. Past and projected electricity demand for each of the GMS countries is given in Figure 2.1. However, as the economic slow- As a part of Project preparatory studies, and as a result of a World down in the region during 1997 illustrated, high levels of economic Bank request for independent verification that the Nam Theun 2 growth and corresponding high electricity demand are unlikely Project was indeed one of the most aractive options for power to be sustained throughout the entire demand forecast horizon, export from Lao PDR, GOLcommissioned a comprehensive Study and therefore periodic adjustments can be expected. Regionally, Thailand will remain by far the single largest market for electric- of Alternatives in 1997 (1998, updated in 2000 with the Hydro- ity trade. Assuming an aggressive demand side management pro- power Development Strategy Study). This study was updated in gramme, a reserve margin of 15% and the need to replace 3,000 late 2003. Findings of this new study will be incorporated into the MW of ageing thermal plants, Thailand would need, by the year final dra of the EAMP once they become available. The Study of 2010, some 15,000 MW of new capacity. Alternatives was conducted by Lahmeyer International and Wor- Power Generation Options in Thailand ley International Ltd in order to determine: The Thai hydropower industry has been established for many dec- · Whether electricity demand in Thailand, even with maximum ades, with the most suitable sites now fully developed. Remaining energy conservation, was strong and sufficiently robust to potential is limited to sites within national parks or on the Mekong absorb the commied power exports from Lao PDR (at that River and would be the subject of acute public opposition. Of time 3,000 MW by 2006, 3,300 MW by 2008, as agreed in 1998); other renewable energy resources, solar is currently only suitable · Whether the Project was sufficiently aractive to compete with for small applications, wind generation potential is limited by low other supply and demand side management options in Thai- and irregular wind speeds, and cogeneration from waste incinera- land; tors is only capable of making a modest contribution. For utility- · How the Project ranked among other candidate power export sized plants, the main fuel alternatives are imported and domestic natural gas, imported coal, imported heavy fuel oil and domestic schemes, considering technical, economic, financial, environ- lignite. mental and social criteria; The most suitable power producing options for Thailand from eco- · Whether the proposed configuration of the Project is optimal, nomic and socio-environmental perspectives are: i) gas-fired com- considering technical, environmental, social, economic, and bined cycle units for base and mid-load operation; ii) gas turbines financial risk factors; and and pumped storage plants to meet peak load and reserve; and iii) · Whether the Project should be recommended as one of the dual-fired steam power plants for base and mid-load operation. projects to cover Lao PDR's 3,000 MW power export commit- Of these, combined cycle and gas turbine plants provide the low- ment to Thailand. est cost generation. Although gas technologies have a clear cost advantage under present and expected cost structures, an analysis As part of the analysis three major workshops were organised. of gas consumption compared with available resources indicates The first discussed the study methodology, the second was held to that while in the short to medium term sufficient gas could be eliminate from the set of options those project alternatives which imported to cover the needs of the power system, gas imports in would be clearly inferior from a multi-criteria point of view, and the long-term will be insufficient, despite contracts with Malay- thelastwasheldtoselectthemostaractivedevelopmentproposal sia and Myanmar, and preliminary agreements with Indonesia. from the remaining set of options. The workshops were aended Imported coal is the next cheapest fuel, but such plants have con- by an average of 150 participants, including representatives from siderable environmental impacts, even with high quality coal and all ministries concerned, NGOs, donor and embassy representa- the latest emission control equipment. tives, and various experts. An alternative being promoted by the Thai Government is the use of lignite reserves and biomass in small-scale industry, as substi- Following is a summary of the findings of the Study of Alterna- tutes for petroleum-based fuels. Research in Thailand, as part of tives. the ASEAN-Australia Economic Co-operation Programme Energy 8 Analysis of Alternatives EAMP Main Text Table 2.1: Summary of ranking of hydropower projects for export Sum Project Technical Ecological Financial Economic Regional State of (W=5) (W=18) Social (W=18) (W=32) (W=7) Development Preparedness (Scores x (W=5) (W=15) Weights) Nam Theun 2 4 -9 -4 27 7 2 11 36 Nam Mo -1 -6 -2 19 4 1 6 22 Xe Katam -2 -7 -1 21 6 1 2 19 Xe Pian Xe Nam Noy 2 -8 -3 7 3 1 9 11 Nam Ngum 3 0 -7 1 5 0 1 11 10 Nam Ngum 2 ­ < cap.1 0 -7 1 5 0 1 8 8 Project Nam Ngiep 1 0 -7 0 9 1 1 3 7 Nam Ngum 2 ­ alone 2 4 -8 -7 8 1 0 9 7 Xe Kaman 1 0 -7 -2 5 1 1 8 6 Xe Pian Xe Nam Noy ­ low 3 2 -8 -3 0 3 1 9 4 Description Source: Lahmeyer and Worley, Hydropower Development Strategy Study, 2000 Note: 1. Capacity reduced from 615 to 446 MW; 2. Without the Nam Ngum 3 or Nam Ngum 5 projects; and 3. Low dam alternative. Phase II Project, reports that fluidised bed lignite combinations and livelihood were included within "difficulty", "infrastructure" are feasible for small-scale industrial use, but are not sufficient and "risk" categories for a social/community evaluation. for large-scale power generation. While existing older, large-scale Environmentally,theStudyofAlternativesidentifiedahighdegree power generation plants continue to rely on lignite fuel, the high of variability amongst the candidate IPPs: sulphur content will continue to be an environmental concern. · Flooding part of a recognised wildlife area for the Xe Kaman, Asaresultofapprehensionoverthelong-termviabilityofimported Nam Theun 1 and Nam Theun 2 Projects (part of a corridor fuel supplies and concern over negative environmental impacts, area); Thai policy is to prevent reliance on these energy sources and to · Creating a barrier to animal movements in a wildlife area for instead purchase electricity from neighbouring countries. the Nam Ou, Nam Theun 1 and Xe Kong 5 Projects; Finally, while Thailand does not plan to introduce nuclear power · Negative effects on downstream aquatic life due to anoxic in the short to medium term, it is keeping its options open for the water discharge from deep reservoirs for the Nam Tha, Nam long term. Depending on the availability of aractively priced Ou, Nam Theun 1, Nam Theun 3, Xe Kaman, Xe Kong 5, Xe electricity imports and the greenhouse gas emissions cap for Thai- Kong 4 and Nam Ngiep Projects; land, nuclear power may well become an alternative to coal-fired · Negative effects on downstream aquatic life due to daily peak- power plants. ing operation for the Nam Tha, Nam Ou, Nam Theun 1, Nam Theun 2 (in the configuration proposed at the time of the Power Generation Options in Lao PDR study), Nam Theun 3, Xe Kaman, Xe Kong 5, Xe Kong 4 and The only energy resources that could be exploited by Lao PDR Nam Ngiep Projects; and in the short term to meet its 3,300 MW commitment to Thailand · Air pollution for the Hongsa Lignite Project. are hydropower and lignite. Significant contributions cannot be The Study found that for several of the proposed IPPs a signifi- expected from any indigenous oil, gas, coal, uranium, solar, wind, cant reduction in their environmental impacts could be achieved geothermalorbiomass(waste)resourcesduetoalackofsignificant through the inclusion of additional design features, such as multi- resources or energy yields. Lao PDR, with its mountainous terrain ple level intakes and regulating ponds. and high rainfall, has abundant exploitable hydropower potential, Socially, the Study of Alternatives found that the scale of impacts estimated to be approximately 23,000 MW. To date, only three per- was directly related to the scale of the required reselement. All cent of this reserve has been developed. The lignite reserves are projects were evaluated to determine whether reselement could concentrated in the Hongsa field in Xayaboury Province. EGAT be reduced or eliminated. It was found however, that in most cases estimates the recoverable reserves of lignite to be approximately projects would need to be reduced to run-of-river status to achieve 530 million tons, sufficient to fuel a power plant for approximately a significant reduction in reselement as populations most com- 30 years. Tests indicate that while the average sulphur content is monly resided close to the river banks. low, a lignite-fired steam plant at Hongsa could still have diverse Where proposed IPPs were found to have significant negative and significant adverse environmental impacts. environmental and social impacts as well as high costs of genera- Review of Lao PDR Candidate Projects tion, it was recommended that the project not be considered for development. Comparison of Alternative Power Projects Following this initial assessment, the Hydropower Office of the MIH undertook a Hydropower Development Strategy Study to Nineteen candidate independent power projects (IPPs) were rank the remaining proposed IPPs according to: i) environmental examined in the Study of Alternatives. The analysis considered and social impacts; ii) technical status; iii) economic and financial technical, economic, financial, environmental and social criteria. issues; iv) regional development; and v) state of preparedness. The A number of important environmental and social elements were ranking of the projects against these criteria used a weighting sys- internalised within these broad categories. For instance, compen- tem developed through the stakeholder workshops. The weight- sation for impacts to terrestrial ecology through the provision of ing system was used in a weighted ranking process known as the conservation areas was included within a "potential benefit" cate- Multi-Objective Scenario Evaluation System (MOSES), adapted to gory.Additionally, a number of critical reselement issues, includ- the analysis by Lahmeyer International (2000). Table 2.1 presents ingethnicity,agriculture,landtenure,labourandgender,transport the ten highest ranked projects, their weighted component scores Analysis of Alternatives 9 EAMP Main Text Table 2.2: Technical data for selected Nam Theun 2 alternatives Reservoir Installed Energy Relative Relative Case Capacity Generation Project Cost Generation Max level (m) Area (km2) Live volume (MCM) (MW) (GWh/y) (%) Cost (%) Reference (NTPC) 538 450 3680 681 4885 100 100 Reservoir Case S (upstream dam) 532 251 1022 573 3130 90 143 Reservoir Case ROR 523 37 150 341 1665 79 236 (run-of-river) and overall score, and shows that the Nam Theun 2 Project was from Lao PDR. Once the Power Purchase Agreement (PPA) assessed as clearly the most aractive proposal. with EGAT is signed, the power market risk practically disap- Comparison of Multi-Project Scenarios for Power Export pears. · he Nam Theun 2 Project can easily compete with gas-fired Description Once the candidate power projects had been individually assessed combined cycle and coal plants, the two most economically and scored, they were arranged into various groups, which pro- aractive types of candidate power plants, for expansion of the vided viable scenarios for meeting GOL's power export commit- Thai electricity supply system. rojectP ment to Thailand. The criteria for these multi-project scenarios · The Nam Theun 2 Project was ranked second aer the Theun were: i) total installed capacity of approximately 3,000 MW; and Hinboun Hydropower Project in the Study ofAlternatives and ii) realistic expectation of commissioning by the year 2006. Not first in the Hydropower Development Strategy Study. The surprisingly, there were a number of combinations that could Theun Hinboun Project is now in operation. meet these criteria and altogether 36 multi-project scenarios were · Of the alternative configurations investigated for the Nam developed. Each scenario was analysed utilising the perform- Theun 2 Project, the most aractive was found to consist of: i) ance aributes of its component projects and compared using the a dam at Nakai; ii) a full supply level at El 538 m; iii) diversion MOSES methodology. This ensured that the most aractive multi- of water into the Xe Bang Fai; and iv) large installed capacity. project scenario was not simply the least-cost scenario, but the UnderthisconfigurationtheProjectwillprovidebothbaseload one with the best all-round performance. The final ranking placed and intermediate peaking capabilities to meet daily power those scenarios containing the Nam Theun 2 Project at the highest demands in Thailand. Risks associated with this configuration level. In addition, a full range of sensitivity studies were carried are considered manageable. out to test the robustness of this finding, including the application The Study of Alternatives recommended that the Nam Theun 2 of different weights to the assessment criteria. The results showed Project be one of the projects developed to meet Lao PDR's 3,300 that the Nam Theun 2 Project remained in all cases a robust part of MW power export commitment, with the provision that the the best power export scenarios. planned Environmental and Social Action Plans be fully imple- Findings of the Analysis of Alternatives mented. The Study of Alternatives, inclusive of the Hydropower Develop- No Project Scenario ment Study, found that: The Study of Alternative also assessed the trade-offs between the · The growth in demand for electricity in Thailand, even with best alternative scenario to the Project and implementation of the sluggish economic growth and vigorous energy conservation, Project. The tradeoffs for the "no-Project" scenario were i) US $320 is strong enough to accommodate 3,300 MW of power exports million less in income to GOL; ii) 2,420 fewer people to be reset- tled; iii) 286 km2 area flooded by reservoirs; iv) 138 km less river inundated. The Economic Impact Study determined that the Project would contribute to increasing the GDP of Lao PDR by a cumulative total of at least 3.2% over the life of the Project. This would reduce the number of persons falling below the poverty line by more than 13,000 (Louis Berger International, 1997), in addition to the expected improvement of livelihood standards among the reset- tled population, as indicated in the SDP. The Economic Impact Study (Louis Berger International, 1997) and Environmental and Social Management Plan (IUCN, 1998) concluded that the consequences of adopting the "no-Project" sce- nario would be: i) continued low GDP rates and high poverty lev- els; ii) forgone direct economic benefits including improvement of infrastructure, health services, etc.; and iii) accelerated exploitation of forests and forest biodiversity in the NNT NBCA. The economic assessment of Project impacts is currently being updated and the findings from the new analysis will be available for the final dra of the EAMP. The assessment will include an analysis of: i) costs and benefits of environmental impacts; ii) costs, Figure 2.2: Comparison of key parameters for selected Nam Theun 2 alter- benefits and cost-effectiveness of mitigation measures; and iii) natives ­ Reservoir Case ROR (front) & Reservoir Case S (back) impacts in terms of monetary values. 10 Analysis of Alternatives EAMP Main Text Project Description Figure 2.3: Nam Theun 2 Project schematic diagram Evaluation of Alternative Configurations Figure 2.2 provides a comparison of several other key parameters. Figure 2.2 indicates that by moving from a larger to a smaller reser- Alternative configurations, with reduced environmental and voir, the reservoir storage and the net present value reduce signifi- social impacts, were considered as a part of the Study of Alterna- cantly, whereas all other parameters reduce at a lesser rate. It has tives. Three parameters drive the overall environmental and social to be noted that the costs remain quite high for the Ban Thalang impacts: i) the size of the Nakai Reservoir; ii) the flow paern in (Reservoir Case S) and run-of-river options (Reservoir Case ROR), the Xe Bang Fai; and iii) the flow paern in the Nam Theun down- and that generation capacity decreases at a greater rate than costs. stream of the Nakai Dam. This indicates a steep rise in generation cost for a reduction in the Reduction in the Size of the Reservoir scale of the Project. In addition, reselement and length of river lost do not decrease at the same rate as the reservoir area. Given To reduce the size of the Nakai Reservoir, seven alternatives were the generating cost, it was found that the dam at Nakai, with a FSL considered: i) reduce the full supply level (Reservoir Case R); ii) at El 538 m was the most aractive alternative. move the Nakai Dam upstream to Ban Thalang (Reservoir Case S); iii) provide two reservoirs,onecreatedby adamnearBanThalang, Reducing the Effects of Discharges into the Xe and a lower reservoir created by a weir at the current proposed Bang Fai Nakai Dam site, pumping water from the lower reservoir into the upper reservoir (two-stage pump assisted scheme, Reservoir Case Several alternatives were considered to reduce the effects of dis- PS); iv) cut off part of the reservoir in the Nam Malou area and charges into the Xe Bang Fai: i) divert Power Station releases into pump water into the reservoir (Reservoir Case M); v) develop the the Nam Thon, a tributary of the Nam Hinboun, the laer being Project as a run-of-river scheme (Reservoir Case ROR); vi) develop already affected by incremental flows from the Theun Hinboun the Project as a pump storage scheme (Reservoir Case PSS); and Hydropower Project (Diversion Case H) ­ this option was rejected vii) provide upstream regulation at the Nam Theun tributaries because it presented no significant overall advantages and its cost (Reservoir Case U). was substantially higher; ii) deepen the river channel of the Xe The conventional pump storage plant (Reservoir Case PSS) was Bang Fai at strategic locations, by excavating rock ledges or other eliminated early because the Project is far from the main load cen- hydraulic controls, to reduce the effect of the increased discharge tres. Developing the Project as a hybrid project, with limited pump in the river; iii) shut down the Power Station when the Xe Bang Fai capacity,couldbearactive,dependingonthetariffsdefinedinthe floods to reduce the potential for increased flooding ­ this option PPA with EGAT. This would, however, have no environmental or has been incorporated into the Project; iv) provide regulation social benefits compared with the NTPC-proposed alternative. The upstream of where the Xe Bang Fai receives water from the Project, upstream regulation of the Nam Theun tributaries (Reservoir Case to reduce the natural flood hydrograph ­ suitable sites to impound U) alternative was found to be unacceptable as it would encroach upstream discharge were difficult to find due to a low and uniform into the NNT NBCA and would limit energy output unless major river gradient; v) increase the size of the regulating pond to enable reservoirs were constructed. This would be prohibitively expen- a more consistent discharge into the Xe Bang Fai during periods sive compared to the existing proposal. Analyses of the remaining when the Power Station is not operating ­ this option has been alternatives considered reservoir areas, volumes and energy gen- incorporated into the design of the Project; vi) divert the upper Xe eration costs. Overall, it was found that alternatives to the exist- Bang Fai; and vii) build a reservoir in the Nam Xe Noy tributary, ing Project design indicated only marginal differences from each which could then possibly be diverted to the Nam Phong river sys- other. tem for use in irrigation ­ this option proved to be economically Aer a public consultation workshop in 1999, it was decided very unaractive. that three reservoir alternatives would be considered in greater It was found that the use of a combination of a man-made channel detail: i) a dam at Kheng None (Nakai), with a full supply level at and the Nam Phit rather than the Nam Kathang to divert the water El 538 m and a reservoir area of 450 km2; ii) a dam at Ban Thalang, releases into the Xe Bang Fai is the alternative with the least social with a full supply level at El 532 m and a reservoir area of 251 km2; impacts, albeit at a higher economic cost, as the developer would and iii) a run-of-river option, with a full supply level at El 523 m need to construct a dedicated downstream channel. Discharge into and a reservoir area of 37 km2. Table 2.2 presents technical data for the Nam Kathang would likely impact 23 villages along the river each of these alternatives in terms of power generation cost, while and increase the number of people to be relocated. Evaluation of Alternative Configurations 11 EAMP Main Text Table 2.3: Lessons Learnt from other projects Lessons Learned How Incorporated into Project Design Consider project alternatives and design options Two comprehensive analyses of alternatives have been carried out (in 1999 and 2004) to consider different options for and consider environmental and social impacts power generation in Thailand as well as feasible hydropower development in Lao PDR for export of power to Thailand. in an integrated manner with the economic and These analyses of alternatives also looked at alternative configurations for the project site on the basis of social and envi- technical dimensions of the project. ronmental impacts (dam and reservoir size, the number of persons to be resettled) and technical and economic analysis. Carefully consider downstream environmental Downstream impacts in the Nam Theun, Nam Kading, Nam Kathang and Xe Bang Fai drainage areas have been identi- and social impacts, collect adequate baseline fied and quantified as part of the environmental impact assessment. data, identify those directly and indirectly Operational measures to reduce impacts include a provision in the PPA to suspend power generation during flood impacted by the project, and create adequate periods. Design features include an outlet structure, regulating pond, aeration devices and a downstream channel to mitigation and compensation programs cover- minimize erosion and improve water quality; and provision of predictable and consistent environmental flows. ing all project areas, with associated financial commitments, ahead of construction. Where feasible and economical, baseline data has been collected during the development of the EAMP. Long-term studies of fisheries impacts in the XBF, in the Nam Theun and upstream of the Nakai Dam will collect data throughout the construction period. A proactive mitigation and compensation programme is being developed with a dedicated budget and contingencies for the resettled population on the Nakai Plateau and in the downstream areas. Mitigation measures are expected to Description compensate fisheries impacts, loss of riverbank structures and gardens, and other effects. The specific level of funding is indicated in the SDP. Project financing includes contingency funds to cover cost over-runs, costs of unanticipated impacts, and failure to achieve agreed programme targets. rojectP Identify, prepare and implement development Formal and informal public briefings have taken place throughout the project preparation period. Major public con- and mitigation measures in consultation with sultations and workshops took place in 1997. New local consultations began in May 2004, followed by international project-affected people. Involve concerned civil workshops with civil society. The views expressed have been documented and are being taken into account in project society through participatory dialogue and be decision making. pro-active in response to issues raised; periodi- Sitting of resettlement villages has reflected the preference of affected people. Citizen concerns led to a change from re- cally disseminate project-related information. location on the Gnommalath plain to relocation on the Nakai Plateau and so that relocated villages are generally within "spirit village" areas. Village layout design has also been changed based on stated preferences. GoL and NTPC have provided considerable project information on their respective websites to engage civil society in dialogue on the Project. Informed and meaningful participation of project affected persons, and outreach to local populations, will continue throughout the remaining preparation and implementation periods. Clearly define the roles and responsibilities of Project includes establishment and strengthening of GoL institutions for conservation, social and environment oversight. all entities involved in implementation; address The project has been instrumental in establishing the NNT WMPA for watershed management, which will be funded by capacity gaps; develop adequate monitoring project revenues over a 30 year period. arrangements with task plans, budgets and Extensive monitoring, including GoL, NTPC, IFIs, IAG, DSRP and PoE, and independent monitors, is an integral part of sufficient long-term funding for all tasks to be the project design. certain that supervision continues long after project completion so that careful attention An independent professional firm will monitor key project issues for the lenders throughout construction and into the is paid during construction and operations to operational period, potentially until the commercial debt has been fully repaid, a period of about 17 years from financial ensure sound engineering and construction close. and proper compliance with environmental and social mitigation measures. Carefully scrutinize procurement aspects to Specialist consultants completed a review of the procurement process and the structure and cost of the head construction minimize the risk of cost and time overruns and contract (HCC) and subcontracts in April 2004. inferior long-term operational performance. Review concluded that there was adequate competition for two of the three civil works subcontracts and the two electro- Scrutinize contractor selection. mechanical subcontracts and that the agreed prices of all six contracts were generally consistent with, or better than, the prices which might have been expected from greater competition. Supervision of the entire procurement process by an independent engineering firm reporting to GoL and another independent engineering firm reporting directly to the lenders will help to ensure procurement transparency and efficient implementation. Thorough staff supervision by IFIs involved. Qualifications of HCC and subcontractors have been vetted. Financial institutions will need to approve qualifications of key operational personnel. Hydrological uncertainties have plagued past Project preparation has included detailed hydrological modeling, dam safety planning for a 1000 year flood, and pro- hydro projects in Lao PDR and elsewhere. tection of the watershed to prevent sedimentation. The PPA includes clauses to shelter NTPC from output losses due to XBF flooding and dry years. Active monitoring and timely warning of XBF flooding is an important feature of NT2 operations. Geological uncertainties, due both to the pau- Extensive, in-depth geological investigations have been carried out; geological risks in the near-vertical water conduits city of investigations undertaken and the rigors from the reservoir to the power house have been well catalogued and provisions made in the contract documents for of the terrain, have been the single largest cause accommodating design changes. of cost and time overruns in past projects. Power house design has been changed from under- to above-ground at some additional cost. Target pricing has been included in the HCC to shift a portion of the added cost to the project sponsors from the subcon- tractor in the event of unforeseen problems in the underground works. Where governance and expenditure manage- Proposed revenue management arrangements will target NT2 revenues to eligible priority programs in the GoL's NGPES. ment systems are weak, specific arrangements Parallel PEMSP is being designed to strengthen commitment to PEM reform program and improve implementation with may be needed to ensure that project revenues multi-donor financial support. are targeted and used transparently, while efforts continue to strengthen national systems. 12 Evaluation of Alternative Configurations EAMP Main Text season of 2004, when flow in the Nam Theun will be at its mini- mum. The riparian release will be aerated through cone valves. Cone valves have been used in various countries to enable an increaseinthedissolvedoxygenconcentrationofwaterdischarged from dams. The diversion of another stream into the Nam Theun immediately downstream from the Nakai Dam would increase the cost of construction and may not have a significant effect on the quality of discharge. Incorporation in the Project Design of lessons learned from other hydropower projects Project Figure 2.4: Dam and spillway cross-section The experience from two recent hydropower projects in Lao PDR, the Theun-Hinboun 210 MW trans-basin project and the Nam The Xe Bang Fai currently floods under natural conditions. At Leuk 60 MW trans-basin project, and from the Pak Mun 136 MW Description Mahaxai the average frequency of over-bank flows is approxi- run-of-river project in Thailand, but also the experience reflected mately 1 in 2.3 years and the lower Xe Bang Fai floods on almost in the report of the World Commission on Dams has been incorpo- an annual basis. Concerns have been raised that the Project will rated in the development of the Nam Theun 2 Project. increase the impact of these natural floods. A way to overcome Table 1 describes how these experiences and some of the key les- this problem would be to widen the channel of the Xe Bang Fai to sons learned have been taken into account in the design of the facilitate discharge. The cost of excavating the channel would be Project very high. Spoil area would need to be identified and plans would need to be developed for the relocation and compensation of the Lessons Learned from Other Hydropower affected people. A subsequent mitigation measure means that the additional water entering the Xe Bang Fai from the Project will not Projects increase the frequency or height of flooding due to an agreement The experience from two recent hydropower projects in Lao PDR, with EGAT that allows the Project to cease electricity generation, theTheun-Hinboun 210MWtrans-basinprojectandtheNamLeuk and therefore stop discharge, when the Xe Bang Fai is close to 60 MW trans-basin project, and from the Pak Mun 136 MW run-of- flooding. river project in Thailand, but also the experience reflected in the Reducing the Impacts in the Downstream Nam report of the World Commission on Dams has been incorporated in the development of the Nam Theun 2 Project. Table 2.3 describes Theun how these experiences and some of the key lessons learned have To reduce the impacts of a limited riparian release into the down- been taken into account in the design of the Project. stream Nam Theun, the options, which are not mutually exclusive, include: i) increase mandatory riparian releases; ii) aerate riparian Description of Project Infrastructure releases; and iii) partly divert a natural stream into the Nam Theun The Project will divert discharge stored on the Nakai Plateau from immediately downstream of the Nakai Dam. These alternatives the Nam Theun to the Xe Bang Fai, in doing so producing electric- were not discussed further in the Study of Alternatives. ity for delivery to EGAT and EDL, by utilising the difference in To assess the impact of the mandatory riparian releases and peri- elevations between the Nakai Plateau and the plain. To accomplish odic spills an environmental flow study is scheduled for the dry this, certain infrastructure will be constructed and will include: · Adam on the Nam Theun and necessary saddle dams to create the Nakai Reservoir; · StructurestodivertflowfromtheNakaiReservoirtothePower Station; · APower Station with the necessary facilities for converting the energy to electricity; · Downstream hydraulic control and conveyance structures to direct the diverted flows to the main channel of the Xe Bang Fai; · Transmission Lines to interconnect the Power Station switch- yards with the EGAT and EDL power transmission systems; and · Ancillary works to enable construction, operation and mainte- nance of the Project and to meet other obligations of NTPC. The infrastructure is described in more detail in the following sec- tions. Nakai Dam & Reservoir Nakai Dam The Nakai Reservoir will be formed by the construction of a grav- ity dam, located at a sandstone outcrop in a horseshoe-shaped bend of the Nam Theun at Keng None. The Nakai Dam will have Figure 2.5: Dam and spillway site a crest length of approximately 325 m and an approximate height Description of Project Infrastructure 13 EAMP Main Text Description rojectP Figure 2.6: Principle Project features 14 Description of Project Infrastructure EAMP Main Text Figure 2.7: Underground works Project of 48 m from the deepest foundation to its crest, which will not ing of the logs and debris. The boom will be located to prevent exceed El 541.5 m. The foundation will be grouted for seepage con- floating debris from fouling the Spillway and will include brightly trol. The Nakai Dam will be constructed with a drainage curtain coloured, visually prominent markers and appropriate warning and a drainage gallery. signs to warn small boats and other lake cra not to approach the Description Spillway structure.Across-section of the Nakai Dam and spillway is shown in Figure 2.4, while the site is shown in Figure 2.5. The spillway will have at least four radial gates that will be con- structed within the Nakai Dam section. A flap gate will be added Outlet Conduit for Riparian Release to the top of at least two of the gates to allow for discharge of small An outlet conduit will be provided next to the spillway to meet the floods without operating one of the large radial gates. The spill- downstream riparian release obligations. The riparian water will way chute will terminate in a hydraulic jump-stilling basin with be drawn from the reservoir through a variable-level intake struc- a concrete floor and retaining walls to reduce riverbed scour. The ture equipped with stoplogs, enabling the riparian release to be spillway and stilling basin will be capable of discharging the prob- drawn from the surface water of the reservoir down to 2 m below able maximum flood (PMF), calculated to be 15,984 m3/s, without MOL. A trash-rack will be located upstream of the stoplogs. The overtopping or endangering the safety of the Nakai Dam or the outlet conduit will be equipped with a cone valve permiing dis- saddle dams. Through the Nakai Reservoir, the flood peak will be charge of riparian flows without scour or damage to the channel of aenuated so that the peak passing over the spillway is less than the Nam Theun, and enabling aeration of the riparian flows. The the inflow peak. The spillway is also sized to work efficiently for outlet conduit will have the capacity to release a discharge equal anylesserfloods,andhydraulicmodeltestshaveshownthatitwill to 2 m3/s continuously during the entire year. In addition, it will be not experience damage with the passage of the PMF. An acoustic able to accommodate up to 10 m3/s on a continuous basis for short warning system will be installed on the Nakai Dam crest and at periods of time. the downstream end of the stilling basin to warn people when the Nakai Dam spillway will be opened. Ancillary Structures at the Nakai Dam To prevent problems from floating debris, a continuous floating Additional facilities at the Nakai Dam site will include: trash/log boom will be aached to the reservoir banks upstream · spillway control building to house all necessary controls and from the Nakai Dam. The boom will be positioned diagonally equipment, direct current and uninterrupted power supply across the reservoir to promote movement of logs and debris to systems, stores, workshops, control room and office facilities, the right bank. A concrete ramp will be provided to enable clear- and employee amenities for short-term accommodation; · Communications systems to the Power Station, intake struc- ture and hydrometric measuring stations; · A building for the diesel generators and fuel storage facilities; and · A1.8 m-high security fence, chain wire or equivalent to enclose the right and le abutment areas and the riparian release dis- charge channel area. Nakai Reservoir The full supply level for the Nakai Reservoir will be at El 538.0 m. At full supply level, the reservoir will have an area of approximately 450 km2 and will hold 3,910 million m3 of water. The minimum operating level will be at El 525.5 m. At this level the reservoir will have a surface area of approximately 82 km2. The reservoir volume between full supply level and minimum operat- ing level is approximately 3,530 million m3. Saddle Dams Fourteenearthembankmentsaddledamswillbeconstructedalong the escarpment side of the reservoir rim to enable storage to reach the full supply level. The crest levels of these saddle dams will be set at El 542.25 m. Where the lowest point of a saddle dam founda- tion is below El 539 m, the saddle dams will be earthfill or earth and rockfill structures with an impervious core. A foundation cut- Figure 2.8: Cross-section through the Power Station off of not less than 3 m depth will be used and the embankment Description of Project Infrastructure 15 EAMP Main Text Table 2.4: Turbine technical data Francis Turbines Pelton Wheels Vertical Shaft Number of turbines 4 (synchronous) 2 (synchronous) Maximum rotational speed 333 rpm 375 rpm Nominal capacity at generator terminal 251.3 MW 42.7 MW Bushbars between generating units and step-up transformer 4 MV 2 MV Transformer Single-phase, step-up to 500 kV Three-phase, step-up to 115 kV shoulders will be constructed with materials from excavations and Underground Works borrow areas. The headrace tunnel, pressure sha and pressure tunnel will con- Where the lowest point of a saddle dam foundation is at vey water from the intake structure at El 525.5 m to the Power Sta- El 539 m or higher, the saddle dam will be designed as a homoge- tion at El 170 m, providing a net head of 348 m. The underground Description neous embankment with cross-section geometry adjusted to the works will include a sub-horizontal headrace tunnel connected to materials selected for construction. The materials will be selected a pressure sha and then to a horizontal pressure tunnel. In sec- to achieve the required stability and permeability characteristics. tions of the tunnels where the surrounding rock cannot contain rojectP The upstream slope will be protected against erosion either by rip internal water pressure within the required margin of safety, or rap or suitable vegetation, with a flat gradient designed to limit where seepage losses might occur, the conduits will be steel lined. erosion and ensure the integrity of the water retaining structure. Otherwise, the remainder of the tunnels will be concrete lined. Grass or other suitable native vegetation will protect the down- A series of surge shas will be constructed to reduce pressure stream slope. Each of the saddle dams will be equipped with transients created in the tunnels during start-up and load-rejection instrumentation consistent with modern international dam safety operations. The surge shas will be concrete lined and will be of practice. varying diameters, increasing with height. The upper ends of the Flow Diversion shas will be at the ground surface. All parts of the headrace tun- nel, surge sha, pressure sha and pressure tunnel will be acces- Headrace Channel sible for inspection and maintenance. A 4.25 km-long headrace channel will be excavated in the Nakai Power Station Reservoir floor, approximately 35 km southeast of the Nakai Dam, to convey water to the intake structures when the reservoir is at Power Station & Generation Units minimum operating level. Materials excavated from the headrace The Power Station will be located approximately 10 km north of channel will be placed in approved spoil areas in the reservoir or Ban Gnommalat, at the foot of the Nakai Plateau escarpment. The used as landfill for roads, in saddle dam construction, or in the Power Station consists of a single, surface building to house six reselement areas. Also, a rock trap will be constructed in front of generating units, the administrative and operating offices, the the intake structure to retain any loose material that might be car- control room and facilities for the management and control of the ried into the intake and tunnels. Between the end of the headrace Project. Auxiliary infrastructure will include a workshop, garage, channel and the Nam Theun riverbed, a 5.1 km long corridor will standby diesel generating facilities and water treatment and stor- be leveled and cleared. The leveling and clearing of this area will minimise head loss between the water at the minimum operating level and the start of the headrace channel. A continuous floating trash/log boom will be constructed as close as possible to the entrance of the headrace channel to prevent float- ing debris from fouling the power conduit intake. The trash/log boom will also act as a floating marker and barrier to prevent small boats and other lake cra entering the headrace channel and the power conduit intake. Intake Structures The power conduit intake will be a concrete structure with four openings. Each opening will be equipped with trash racks and mechanised trash-cleaning rakes. The intake structure will be sup- plied with power from the Power Station. Additional back-up for operating the intake structure will be provided by a diesel genera- tor. Initially, the water passage will be horizontal and lead to a rec- tangular sectionwheretwogateswillbeplacedtocontrolflowinto the tunnels. The gates will consist of a fixed-wheel downstream service gate and an upstream guard gate, to be used for mainte- nance work and emergency access. The service gate will be used in conjunction with the guard gate to isolate the headrace tunnel from the Nakai Reservoir, allowing for de-watering and inspection of the tunnel and surge sha. Figure 2.9: Regulating Dam 16 Description of Project Infrastructure EAMP Main Text The turbines will include four Francis Turbine units, which will generate energy for delivery to EGAT and two Pelton Wheels, which will generate energy for delivery to EDL, the Power Station, and the operator's village (see Table 2.4 for details). All six generating units will be isolated and protected from the pressurised water supply by spherical valves within the Power Station. Dra tube gates will also permit the isolation of a unit for inspection and maintenance, allowing the other units to remain in service. Power supply to the Power Station, including the power generat- ing equipment, will be tapped from each of the Pelton unit's MV Project busbars through auxiliary transformers. Each of the transformers will be equipped with 22 kV busbars from which the Power Station auxiliaries are supplied through redundant MV/LV transformers. Description Emergency diesel generating units will be installed as back-up power sources for the main auxiliaries of the Power Station and the Project substation. The power transformers will be arranged on the upstream side of the Power Station, with the operating building and technical rooms being on the downstream side. The power transformers will be connected to the 500 kV substation by means of overhead lines and to the 115 kV substation by underground cables. SCADA System ASupervisory Control and DataAcquisition (SCADA) system will interface with a water management system to monitor, supervise and control the Power Station and switchyard. This system will enable analysis of the Nakai Reservoir, Power Station, generator, transformer and tailrace conditions. The system will enable check- ingagainstpredefinedlimitsand,ifnecessary,causechangestothe operation of the Project. All relevant information will be transmit- ted to EGAT's national and regional control centres and to NTPC's Vientiane office. The SCADA system will enable automatic opera- tion of the Project. Information provided to EGAT will enable them to integrate the energy into their power network, but not to control operations. Downstream Hydraulic Control & Conveyance Tailrace Channel, Regulating Pond & Regulating Dam Water discharged from the turbines will be conveyed through a concrete transition stilling structure into an excavated tailrace channel. The tailrace channel will convey the water to a regulating pond downstream from the Power Station and downstream from the confluence of the Nam Kathang Noi and Nam Kathang Gnai rivers. The maximum discharge from the Power Station into the regulating pond will be 330 m3/s. The regulating pond enables the Project to be operated as an intermediate peaking facility by regu- lating the downstream flows for environmental reasons. The purpose of the regulating pond is to limit water level fluctua- tion in the Xe Bang Fai, in particular during start-up, shut-down and load changing operations. It will be created by the construc- tion of an additional dam consisting of two contiguous concrete structures, one spilling into the Nam Kathang and the other into a downstream channel. An earth and rock-fill embankment will be Figure 2.10: Downstream channel constructed to complete the downstream closure of the regulating pond. The regulating pond will have an active storage volume of 8 million m3. Details of the regulating pond operations are pro- age facilities. Aminimum of 0.5 m freeboard above the level of the vided later in this chapter. 10,000-year flood will be provided for each of the structures. The regulating dam (Figure 2.9) will be equipped with gates for The main portion of the Power Station will be approximately irrigation intakes and outlet channels. The capacity of the irriga- 130 m long and 35 m wide. The location of the Power Station rela- tion channel will be approximately 5 m3/s when the regulating tive to the underground works is shown in Figure 2.7 and a cross- pond is at minimum operating level. A trash/log boom across the section through the Power Station is presented in Figure 2.8 regulating dam's discharge intake area will be provided to trap Description of Project Infrastructure 17 EAMP Main Text Figure 2.11: Nam Gnom siphon Description rojectP Figure 2.12: Confluence with Xe Bang Fai floating debris, to provide signs to warn people not to approach, and to stop small boats from approaching the discharge gates. An acoustic warning system will be installed on the regulating dam crest and at the downstream end of the stilling basin, as well as along a portion of the Nam Kathang downstream of the regulating dam to warn people, upstream or downstream of the spillway, of the imminent opening of the spillway gates. Nam Kathang Release Water will be released from the regulating pond into the Nam Kathang below the regulating dam at a rate equivalent to the natu- ral inflows of the Nam Kathang Gnai and Nam Kathang Noi. The arrangement of the Nam Kathang riparian release structure and the spillway stilling basin and end-sill will be designed to provide aeration of the discharge. Downstream Channel A27 km long, excavated channel will direct flow from the regulat- ing pond to the Xe Bang Fai near the town of Mahaxai. The maxi- mum capacity of the channel will be 333 m3/s, plus the discharge from the surrounding drainage, equivalent to a two-year flood event. The downstream channel will accommodate discharges from the Power Station, flow variations, local drainage and flood Figure 2.13: Aeration weir inflows without damage to the channel invert, banks or ancillary structures. The downstream channel is depicted in Figure 2.10. The first 8.5 km of the channel will be lined with concrete, rock an inverted siphon will take the downstream channel under the gabions or rock, with a maximum boom width of approximately Nam Gnom (Figure 2.11). The first section of the downstream 20 m. This section of the channel will be designed for an average velocity of 4 m/s. Normal flow levels will be sufficiently above channel ends at the aeration weir. natural ground to permit the installation of gravity-fed irrigation Downstream of the aeration weir, the channel will have an invert release points along the course of the channel.At Ban Gnommalat, width of 21.5 m, flat 3:1 baers in natural soil with rock protection 18 Description of Project Infrastructure EAMP Main Text Runoff from local adjacent catchments will be managed or regu- lated to ensure that the nominal release of 330 m3/s can continue for all events up to and including the 10-year average flood. The downstream channel will be designed for withstanding overtop- ping and/or inundation from local catchment flood flows up to the 1000-year average flood event. The unlined channel will be designed to enable runoff to enter the channel, or drain to natural channels. The confluence of the downstream channel with the Xe Bang Fai is depicted in Figure 2.12. Aeration Weir To improve the concentration of dissolved oxygen and to reduce Project the concentration of methane and hydrogen sulphide in the water released through the Power Station, a U-shaped aeration weir will be installed in the downstream channel (Figure 2.13). It will allow Description water to spill over the structure. Transmission Substations Figure 2.14: 115 kV Transmission Line schematic The Project will include a 500/115 kV substation as well as a 115/22 kV substation, both of which will be constructed adjacent to the Power Station. These substations will supply energy to EGAT (500kV) and EDL (115kV to Thakhek and 22kV locally). Power supply for the substation auxiliaries will be tapped from two redundant auxiliary transformers located in the project substa- tion. Back-up electricity will be derived from the Power Station's standby diesel generating units. Transmission Lines Electricity generated for EGAT will be delivered at the Lao-Thai border north of the town of Savannakhet, via a 138 km-long, dou- ble circuit 500 kV Transmission Line. To feed the electricity into the EGAT system, an additional double circuit 500 kV Transmission Line, approximately 160 km in length, will be constructed from the Lao­Thai border to a new sub-station at Roi Et, Thailand. The 500 kV Transmission Line within Lao PDR will be designed so that any future link to a switching station near Savannakhet can be con- structed without interrupting the delivery of electricity to EGAT. The normal operating configuration of the 500 kV Transmission Figure 2.15: Ban Itak crossing Line shall be two circuits in service, irrespective of the number of generating units synchronised to the EGAT system. at a few critical points. The maximum regulating pond discharges Most of the energy for EDL will be transferred from the Project in this section of the channel will be contained either below natural substation via a 70 km 115 kV Transmission Line to a 115/22 kV surface level or within levee banks, as required by the local terrain. substation transformer in Thakhek. The Project 115kV double cir- It will allow surface run-off and floodwaters from local adjacent cuit Transnission Line will end at Mahaxai, where a station will catchmentstodrainintothechannel.Thedownstreamchannelwill enable the transfer of energy to the Sepon Project and to Thakhek. then pass through a karst outcrop, via a tunnel. Upstream of this The development of these lines from Mahaxai to Thakhek is the tunnel, an emergency spillway will be constructed with a capacity of not less than 100 m3/s. This spillway will protect the channel responsibility of EDL. EDL will also be able to off-take approxi- when discharge exceeds the design discharge, inclusive of flood mately 20 MW of energy at the Power Station substation via exist- inflow from the local drainage area. Discharge from the emergency ing and Project-built 22 kV Transmission Lines (Figure 2.14). spillway will flow into the Nam Phit, facilitating the discharge of The Transmission Line towers will be constructed as self-support- water into the downstream channel. The tunnel portals shall be ing steel laice structures. The normal spacing between consecu- provided with walkways to enable crossing of the downstream tive towers will be approximately 450 m. The footprint of the tow- channel and a continuous floating trach/log boom at the upstream ers will be approximately 10 m by 10 m. The precise route of the portal will prevent floating debris entering the tunnel and stop Transmission Line is still being defined, but will avoid houses or boats approaching. Downstream from the tunnel, the downstream selements and, where practical, agricultural areas. Minor com- channel will be designed generally to follow the Nam Phit. It will pensation may be required as a result of the construction of access have baers of 3:1 in the natural soils of the area, a flat baer which roads and the towers themselves. is designed to be non-eroding. Average speeds in the total unlined section will reach 2.3 m/s and the levee banks will have a height of Mekong crossing approximately 2 m. The downstream channel starts at El 166.97 m Two towers will be placed in the Mekong River channel, one near and ends at El 142.06 m, with its gradient varying according to the the Lao side and the other near the Thai side of the river. Construc- different sections. tion of the foundations is expected to occur during the dry season, Description of Project Infrastructure 19 EAMP Main Text Description rojectP Figure 2.16: Road construction and improvements 20 Description of Project Infrastructure EAMP Main Text Project Description Figure 2.17: Location of quarries and spoil disposal areas Description of Project Infrastructure 21 EAMP Main Text when the Mekong River is at its lowest, to limit potential adverse Existing roads will be upgraded and new roads will be constructed impacts on the river. as necessary to enable access to the reselement villages. New Ancillary Works tracks to the reselement houses and farm lots will also be con- structed. These roads will have a maximum width of 3 m, within Roads & Bridges an 8 m wide right of way. Forest roads will also be constructed to assist with the management of the community forest areas. As part of the Project, NTPC will construct approximately 56 km of In addition to the three road bridges, eight local community new roads and upgrade over 100 km of existing roads. bridges will be constructed across the downstream channel. Asso- Between Thakhek and Ban Gnommalat, the existing Roads 12 ciated access roads will be constructed at various locations based and 8B will be upgraded to provide a safe two-lane road. Existing on input from local residents and on the locations of significant bridges will be improved or rebuilt as needed to ensure they are existing tracks. Determination of the exact locations of the bridges in a safe and serviceable condition. Two additional bridges will be will be based on consultations with local residents. The bridges constructed where Road 12 and Road 8B cross the downstream will be of two types: channel, near the intersection of Roads 12 and 8B, and at the Ban · Five pathway bridges will be constructed. Each of these Itak crossing (Figure 2.15), respectively. Another new bridge will Description bridges will support two-tonne loads and will be dimensioned be constructed where the road to Ban Thathot crosses the down- to accommodate small farm tractors up to 1.75 m wide. stream channel. The upgrading of these roads will facilitate the · Threebridgeswillbeconstructedwherethedownstreamchan- construction and operation of the Project. nel crosses existing local public roads. Each of these bridges rojectP Between Ban Gnommalat and Ban Oudomsouk, the existing road will be able to support four-tonne loads and will be dimen- will be significantly upgraded. In the section leading from Ban sioned to accommodate vehicles up to 2.5 m wide. Gnommalat to the Nam Kathang, the road will be raised above flood levels and drainage works will be installed. From the Nam A 4 m-wide gravelled access track will be constructed along the full length of one edge of the downstream channel for inspection Kathang to Ban Oudomsouk, earthworks and drainage improve- and maintenance. ments will be constructed to ensure a stable and safe all-season road. In addition, an access road will be built from Ban Oudom- The roads to be constructed and upgraded by NTPC as part of the souk to the reselement community southeast of Ban Oudomsouk, Project are shown in Figure 2.16. partly through the rehabilitation of an existing road and partly Residence Nam Theun through new construction. A new road will be constructed to replace the section of Road 8B The Project will require an operator's village, Residence Nam Theun, to be established for permanent employees.Approximately northwest of Ban Oudomsouk, as this part of the road will be inun- 150 permanent employees will be housed here to enable the ongo- dated by the reservoir. The new road will follow the southern rim ing operation and maintenance of the facility. The new village will of the Nakai Plateau from Ban Oudomsouk to Ban Thalang and be constructed near the regulating dam. Apart from housing, the cross the Nam Theun via a new bridge. The new road will join the village will include shops, a post office, a telecommunications cen- existing Road 8B at Ban Nam Nian. tre, water and sewerage treatment plants, fire fighting units, an Anew access road will be constructed to enable travel to the Nakai emer-gency power supply, a helipad, recreational and leisure facil- Dam on the Nam Theun. The road will be constructed from Road ities, a health dispensary and a school. The village will be acces- 8B, near Ban Phonkeo. sible by a two-way, paved road. Table 2.5: Tentative schedule for Project construction MONTH DESCRIPTION 1-12 13-24 25-36 37-48 49-54 PPA EXECUTION FINANCIAL CLOSE DATA Construction Schedule of the EGAT Transmission Facilities Anticipated Design & Preparatory Works Project Detailed Design Nakai Dam Construction Intake & Tunnel Construction & Testing Power House & Transformer Civil Works 500 kV & 115 kV Substations Generating Units Erection & Concreting Units Mechanical & Electrical Test Unit Commissioning Ready Date SCRD 1,2,3,4 Regulating Dam Downstream Channel 500 kV Transmission Line Design SGIRD SGCRD 500 kV Transmission Line Construction SED 500 kV Transmission Line Commissioning SCHEDULED COMMERCIAL OPERATION SCOD 22 Description of Project Infrastructure EAMP Main Text Project Description Figure 2.18: Location of construction work camps and work areas Description of Project Infrastructure 23 EAMP Main Text Materials Sources There are two main limestone quarries for aggregate production for concrete and other construction needs. The first is located at Phou Phako. It will provide materials for civil works on the Pla- teau. The second source is located at Pha Thung, near the down- stream channel, and will supply material for the Power Station and downstream civil works. Laboratory results from both sites indi- cate acceptable mechanical properties and the materials are classi- fied as non-alkali reactive. In addition to these two major sources, several smaller sources have been identified, including an area just downstream from the Nakai Dam site from where sandstone can be quarried, and several borrow sites along Road 12. Potential sand sources are located near the construction areas. Spoil Disposal Areas Description A number of potential spoil disposal sites have been identified Figure 2.19: Nakai Reservoir operation simulation for placing excavated materials not utilised in the construction "Average hydrological year": This is the year which had a total runoff most closely of the Project. Spoil materials will be generated mainly from the equal to the average for the entire extended series. The year selected is 1990. "Wet hydrological year": This is the year which had the least total runoff for the entire rojectP excavation of the downstream channel, and to a lesser extend by the headrace channel and other construction activities. Spoil, extended series. The year is 1998. whenever possible, will be used to construct roads, saddle dams, "Dry weekly hydrological year": This is an artificial hydrological year, created by select- for landscaping, and for fill in the reselement areas. All spoil ing for each week of the year, the driest week over the extended period disposal areas and other areas disturbed during the construction period will be landscaped to restore drainage, encourage the re- are scheduled to be completed within 38 months. The mechanical establishment of vegetation, stabilise slopes and minimise visual and electrical installations will proceed as soon as possible in con- impact once construction is complete. The locations of the spoil junction with the completion of the civil works. disposal areas are indicated in Figure 2.17. ThetotalconstructionphasefortheProject,includingcommission- Construction Work Camps ing, is estimated to be 54 months from Financial Close. Commis- Four zones have been identified for the development of construc- sioning, testing and acceptance under the EGAT PPA are sched- tion work camps within the Project area. They will accommodate a uled to commence 46.5 months aer Financial Close. maximumconstructionworkerpopulationofapproximately4,000. Construction Contracts These zones, from north to south, are i) Nakai Dam area construc- tion camp; ii) Nakai work camp zone; iii) Power Station work camp Given the scale of the Project, the construction contracts will con- zone; and iv) downstream work camp zone.Additional zones have sist of five principal sub-contracts and one overriding Head Con- been identified in the vicinity of each major work site, outside and struction Contract (HCC). The HCC is to be undertaken by EDF. separate from the formal construction camps. These zones have The Head Contractor is responsible for ensuring the timely con- been selected to accommodate the businesses and families that will struction of the Project and is liable for liquidated damages for any likely become established in the neighbourhood of the construc- delays in completing the Project. The five principal sub-contracts tion camps. To accommodate these businesses, it was assumed that are divided into two electromechanical packages (EM1 and EM2) land for four times the number of workers will be required at each and three civil works contracts (CW1, CW2 and CW3). of the work sites. Figure 2.17 indicates the locations of the con- EM1 includes the Power Station generating units and associated struction work camps in relation to significant construction areas. equipment, including the four Francis generating units, two Pel- ton generating units, mechanical auxiliaries, electrical auxiliaries, Project Construction, Operation & 500/115/22 kV substation equipment, SCADAequipment, telecom- Decommissioning munications and workshop equipment and service facilities. EM2 includes the 500 kV double circuit, 138 km Transmission Line from the Project to the international border and the 115 kV single circuit Construction 77 km Transmission Line from the Project to Mahaxai. Construction Schedule CW1 includes the upstream works including the Nakai Dam, saddle dams, spillway, radial gates, road rehabilitation and new Some preliminary works will start before Financial Close. They works, bridges, the operator's village and associated infrastruc- include, among other activities, the construction of the access road ture. CW2 includes the Power Station, intake structure and gates, from Road 8B to the site of the Nakai Dam and the upgrading of underground works, and switchyard platforms. CW3 comprises existing roads to provide access to the construction camps and the tailrace channel, regulating pond and dam, gates and down- work sites. Further roadwork, e.g. to Residence Nam Theun, exca- stream channel. EM1, EM2, CW2 and CW3 will be open to Inter- vation of the Power Station site, access and drainage tunnels, and national Competitive Bidding. ITD will be responsible for CW1. To campsite construction may commence at approximately the same ensure that the price of CW1 is reflective of international market time as Financial Close. standards, the contract price tendered by ITD will be referenced to The construction of the Nakai Dam, saddle dams, headrace chan- international standards and prices. nel, inlet works, tunnels and shas, power house, tailrace channel, regulating dam, downstream channel, Transmission Lines, sub- Project Cost stations, plant, roads and operator's village will be initiated aer The total cost of constructing the Project is estimated to be approxi- Financial Close. A tentative schedule for the Project's construction mately US $1.3 billion. Three basic funds will be used throughout is presented in Table 2.5. The Nakai Dam and appurtenant features the construction period. The base finance will include the main 24 Project Construction, Operation & Decommissioning EAMP Main Text Operation of the Nakai Dam Operation of the Nakai Dam will involve the riparian release of 2 m3/s into the Nam Theun downstream of the Nakai Dam, meas- ured as an average on a weekly basis. In the reservoir operations simulation model, spill from the Nakai Dam to the Nam Theun occurred in 18 of the 47 years for which the simulation was run. Maximum spill to the Nam Theun is expected to be approximately 1,280 m3/s, with the average spill being approximately 156 m3/s. Large spills will occur when inflow to the reservoir is much higher than the normal inflow. These results are based on an extended hy- drologic record and may or may not represent the actual inflows Project to the Nakai Reservoir. Operation of the Nakai Reservoir Description The operation of the Nakai Reservoir is based on a maximum res- ervoir elevation of El 538 m. The minimum operating level is at Figure 2.20: Regulating Pond volume (million m3) for a 50% secondary El 525.5 m. Drawdown of the reservoir will normally occur during energy production scenario the dry season, with filling occurring during the wet season. Dur- ing periods of high inflow the maximum reservoir elevation could be achieved, resulting in water being discharged through the gates of the Nakai Dam. However, based on the reservoir simulation conducted for the Project, this is only expected to occur approxi- mately once every 2.6 years. Figure 2.19 provides the basic results of the reservoir operation simulation based on an extended 47 year hydrologic record. The hydrologic record was developed from a 13-year record of dis- charge at Ban Thalang, extended downstream to the Nakai Dam site. The figure presents an average of operation of the Nakai Res- ervoir, along with maximum and minimum conditions. As can be observed in the figure, when total yearly inflow is high, the reser- voir will fill and some water will be spilled into the Nam Theun downstream of the Nakai Dam. When total yearly inflow is low, filling of the reservoir cannot be achieved. On average, the maxi- mum reservoir elevation will be at about El 536.5 m and the mini- mum level will be at approximately El 526.5 m. Figure 2.21: Discharge (m3/s) from the Power Station (green) & Regulating The weekly results presented in the figure are derived from a Dam (orange) for a 50% secondary energy production scenario simulation of reservoir operations using a reservoir operations program. The operations program assumed an installed capacity of 1,070 MW and the results are considered indicative of how the construction contracts and other costs associated with managing reservoir and Power Station will operate. As 93% of the estimated the construction effort. Contingent financing will be required dur- river inflow is diverted for power generation, lile additional ing the construction period to handle debt service costs and inter- power can be obtained. The reservoir operations model assumed nal administrative costs. Additionally, money will be allocated for supplying 100% primary energy for 16 hours each day for six days general contingency considerations including problems arising a week. Secondary power may be produced at any time. from the construction contracts. Operation of the Power Station Operation The Power Station will have a generating capacity of 1,080 MW (net 1,070 MW). Normally, the Francis turbines will be operated to TheProjectwillbeoperatedbyNTPC.Theoperationwillbehighly provide baseload energy for delivery to Thailand. The normal dis- automated, with an estimated 150 people employed to operate and charge through the turbines will be approximately 250 m3/s. How- maintain the Project. ever, this will vary depending upon the demand in Thailand. The Pelton Wheels will produce electricity for use at the Power Station The Project will be operated in accordance with EGAT's National and for delivery to EDL, either via the 115kV Transmission Line or Control Centre (NCC). Upon a request from the NCC, the opera- the 22kV supply at the Power Station. At its maximum discharge, tor will start or stop individual units and will carry out substa- a total of 330 m3/s may be diverted through the Power Station. tion switching actions as appropriate. Upon receiving a dispatch During the initial years of operation, the Project will monitor the instruction from the NCC, the SCADA system will check whether potential for causing additional flooding along the Xe Bang Fai.At such dispatch instructions are consistent with the unit capacity Mahaxai, flooding occurs when the flow of the Xe Bang Fai reaches ranges based on the water level in the reservoir and the number of 2,270 m3/s. As flow begins to approach this level the Power Station will be shut down to prevent additional flooding that would result generating units available. Whenever the dispatch instructions are from the additional discharge. out of such ranges, the SCADAsystem will warn the NCC and the Different operating scenarios were used in the operations model operator will recommend a corrected dispatch instruction so that to determine the feasibility of the Project. One of the scenarios, it complies with the available generating capacity. presented in Figure 2.20, involves production of 50% secondary Project Construction, Operation & Decommissioning 25 EAMP Main Text and closure of the underground works. The ability to operate the Nakai Dam would be eliminated and adjustments made to enable theflowoftheNamTheuntocontinueasbeforeconstructionofthe Project. For this to occur it would be necessary to open and modify the riparian outlet and open or remove the spillway radial gates to allow the water to flow through the Nakai Dam in an unregu- lated manner. This would also most likely mean that the Nakai Reservoir would remain at approximately El 527 m throughout the year. Similar adjustments would have to be made for the regulat- ing dam. In general, decommissioning of a power project entails nearly as much planning as the construction of the project in the first place. Considerable consultation would be required, not only with the residents of the Nakai Plateau, but also with the residents along the Xe Bang Fai. It could be assumed that prior to decommission- Description ing the Nam Theun 2 Project, the Theun Hinboun Hydropower Project would also be decommissioned. This could result in the Nam Theun being returned to a state that would be similar to its condition prior to the construction of both dams. rojectP Figure 2.22: Nam Theun 2 catchment area & Xe Bang Fai basin Location & Study Area energy along with the baseload operation. As shown in the figure, The River Basins intermediate peaking energy will be produced for up to 16 hours Both the Nam Theun and the Xe Bang Fai basins (Figure 2.22) will per day and no energy will be generated on Sundays. The lack of be impacted by the construction and operation of the Project. Sunday generation will have some consequences for the operation of the regulating pond and the discharge delivered to the Xe Bang Nam Theun Basin Fai. The Nam Theun originates at Phou Laoko in the Annamite Moun- Operation of the Regulating Pond tains, at an elevation of about 2,286 m above sea level. From that point the river runs south to the Nakai Plateau at an elevation of The purpose of the regulating pond is to dampen variations in about El 525 m. Three major tributaries of the Nam Theun on the water discharges to the Xe Bang Fai. In general, discharge from Nakai Plateau are the Nam On (including the Nam Mon and the the regulating pond will be maintained at a constant basis, except Nam Yang), the Nam Noy (including the Nam Pheo) and the Nam on Sundays, when no energy is generated from the Power Sta- Xot (including the Nam Mon). These mountainous tributaries tion. On average, discharge from the regulating pond will be have carved the landscape into deep V-shaped valleys separated 240 m3/s. However, at times, discharge from the regulating dam by steep ridges. The mountains that form the watershed are mostly may be increased to 330 m3/s, depending upon the level of water forested except for isolated areas that support dense undergrowth in the regulating pond and the quantity of electricity being dis- vegetation. Since most of the catchment is remote, sparsely popu- patched to EGAT. As shown in Figure 2.21, Power Station dis- lated and difficult to access, a large portion of the forest remains charge to the regulating pond will fluctuate considerably from day intact. The NNT NBCA is recognised internationally as an impor- to day. The results shown in the figure relate to the 50% secondary tant area of tropical and subtropical biological diversity. The tradi- energy generation scenario described in the preceding section. On tional livelihoods of communities living in the watershed include Sundays the amount of water in the regulating pond will be drawn shiing cultivation, livestock production, hunting, fishing and down to the minimum level. The amount of water discharged from gathering of forest plant products. the regulating pond to the downstream channel may be reduced The Nam Theun meanders along the relatively flat Nakai Plateau to the guarantee minimum of approximately 30 m3/s. Regulating to the proposed dam site.Agricultural and forestry activities along pond operations will also limit the rate of increase and decrease in the river have contributed to the reduction of wildlife populations discharge being released into the downstream channel. The maxi- along the river. The Plateau's population relies on wet season rice mum rate for increasing and decreasing discharge in the down- farming during the rainy season and fishing and hunting activities stream channel is 20 m3/s/hour and 30 m3/s/hour respectively. The during the dry season. Very few families are able to produce sur- regulating dam will also release water into the Nam Kathang, at plus rice and most grow enough to provide household rice for only a rate equivalent to the discharge in the Nam Kathang Gnai and about two-thirds of the year. These issues are of critical importance Nam Kathang Noi above the regulating pond. in developing an effective reselement plan. Project Decommissioning Just downstream of the proposed dam site, the river leaves the flat alluvial section of the Plateau and winds through heavily forested Depending upon the length of service, the decommissioning of a hills in a succession of relatively slow flowing pools and rapids. A hydropower project may require environmental and social assess- few tributaries enter the Nam Theun from the eastern and north- ments. It could involve removal of the Nakai Dam and Power ern drainages. The Nam Theun gorge downstream of Ban Thalang Station and returning the river to its original situation. However, is a wild area of open, dry evergreen forest that the river bisects. depending upon the length of service, the reservoir may have Here the river dramatically changes character from the slow, established a new valuable ecosystem also beneficial to residents 75 m-wide river of the Plateau to a 40 m-wide series of alternating of the area. In this instance, removal of the civil works could cre- rapids and pools that cuts through the sandstone and mudstone ate a considerable negative effect. Decommissioning of the Project rock. This stretch of the river supports no permanent selements. could therefore merely involve the removal of the Power Station The next selements are at the confluence with the Nam Ngoy. 26 Location & Study Area EAMP Main Text Project Description Figure 2.23: Location & study area Location & Study Area 27 EAMP Main Text No cultivation has been observed between the Nakai Dam and the follow relatively flat gradients out of the catchment area, this Zone headwater of the Theun-Hinboun Project, though it has been noted includes the channels of streams and rivers that will be affected that people living along Road 8B in Khamkeut District do fish in by inundation of the reservoir. The reservoir has an area of 450 the Nam Theun downstream of the Nakai Dam. km2 at full supply level and the islands that will be formed in the Aer the Theun-Hinboun Dam, the Nam Theun cascades down an reservoir area. The impacts aributable to the Project in this zone escarpment through a gorge to a relatively flat area. It then flows through another gorge. From this point the Nam Theun is known are primarily caused by the impoundment of the reservoir on the as the Nam Kading, which reaches the Mekong River approxi- Nakai Plateau and include inundation of land, water quality in the mately 96 km downstream. reservoir, plants and animals of the reservoir area, and human set- tlements.Approximately 1,030 households and 5,684 people reside Xe Bang Fai Basin intheinundationareaandwillrequirerelocation.Thereselement The Xe Bang Fai catchment has a total area of 9,562 km2 and drains programs for these people are detailed in the RAP. The people will from the ridge of the Louang mountain chain along the Vietnam- also be affected to some degree by construction activities, which ese border, where the highest peak is just under El 1,650 m. A include the building of the Nakai Dam, headrace channel, saddle number of tributaries discharge to the Xe Bang Fai, particularly dams and intake structure. Description in the upper reaches of the river. The headwaters of the catch- ment are characterised by steep ridges and deeply incised gullies. Zone 2: Protected Area & Corridor Areas In the valleys upstream of Mahaxai, the river channel begins to meander through sandy banks. This meandering is primarily due The NNT NBCA is approximately 3,500 km2 in area. This repre- rojectP to the low gradient of the channel from Mahaxai to the Mekong sents approximately 88% of the Nam Theun catchment for the res- River. Downstream of Mahaxai, the Xe Bang Fai flows through a ervoir. Approximately 5,800 people live within the NNT NBCA. well-defined channel that is characterised by extensive meanders These people are not directly affected by the Project but can poten- until it flows through the Sayphou Xoy Range. This gorge is con- tially affect its performance. A significant increase in erosion from sidered a hydraulic control and can cause backwater upstream of the gorge during flood events. The Xe Bang Fai is joined here by the NNT NBCA through poor land use practices would result in its major tributary, the Nam Xe Noy. The Xe Bang Fai catchment increased sedimentation in the Nakai Reservoir and potentially a downstream of the bridge on Highway 13 is called the Xe Bang Fai shortening of its life and efficiency, as discussed in Chapter 3. Plains. The plains are about 15 km wide, bounded by the Mekong The study area also includes two corridor areas (approximately River to the west and upland forest to the east. They consist of low 770 km2) that connect the NNT NBCA with the Phu Hin Poun lying ground, separated by some slightly higher areas that drain NBCA to the west (the limestone karst area) and the NNT NBCA into the Xe Bang Fai. The depth of the river during the dry season varies from several metres to just a few centimetres on some sand with the Hin Nam No NBCA to the south. The boundaries of the bars. When the water surface in the Xe Bang Fai exceeds a cer- NNT, the Phu Hin Poun and the Hin Nam No NBCAs were estab- tain level, backwater from high Mekong River discharges causes lished in 1993 by PM Decree 193. The management of the NNT flow in the river channel to be reversed. The banks are overtopped NBCA will focus on the conservation of the internationally recog- and general flooding of up to 1.5 metres occurs over the low-lying nised biological diversity. Plans for the management and conser- areas. Except for the villages along a small band of Highway 13 vation of the NNT NBCA and corridor areas can be found in the and Road 12, the area is remote and difficult to access, especially SEMFOP. in the wet season. Overall Study Area Zone 3: Proposed Resettlement Area The study area includes areas that will be affected, though possi- Aer consultation with the impacted population, an area along bly not directly impacted by the Project. The environmental study the southern rim of the Nakai Plateau has been delineated as the areas include the immediate area around the Project, the Nam area where residents of the reservoir areas will be relocated. The Theun downstream from the Nakai Dam, the Xe Bang Fai, and the area consists of approximately 208 km2 and is located along the Mekong River between the Nam Kading and the Xe Bang Fai. The southern rim of the Plateau escarpment. The region is vegetated north-south dimension of the environmental study area is 240 km with mixed broadleaf and coniferous forest, dry evergreen for- in length and extends from the Mekong River confluence of the est, unstocked forest and agricultural areas. Drainage from the Nam Kading to the point on the Mekong River where the power area flows into the Nam Theun. At its northern end, the resele- Transmission Line crosses into Thailand. The east-west extent is 110 km from the Lao-Vietnamese border to the Lao-Thai border. ment area is immediately adjacent to the Nakai Nam Theun ­ Phu The area incorporates approximately 26,400 km2. Within the study Hin Poun Corridor. The host population of Zone 3 are primarily area, as shown on Figure 2.23, the potentially impacted areas are in the villages of Nakai Tai and Nakai Neua. The District head- described along river boundaries and various types of land use quarters, Ban Oudomsouk, is also located in this area. Currently within those areas. Figure 2.23 identifies all of the study areas and there are approximately 520 households in this study area. Some the following descriptions indicate why these areas are included of the environmental and social issues here include the carrying and what types of effects might be realised in each case. The capacity of the land and whether or not use of land will eliminate total land area contained within the environmental study area is forests and wildlife from the area. A particularly interesting issue approximately 6,700 km2. The study areas include approximately 4,025 km of river, including the Mekong River. The study area also is the migration of wild elephants through the reselements area has a topographic relief between El 2,286 m and El 140 m. and the potential for increased human-elephant conflict. The host population in the reselement area will also be affected by some Zone 1: Inundation Zone construction activities, including portions of the headrace channel, Zone 1 consists of the area below El 538 m on the Nakai Plateau the intake structure, portions of Road 8B, some of the saddle dams that will be inundated by the reservoir. Since the tributary streams and some construction camp activities. 28 Location & Study Area EAMP Main Text Zone 4: Nam Theun Downstream to Theun-Hinboun Zone 9: Nam Kathang Headpond Zone 9 consists of the Nam Kathang and the riparian land from the Zone 4 encompasses the riparian land of the Nam Theun from regulating pond to its confluence with the Xe Bang Fai. This zone the Nakai Dam to the headwater of the Theun Hinboun reservoir, consists of approximately 1,632 households within 23 villages, and approximately 32 km downstream. Much of this Zone is included a population of approximately 12,722. This Zone will be not be in the NNT ­ Phu Hin Poun Corridor and is adjacent to much of affected by any increases in discharge. the corridor area. The Nam Phao discharges to the Nam Theun Zone 10: Upper Xe Bang Fai approximately 11.7 km below the Nakai Dam site. The riparian area along the Nam Theun ranges from approximately three to five The Upper Xe Bang Fai Zone extends from the confluence of the km wide. The area of Zone 4 is approximately 130 km2. There are NamKathangandtheXeBangFaitotheSayphouXoyRidgeabout noestablishedvillagesorpermanentselementsalongthisreachof 25 km downstream from Mahaxai. This gorge can cause backwa- Project the river. Environmental issues related to this area include riparian ter during flooding, aggravating flooding upstream of the gorge habitats, riparian releases from the Nakai Dam, and the plants and (SMEC 1996). Sixteen villages are located along the river reach. The animals that inhabit the area. The amount of riparian release from primary issues concerning the Xe Bang Fai in this area are related Description the dam will influence the fish populations in the Nam Theun. to increases in the quantity of discharge, changes in the discharge regime, erosion of river banks, changes in water quality, effect on Zone 5: Theun Hinboun Dam to Next Major Tributary land use along the river, effects on the fisheries and restrictions on Zone 5 includes the Theun Hinboun Reservoir and a riparian area crossing the river. along the Nam Kading that potentially stretches all the way to the Zone 11: Middle Xe Bang Fai Mekong River. Riparian releases to the Nam Kading beyond the Theun Hinboun Dam are considered to be within this Zone. Dis- The Middle Xe Bang Fai Zone extends from Sayphou Xoy Ridge to charge in the river will be limited to a minimum riparian release the Road 13 crossing and includes 12 villages. This reach will expe- from the Theun Hinboun Reservoir to the Nam Mouan at a dis- rience an increase in dry season discharge that may facilitate navi- tance of approximately 36 km below the Theun Hinboun Dam. gation and improve irrigation potential. Some of the villages have initiated dry season irrigation which may improve with additional Zone 6: Lak Sao Road & Quarry water in the Xe Bang Fai. Issues related to this zone will be similar to those highlighted for the Upper Xe Bang Fai, but the severity Zone 6 includes Road 8b south of Ban Lak Sao to approximately of the impact is expected to be less due to the distance from the the intersection of Road 8b and the border of Zone 2. A quarry downstream channel and the larger size of the channel. will be opened at Phou Phako to provide aggregate for construc- tion of the Nakai Dam and has been included in this study area. Zone 12: Lower Xe Bang Fai Issues related to the construction of the Nakai Dam include noise, The Lower Xe Bang Fai, or the Xe Bang Fai flood plain, covers air pollution, and water-related issues such as runoff and drainage. an area of about 50,000 ha, ranging from its confluence with the Additionally, the construction of a workforce camp in this area will Mekong River to where Road 13 crosses the Xe Bang Fai. This create issues related to waste disposal and cultural issues related includes approximately 70 km of river. The area is fairly densely to the quarry. populated, with some 52 villages, and with 40,000 ha of rice paddy Zone 7: Power Station to Regulating Dam fields it is a major area of rice production for Khammouane Prov- ince. The Lower Xe Bang Fai experiences natural flooding almost Zone 7 is a small area immediately surrounding the Power Station. every year and is hydraulically controlled by the Mekong. Environmental factors associated with the construction and opera- Zone 13: 500 kV Transmission Line tion of the Power Station are the primary issues to be considered. Other issues relate to water quality and quantity, diversion of flow Zone 13 extends from the bridge over the Xe Bang Fai on High- into the surrounding rivers and rerouting of the natural stream way 13 to Savannakhet along the route of the Transmission Line drainage around the regulating dam. There are no residents in the that will deliver power to EGAT. The effect of the 500 kV Trans- Zone, though there are a few gardens in the study area. mission Line upstream of bridge 13 will be discussed relative to other study areas. The primary issues relevant to this area are Zone 8: Downstream Channel from Regulating Dam to social. However, some forest may also be impacted by the Trans- Nam Phit/Xe Bang Fai Confluence mission Line. Another important issue relates to the crossing of the Mekong River. The proposed crossing is located immediately Zone 8 includes the downstream channel from the regulating upstream from Savannakhet. dam to the Xe Bang Fai confluence. Discharge of water from the Power Station will be diverted into the regulating pond and then Zone 14: Thakhek Road discharged through the downstream channel to the Xe Bang Fai. This Zone consists of the area along the road and the 115 kV The channel will impact rice paddies and will require modification Transmission Line delivering EDL power between Thakhek and of the Nam Phit channel. The Zone includes adjacent areas which Mahaxai. Social and environmental issues for the construction of will be modified as part of the construction of the channel. Primary the Transmission Line relate to habitat loss and human occupancy. issues are related to the selection of spoil disposal areas, placement This section of the 115 kV Transmission Line is not the responsibil- of embankments along the channel, placement of bridges along the ity of NTPC. Impacts resulting from upgrading the existing align- channel and the elimination of some wetland areas at the lower ment of the road are expected to be minimal. end of the channel. Environmental factors that will impact the area include the variable discharge to the channel and the quality of Zone 15: Mekong River water released from the Power Station, particularly in the early Zone 15 comprises the reach of the Mekong River between the con- years of operation. Approximately 60 households, who either use fluences with the Nam Kading and the Xe Bang Fai. Additional or occupy the land on the channel alignment, will be affected along consideration of potential impacts is related to the construction of the route. the 500 kV Transmission Line immediately north of Savannakhet. Location & Study Area 29 EAMP Main Text Table 2.6: Summary of economic analysis of the environmental and social impacts by the World Bank Project potential impacts Assessment Project activities AREA 1: Nam Theun Downstream Nakai Dam Positive impacts ·Suppression of flash floods. Negative impacts ·Fisheries (Diversity; Big-headed Turtle has thus far been observed only in the basin. Compensation package may amount to between 0.8 and Quantity) Present value of fisheries losses estimated at 1.2 million USD. 1.6 million USD depending on timing of implementation. ·Health Expected to be very limited given the absence of significant settlements along the banks of the Nam Theun. ·Domestic water use Idem. Description ·Agricultural water use Idem. ·Riparian wildlife and Impact mainly along first 12 km. However riparian wildlife and vegetation are vegetation observed throughout the water basin. rojectP Flood stage elevation is the primary concern along the Mekong scale of the Nam Theun Basin, (iv) the preferred habitat (fast flow- River but additional issues may involve migration of fish through ing water) of the Big-headed Turtle (Platysternon magacephalum, the area, navigation, and flooding. The Nam Theun 2 Project is one endangered on the IUCN's Red List, under Appendix II of the of many dams planned within the Mekong basin, and as a conse- CITES lists) will be impacted. The aggregate fisheries loss was esti- quence the impacts to this reach of the Mekong will be subject to mated at 1.2 million USD in present value terms. These losses are the cumulative impacts of all the proposed developments. expected to be fully compensated for by the project. The estimated cost of this compensation program is expected to range between Economic Analysis Environmental and 0.8 and 1.6 million USD, depending on the timing of programme Social Impacts implementation. Area 2. Nakai - Nam Theun NPA. An economic analysis of the environmental and social impacts was undertaken by the World Bank. It is presented briefly below by The NNT NPA is nationally and internationally recognized as one project area, and summarised in Table 2.6. of the most important biodiversity sites in South East Asia. It is generally recognized that the protected area is currently under Insofar as environmental and social impacts are concerned, the severe stress and that the current rate of harvesting of various most important feature of the Project is the trans-basin transfer of products is unsustainable, puing the wildlife and biodiversity approximately 220 m3/s of water (annual average) from the exist- under serious threat. Within the protected area currently lives ing Nam Theun into the Xe Bang Fai, and the inundation of part of approximately 1,100 households (5,500 people) with an average the Nakai Plateau. The diversion of water will alter the discharge level of total household income of approximately 400 USD in 1997. regime in both the Nam Theun (flow reduction) and the Xe Bang The primary and key positive impacts of the Project (and its con- Fai (flow increase). In addition, the inundation of part of the Nakai comitant watershed management plan ­ SEMFOP) appears clearly Plateau will necessitate the relocation of approximately 5,600 peo- to be: (i) improving natural resources management, (ii) protect- ple, and impact their existing livelihood systems. The Project aims ing and conserving the habitat and biodiversity, (iii) improving to improve the income and livelihood systems of these reseled the livelihood of its inhabitants, (iv) contributing to poverty alle- individuals. The Project, through the WMPA, will also imple- viation, and (v) preserving the ethnic diversity. It is estimated that ment a watershed management program which will contribute the project may reduce poverty by up to 35%. According to the significantly to the preservation of the NNT NPA. The extent of Economic Analysis (Laplante, 2005), the implementation of the the financial commitment (1 million USD per year), its duration SEMFOP cannot be justified solely on the basis that it is in the self- (over a period of 30 years), and its certainty represents a signifi- interest of the Project to invest in the improved management and cant contribution of the Project to the preservation of this unique conservation of the NNT NPAin order to prevent losses of energy biodiversity area. sale that could result for reservoir sedimentation. If the watershed Area 1. Nam Theun downstream. provides services to the Project such as the prevention of reser- voir sedimentation, the extent of these services would appear to be Total discharge in the Nam Theun immediately downstream of minimal (Laplante, 2005). the Nakai Dam to the confluence of the Nam Phao is expected to be reduced to 2 m3/s, from an average 734 m3/s in the wet season, Area 3. Nakai Reservoir. and 20 m3/s in the dry season. Total discharge in the Nam Theun The flooding of part of the Nakai Plateau entails both local and downstream from the Nam Phao is expected to be on average 51% global costs and benefits. The Project, through its livelihood pro- of existing conditions. The impacts expected are presented in the gramme will significantly contribute to poverty alleviation for the riparian release section of the EAMP: (i) fisheries will be impacted reselers by doubling the expected present value of aggregate in the Nam Theun and its tributaries, (ii) no adverse impacts are income (from 5 to 10 million USD), and by completely alleviating expectedonhuman-relateduseofthewateroftheNamTheun,(iii) poverty of these reselers (as measured against Lao poverty line). species recorded on the transects of the Nam Theun are common The project will further significantly increase access to improved in the surrounding forestenvironment,andtheriparianvegetation health care and education facilities, water supply, sanitation, and of the Nam Theun is commonly recorded over a wide geographic electricity. Thus, if the livelihood programmes effectively deliver 30 Economic Analysis Environmental and Social Impacts EAMP Main Text Table 2.6 (cont.) Project potential impacts Assessment Project activities AREA 2: Nakai Nam Theun National Protected Area Positive impacts ·Poverty alleviation ·Contribution to poverty alleviation ranging between 1.5 ­ 3.8 millions USD; The project will invest approximately 1 million USD per ·Health and education Reduction of poverty from 20 to 35%. year, pre and post COD. The present value of this package ·Cultural / ethnic diversity ·Qualitative assessment; Improved health facilities and better education amounts to approximately 10 millions USD. ·Habitat and biodiversity opportunities. ·Medicine and bio- ·Qualitative assessment; Improved opportunity to preserve cultural and ethnic prospection diversity. Project ·Carbon sequestration ·Qualitative assessment; Improved resource management aims to preserve habitat and biodiversity while simultaneously contribute to poverty alleviation. ·0.5 to 5 millions USD. In all likelihood, over-estimate to the extent that no such activities have thus far been observed. ·10 ­ 20 millions USD. In all likelihood, over-estimate. Description Negative impacts ·Increased population ·Qualitative assessment; The Project may increase pressure on the resources The SEMFOP aims to prevent this increased population pressure on the resources of the NPA. pressure from exercising an adverse impact on the NNT NPA. of the NNT NPA. AREA 3: Nakai Plateau / Reservoir Positive impacts ·Poverty alleviation; ·Double the present value of income (from 5 to 10 millions USD) of resettlers; ·Health and education; completely eliminate poverty (measured against Lao poverty line) of resettlers; ·Domestic water, ·Qualitative assessment; Improved health facilities and better education sanitation, electricity; opportunities; ·Reduction in GHG emis- ·Qualitative assessment: Improved access to domestic water supply, sanita- sions: Hydro vs. CCGT; tion, and electricity; ·Potential habitat ·Estimated present value of global economic benefits: 34 millions USD; improvement for White- ·Qualitative assessment: Habitat for White Winged Ducks may improve as a Winged Ducks; result of expansion of forested wetlands Negative impacts ·Increased emissions of ·Estimated present value of costs: 26 to 44 million USD; ·Conservation programme will be initiated. GHG from reservoir. ·Qualitative assessment; Loss of area generally not believed to be critical to ·Loss of habitat for Asian the survival of the local population of Asian elephants; elephants; ·Qualitative assessment; Area of the Plateau to be impacted by both im- ·Loss of other habitat and poundment and by resettlement is not considered of high biodiversity value biodiversity. (considering species richness, degree of endemism, rarity, vulnerability, and representativeness of component species.) Project induced impact ·Recreation and com- ·Estimated present value may range in the order of 0.5 million USD. This ·Necessary investment not in Project budget costs. munity-based tourism. would appear to be a conservative estimate. AREA 4: Xe Bang Fai Negative impacts ·Loss of fisheries; ·Estimated present value of losses: 4 million USD; ·All fisheries losses recovered with mitigation plan budgeted ·Loss of riverbank ·Estimated present value of income losses: 0.25 to 0.6 million USD; at 8.5 million USD ­ or 5 million USD (in PV terms);. gardens; ·Estimated present value of losses reach 2 million USD; ·All riverbank garden losses recovered with mitigation plan ·Loss of crop yields ·Qualitative assessment; The number and nature of assets needing riverbank budgeted at 0.35 million USD ­ or 0.3 million USD (in PV ·Fixed infrastructure as- protection or relocation remains to be precisely determined; terms); Budget allocated by NTPC may not be sufficient; sets (shops, houses, barns, ·Qualitative assessment; 19 pump irrigation systems may be affected as a ·Losses of crop yield are expected to be completely mitigat- temples, pavilions, etc.) result of river bank erosion; ed by the Project through the raising of river embankments. ·Irrigation infrastructure; ·Qualitative assessment; A number of existing crossing facilities will not be ·All identified assets will be either protected or relocated; ·River crossing and possible as a result of the higher water flow and water level; mitigation plan budgeted at 0.65 million USD ­ or 0.42 transport; million USD (in PV terms); ·All affected irrigation infrastructure will be revised as ap- propriate; mitigation plan budgeted at 0.05 million USD ­ or 0.03 USD (in PV terms); ·Alternative crossing facilities will be provided and con- structed by the project; mitigation plan budgeted at 0.2 million USD ­ or 0.13 million USD (in PV terms); ·Alternative sources of domestic water supply will be pro- vided; mitigation plan budgeted at 0.12 million USD ­ or 0.08 million USD in PV terms. Project induced positive impacts ·Reduced pumping costs; ·Estimated present value of savings may reach 0.3 million USD; ·Increased irrigated ·Estimated present value of net revenues (not inclusive of investment costs) agriculture; range between 5.2 and 7.5 million USD; ·Electricity. ·Increased availability (20 MW) and reliability of electricity supply in the XBF region. Economic Analysis Environmental and Social Impacts 31 EAMP Main Text intended income targets and service delivery objectives, the live- It has also been shown that the Project offers the potential for large lihood of the reselers is expected to improve very significantly positive induced impacts especially the increased potential for irri- over conditions that would assume to exist in the absence of the gated agriculture. Early estimates show potential revenues in the Project. The Project is expected to reduce emissions of GHG by order of 4 to 6 million USD (present value) over the lifetime of the approximately 20 million tons over the horizon of the analysis Project. A rural development project will provide a beer assess- (avoidedemissionsof 50milliontonscomparedtoCCGTminusan ment of this potential. However, such positive induced impacts estimated 30 millions tons of emissions from the reservoir itself). However, given the significantly different timing of these events (a must account for the fact that if additional quantities of water may bulk of the emissions from the reservoir is expected to take place be source of economic benefits on the XBF, then reduced quantities early on following impoundment), the present value of these bene- of water available along the Nam Theun basin may be source of fits may or may not be positive. Finally, insofar as wildlife and bio- economic costs. diversity are concerned, existing information does not support the The lower XBF is also subjected to periodic and large flooding. The notion that the impacted area (Plateau and reselement area) is of Lower XBF Hydrology Study (SMEC, 2004) reveals that existing high biodiversity value. The White Winged Ducks, if its presence flooded area may experience an additional 3.6 days of flooding. is confirmed, may benefit from the project as the impoundment If this were to be the case, productive rice yields could be signifi- Description of the Plateau will lead to an expansion of forested wetlands. The cantly impacted, with an estimated expected loss ranging between habitatoftheAsianElephantsisexpectedtobeadverselyimpacted 0.4 and 0.55 million USD per year, or approximately 3 million USD by the Project, though not to the point of threatening the viability in present value terms. However the release of water from the of the elephants in the area. For both of these species, conservation Project will also give the potential to develop in this same area two rojectP programmes will be put in place by the Project to facilitate their dry season crops not vulnerable to flooding. adaptation to the new environment. Area 4. Xe Bang Fai. Area 5: Mekong River. Numerous impacts (both negative and positive) are expected The Cumulated Impact Analysis study (Norplan, 2004) indicates along the Xe Bang Fai. Adverse impacts include mainly: (i) loss no or very minimal impact ­ both negative and positive ­ along the of fisheries, (ii) the loss of river bank gardens, and (iii) the loss of Mekong River, including Cambodia's Great Lake and floodplains. assets including potentially cultural sites. If the activities described Area 6: Project lands. in the SDP are delivered and are effective as currently expected, the analysis shows that all known potential adverse impacts of Estimates indicate an opportunity cost of land ranging from 1,000 the Project will for the most part if not completely be mitigated or to 4,000 USD per ha. The ConcessionAgreement allows the Project compensated for. The largest of these adverse impacts pertain to an area of approximately 11,500 ha. However, the Project does the loss of fisheries income with losses estimated at approximately not anticipate all of this area to be effectively used by the Project. 0.7 million USD per year. The mitigation plan is expected to com- Given that infrastructure design has not been completed, it is not pletely mitigate these losses, leaving households of the XBF at least currently possible to assess the aggregate opportunity cost of land as well off as without the Project. to acquired or effectively used by the Project. 32 Economic Analysis Environmental and Social Impacts EAMP Main Text 3. Assessment of Environmental Impacts Global & Regional Issues 34 Greenhouse Gases 34 Global Biodiversity 35 Trans-basin Diversion of Water 35 Cumulative Impact Assessment 36 Introduction and Scope 38 Intact River Assessment 38 Regional Biodiversity 38 Topography, Geology & Soils 39 Baseline 39 Potential Impacts 41 Erosion & Sedimentation 42 Reservoir Area 42 In-Stream Degradation 43 Climate 45 Baseline 45 Potential Impacts 48 Hydrology & Water Resources 50 Baseline Hydrology 50 Baseline Groundwater Hydrology 54 Potential Impacts 54 Proposed Mitigation Measures, Enhancements & Compensation 61 Riparian Release 65 Impacts The Riparian Release 66 Geographical Description 66 Sources of Baseline Data 66 Baseline 66 Impacts 75 Mitigation 83 Compensation 84 Community Consultation 84 Monitoring 84 Water Quality 85 Baseline Groundwater Quality 87 Predicted Water Quality in the Nakai Reservoir & Impacts 87 Predicted Water Quality Downstream from the Power Station & Impacts 90 Social Impacts of Water Quality Changes 92 Mitigation of Potential Water Quality Impacts 92 Monitoring 94 Aquatic Habitats & Fish Diversity 96 Fish Habitats 97 Fish Diversity & Endemicity 99 Faunistic Affinities 100 Fish Populations 101 Migrations 102 Fisheries 103 Potential Impacts on Aquatic Habitats 103 Terrestrial Biodiversity 110 Baseline 110 Threatened Species 120 Natural Habitats Accounting and Adequacy of Offsets 121 Impacts Associated with Construction 132 General Impacts Generated by all Construction Activities 133 Impacts Associated with Specific Construction Activities 134 Other Impacts Associated with Construction Activities & Project Developments 137 Physical Cultural Resources 150 Pest Management Plan 155 T his chapter starts with a description of global issues such as the production of greenhouse gases and global biodiversity. This is followed by a presentation of regional issues, trans- basin diversion of water, intact river assessment, and regional bio- diversity. The second section focuses on Project-specific issues. Global & Regional Issues 33 EAMP Main Text Table 3.1: Comparison of generation per area flooded of several hydropower projects Reservoir Area Generation Generation per area Flooded Project (km2) (GWh/year) (GWh/year/km2) Balbina, Brazil 3,147 970 0.3 Tucurui, Brazil 2,247 18,030 8.0 Churchill/Nelson Canada 1,400 16,000 11.4 Grand Rapids Canada 1,200 1,700 1.4 Nam Theun 2 450 5,636 12.5 The approach taken in this section is to first describe the baseline global GHG. Greenhouse gases will be produced throughout the conditions and significant environmental issues, then to evaluate life of the reservoir, with higher GHG emissions in the first few the potential environmental impacts, and finally to identify ways years aer inundation. Ultimately, the original carbon stock will be of avoiding these impacts. Mitigation measures, compensation dissipated as it: i) is diffused as gases to the atmosphere through measures and opportunities for environmental enhancement are the reservoir surface; ii) is transferred as gases to the atmosphere discussed. The third section of the chapter focuses on the general fromreservoirwatersinthedownstreamchannelandriversdown- and specific impacts associated with construction. stream from the PowerStation and spillway; iii) is converted into new life in the reservoir water or released water; and iv) remains Global & Regional Issues stored in submerged and fallen trees. ThepotentialforGHGproductioncanbegaugedontheratioofthe Two globally significant issues related to the Project are the poten- annual GWh generated to the area flooded (McCully 1996). Table tial for climate change due to production of greenhouse gases, 3.1 illustrates that the NT2 Project is favourably placed in terms of and potential impacts to biological diversity.Anumber of regional generation per area flooded when compared to other hydropower issues have been identified as potentially influenced by the Project. projects. It is improved further by the fact that forests cover less These include: i) the trans-basin diversion of water; ii) CIA; iii) than 50% of the inundation area. intact river assessment; and iv) regional biodiversity. It has been calculated that when power generation is less than 0.1 Impacts Greenhouse Gases W/m2 of reservoir area, thee risk that GHG emissions exceed that of thermal generation for the equivalent capacity is high. Where The Project could have some implications relative to contributing values exceed 0.5 W/m2 of reservoir, scenarios have shown that this to global climate change through the production of greenhouse risk is reduced (WCD, 2000). gases. There are two important factors relating to the contribution of GHG i) the amount of GHG generate by the Nakai Reservoir; Several factors are considered when calculating the GHG emis- and ii) comparison of the amount of GHG generated with produc- sions of the Project; including i) the amount of organic maer to tion of GHG by fossil-fuelled power stations. be inundated; ii) methane emission from the reservoir; and (iii) seasonal drawdown. Based on calculations made for the Petit Following inundation of part of the Nakai Plateau, the store of Saut Hydropower Project in French Guyana (Delmas, 2000), it is organic carbon from the above ground vegetation (40 t (C) / ha) estimated the Project reservoir will produce only 50 to 80% of the and from the soil (70 t (C) / ha) will decompose. Nutrients will be estimated GHG emission of the Petit Saut reservoir. This is firstly released to the water and additional organic production will take because of a lower estimated amount of organic maer that will be place. The decomposition of carbon will result in the production subject to decomposition (5 million tonnes vs. 8.5 millions tonnes) of carbon dioxide (CO2) and methane (CH4), the two greenhouse and secondly due to a significantly larger drawdown area. This gases (GHG) most responsible for the anthropogenic increase in greater area means that a larger proportion of the organic maer will be oxidised to CO2 rather than to CH4, a gas more effective at inducing warming than CO2. Delmas and Garly-Lacaux (2000) compared the emission of GHG from the Project and a thermal power plant of similar generating capacity over a 100 year time-scale. As shown in Figure 3.1, emis- sion of greenhouse gases from the reservoir represents less than ten percent of the emissions of a thermal power plant of compa- rable capacity. Furthermore the information presented in Figure 3.1 is based on a constant production of greenhouse gases over a 100-year period, when in fact methane emission is most significant during the first five years aer impoundment, due to fast decom- position of the easily biodegradable fraction of the biomass in the form of leaves and grass. Establishing that a reservoir emits GHG is not enough to assess the overall net impact. Natural habitats may also emit GHG, especially the areas of seasonal wetlands and wetland rice currently within theinundationarea.However,duetothelimiteddataavailable,the overall net fluxes from the reservoir were not taken into account in Figure 3.1: Comparison of cumulated greenhouse gas emissions the calculations above. This certainly leads to an overestimation (Res. Low = 50% of Petit Saut Reservoir Emission; Res. High = 80% of Petit Saut of emissions from the reservoir which would be considerably less Reservoir Emission) than that of any thermal alternatives. 34 Global & Regional Issues EAMP Main Text Mitigation To date, no experience exists with minimizing, mitigating, or com- pensating the impact of GHG production. Pre-inundation removal of vegetation is one alternative that will be implemented by the Project, but the net effects of such an activity are not well under- stood (WCD, 2000). In addition, dissolved and particulate organic carbon fluxes from watersheds make a contribution to the produc- tion of GHG (Delmas 2000). Under the SEMFOP, the management of the NNT NBCA should help prevent any significant contribu- tions to GHG being made by reservoir inflows. Global Biodiversity Lao PDR is one of the most biologically diverse areas in the world, with its central region recognised internationally as an area of out- standing biological diversity. Three NBCAs surround the immedi- ate Project area. The most important of these is the NNT NBCA, which constitutes about 88% of the drainage for the reservoir. The other two NBCAs are the Phou Hin Poun NBCA, a region of karst limestone, and the Hin Nam Nor NBCA, located to the south of the NNT NBCA. Management of the NNT NBCA forms an important component of the Project's compensation and mitigation meas- ures. Project commitments to the protection of the NNT NBCAare discussed below. AsaconsequenceofstudiesconductedbytheIUCNandWCS,and with recommendations from the World Bank, a series of corridors Impacts between the NBCAs was established in 1993 by PM Decree 193. These corridors, shown in Figure 3.2, have effectively connected the three NBCAs to enable migration of wildlife between them. Figure 3.2: NBCAs and corridor areas Each of the areas is noted for the presence of several threatened and endangered species including the Asian elephant, the tiger, the Project is not operating for more than 16 hours in a given day, and the white-winged duck, as well as a number of other species the diversion may drop below 30 m3/s. identified by IUCN as globally endangered or threatened. During the IUCN/WCS studies, three new mammal species were identi- A consequence of the diversion of water from the Nam Theun to fied as inhabiting the NBCAs. These included the saola, a new spe- the Xe Bang Fai is that the discharge in the Nam Theun down- cies of muntjac, and a new rabbit or hare species. The Heude's pig, stream of the Nakai Dam will be reduced to a minimum weekly long thought to be extinct, has recently been rediscovered in the average of approximately 2 m3/s during the dry season. An anal- area. Fish studies have also identified numerous new species. ysis of the riparian release, and the implications of the reduced discharge on fish populations downstream of the Nakai Dam, is A number of activities currently threaten the NNT NBCA and to be conducted during the dry season of 2004. This change in dis- therefore threaten the survival of its globally important biodiver- charge will primarily affect approximately the first 12 km of the sity. These activities include (i) logging; (ii) commercial extraction Nam Theun downstream of the Nakai Dam, aer which a major of wildlife and non-timber forest products; and (iii) unsustainable tributary, the Nam Phao, joins the river. In addition to affecting agricultural systems that utilise short-cycle swidden practices. It is the fish populations in the Nam Theun, the diversion of water will therefore essential to allocate sufficient resources for the manage- also influence the operation of the Theun Hinboun Hydroelectric ment of the NNT NBCA to prevent any further degradation of its Project, located downstream from the Nakai Dam. regionally and globally recognized biodiversity. Hydrologic Changes in the Mekong River Trans-Basin Diversion of Water The annual flow in the Mekong River, over a distance of 189 river A major regional issue relative to the operation of the Project is kilometres from the Nam Kading to the Xe Bang Fai, will be some- the trans-basin transfer of water from the Nam Theun to the Xe what reduced due to diversion of water from the Nam Theun to Bang Fai. the Xe Bang Fai. The activities of both the Project and the Theun Hydrologic Changes in the Nam Theun & Xe Bang Fai HinbounHydroelectricProjectwilldecreasethedischargeofwater to the Mekong from the Nam Kading. Over the year, the average The diversion of water from the Nam Theun to the Xe Bang Fai will reduction in discharge in the Mekong between the Nam Kading dramatically alter the discharge regime in the Nam Theun down- and the Nam Hinboun is estimated to be 302 m3/s. Between the stream of the Nakai Dam and in the Xe Bang Fai downstream of Nam Hinboun and the Xe Bang Fai, the Project will decrease the the Nam Phit. When the Project is operating to meet peak power discharge of the Mekong River by an average of approximately demands in Thailand and Lao PDR, the power station will divert 220 m3/s. However, the reduction in discharge to the Mekong is up to a maximum of 330 m3/s of water from the Nakai Reservoir relatively small in comparison with the total discharge in the river. filled by the Nam Theun to the Xe Bang Fai. On average, the diver- Average discharge for the Mekong at Nakon Phanom is approxi- sion of water from the Nam Theun to the Xe Bang Fai will be mately 7384 m3/s. Consequently, the diversion of water caused by approximately 220 m3/s. Occasionally, the inter-basin transfer may the Project is only about three percent of the total discharge in the drop as low as 30 m3/s when the Project is not operating to meet Mekong River, and therefore it is expected that the diversion will baseload or intermediate peaking requirements. Additionally, if not impact navigation or fish populations significantly. Global & Regional Issues 35 EAMP Main Text The Theun Hinboun Hydroelectric Project diverts approximately Effects of Diversion on the Xe Bang Fai 82 m3/s of water from the Nam Theun to the Nam Hinboun (RMR, 2000). Even when the Project is combined with this diversion, the Diversion of water from the Nam Theun to the Xe Bang Fai will variations in flow produced fall well within the natural range of have a number of impacts on hydrology, river morphology, water annual variation in the Mekong. Unregulated, the Nam Kading quality, fisheries and the livelihoods of people living along the Xe contributed a mean annual volume of over 697 m3/s to the Mekong Bang Fai. To ameliorate the increased flow, a regulating dam and River. The trans-basin diversion from both Projects is approxi- pond will be constructed immediately downstream of the Power mately 302 m3/s, or 43% of the unregulated flow of the Nam Kad- Station to regulate releases from the Power Station and ensure a ing. relatively constant flow into a downstream channel during the period from Monday to Saturday. Part of the regional implications of diverting water from the Nam Theun to the Xe Bang Fai is the potential impact on the Mekong When the Power Station is generating electricity, much of the water estuary. During the rainy season, the reservoir will store water in will be stored in the regulating pond. Controlled release from the the reservoir and consequently reduce discharge to the Mekong regulating pond will enable a more constant flow to the Xe Bang downstream from the mouth of the Xe Bang Fai. This could result Fai, thereby reducing discharge fluctuations in the river channel. in some degree of salt water intrusion into the estuary. However, Experienceelsewhereindicatesthatfluctuatingdischargesincrease the average flow at Phnom Penh between June and September is the potential for erosion of riverbanks. Consequently, maintenance 26,200 m3/s. Therefore an average discharge reduction of approxi- of a relatively constant flow in the Xe Bang Fai will reduce the mately 500 m3/s in August represents a reduction of less than two potential for erosion. However, to reflect power demand on Sun- percent of the flow at Phnom Penh: the reduction in discharge of days, the amount of water discharged from the regulating pond the Mekong during flood season will not be significant. During to the downstream channel may be reduced to a minimum of 30 the dry season, the Project will supplement the discharge to the m3/s. Mekong River and saltwater intrusion into the estuary may be less- The normal dry season discharge in the Xe Bang Fai is approxi- ened. On average, discharge to the Mekong during the dry season mately 20 to 30 m3/s. Therefore the Power Station will increase the will increase by approximately 220 m3/s, with periodical increases discharge in the river by about tenfold during the dry season and it of 330 m3/s. During periods of low discharge in the Mekong, the isexpectedthattheriverchannelwillbeeroded.Erosionwill occur Project's supplement to the discharge will actually reduce saltwa- through a combination of weekly fluctuations in water level and ter intrusion into the estuary compared to current levels. When because water diverted from the reservoir will have a small sedi- discharge is reduced to 30 m3/s, saltwater intrusion will be approx- ment load. As a consequence, the increased discharge will have a Impacts imately the same as it is under current conditions. The Cumulative considerable capacity to carry sediment and erode the banks. The Impact Assessment study currently being carried out will provide Xe Bang Fai's morphology will continue to enlarge until the river further information about Project impacts on the Mekong River. stabilises at a new cross section that can accommodate the low sediment-loaded Project discharge and water level fluctuations. Effects to Operation of the Theun Hinboun Project The adjustment of the Xe Bang Fai channel will likely occur over a The third major issue is how diverting water from the Nam Theun period of a number of years. willaffecttheoperationoftheTheunHinbounProject.Priortocon- Within the downstream channel, an aeration weir will be con- struction of the Theun Hinboun Project,the Theun Hinboun Power structed to aerate water discharged from the power station, with Company (THPC) simulated operations both with and without the the objective of increasing dissolved oxygen and decreasing the Nam Theun 2 Project. EGAT's request to operate the Nam Theun 2 amount of methane in the water. Project on an intermediate peaking basis has introduced a change During the rainy season, discharge from the Power Station will be in the design of the power station since the evaluation of impacts restricted so that the Project does not contribute to natural flood- to the Theun Hinboun operation was conducted. However, the ing in the Xe Bang Fai region. When discharge in the Xe Bang Fai design changes did not alter the anticipated operational impact on at Mahaxai approaches 1,970 m3/s, discharge from the power sta- Theun Hinboun power generation capacity and downstream dis- tion will be reduced and will have ceased before the flow in the charges. Analysis of Project impact on the Theun Hinboun project Xe Bang Fai at Mahaxai reaches 2,270 m3/s, in order to prevent the indicates that generation of energy by the Theun Hinboun power Project from causing any additional overbank flooding in the Xe station will be reduced by just over 15% compared with pre-Nam Bang Fai. Theun 2 Project generation. The spills from the Theun Hinboun diversion reservoir will decrease from an average 245 days to an Cumulative Impact Assessment average 190 days per year when the Project becomes operational (i.e. from 67% to 52% of the time).As a corollary, the periods when Introduction and Scope riparian discharge immediately downstream of the Theun Hin- Given the potential for Project impacts to have wider implications boun dam are limited to the minimum riparian release of 5 m3/s when considered in the context of other development trends, a will increase from an average of 120 days to an average of 175 days Cumulative Impact Analysis (Norplan, 2004), was undertaken per year. Combined energy yield from the two hydropower sta- to analyse the combined impacts of a number of projects, either tions will increase by approximately 350 percent to an estimated implemented together or in a sequence and of future develop- 7,100 GWh per annum (Lahmeyer Meritec, 2000), based on the ments and plans, in relation to the Project. The scope of the CIA assumption that the installed capacity at the Nam Theun 2 Project includes effects other (future) developments have on the type and will be 1,070 MW. The Theun Hinboun power station will continue magnitude of Nam Theun 2 impacts (added impacts); and impacts to receive benefits from operation through the Project construc- of development in other sectors that are induced by the Nam tion period and during the period when the reservoir is filling. Theun 2 Project (induced impacts).The geographical coverage of Analyses have shown that additional flow could be released from the CIA includes the Mekong Basin, Nam Theun/Nam Kading, Xe Project during the filling period and that partial regulation could Bang Fai and Hinboun basins and the linear development zone of be afforded by the cofferdam during construction (Lahmeyer-Mer- transmission lines and roads. In addition, border areas are covered itec, 2000). in relation to social development, transport and biodiversity. 36 Global & Regional Issues EAMP Main Text Table 3.2: Cumulative Impacts of Anticipated Regional Developments Including Nam Theun 2 Project Impact Zone 5-year scenario 20-year scenario Nakai Plateau Impacts dominated by Project activities. Some additional im- Situation stabilized but significantly changed compared to current baseline. Trans- pacts envisaged due to improved access following the construc- port communications will be significantly improved and new activities will have tion phase and temporary population increase. been attracted to the reservoir (e.g. commercial fisheries and tourism). Anticipated Key impacts will be increased pressure on wildlife (e.g. from situation is: hunting and logging due to an influx of people and better (i) Sanitation and water supply improved access to the area), increased health risks (STDs including (ii) Oudomsouk population higher than during the Project construction period by HIV/AIDS) and increasing frequency and severity of vehicular some 140-150% accidents. (iii) Commercial fisheries will be established (iv) Health conditions improved with reduced incidence of malaria and food and water borne diseases, and shift from communicable towards non-communica- ble diseases (v) Health and education services improved (vi) Increased employment in service sector including tourism (vii) Increased cultural integration on the Plateau with blurring of ethnic identities NNT NPA (i) Reservoir will affect fish migration in the Nam Theun (i) Change in fish biodiversity and production dependent on type of fish population (ii) Better protection of biodiversity and forest resources through that establishes in the reservoir SEMFOP but also increased threats linked to road construc- (ii) Increased threat to biodiversity due to population increase on the Vietnamese tion and population increase on the Vietnamese side of the side of the border and increased exploitation of the NPA border (iii) Further improvements in social services including immunisation coverage, (iii) Improved delivery of social services including access to hygiene and nutrition, health centres and functioning village schools education, availability of medicines, possible reductions of (iv) Considerable out-migration and labour migration to urban areas due to malaria and nutritional problems natural population increase (iv) Some integration of ethnic minorities but not to the same (v) Process of integration with lowland Lao culture will have proceeded further and extent as on the Plateau led to assimilation of small Vietic groups (v) Some improvement in poverty alleviation (vi) Significant reduction of poverty in terms of food security, better market access (vi) Improved management and enforcement efforts in the NNT and employment NPA may increase pressure on other NPAs Impacts Xe Bang Fai Basin Impacts of Project operation have started to be felt. New Road No new large-scale hydrological changes are foreseen, but the transport corridors and Surrounding 12 will also have significant impacts. Cumulative impacts are and accompanying urbanization will be a significant development in relation to Districts likely to be: cumulative impacts. Situation likely to be: (i) Increased untreated wastewater due to higher population (i) Reduced problem of oxygen depletion due to less organic matter in the reservoir around Gnommalat and Mahaxai and improved wastewater treatment (ii) Commercialisation and intensification of agriculture in (ii) Localised eutrophication and increased levels of pesticides in rivers and fish due Mahaxai and Gnommalat, but only moderate expansion in to intensified agriculture irrigated rice area (iii) Reduced biodiversity and fish production due to disturbed spawning cycles (iii) Increased logging in undisturbed forest and other areas caused by changed hydrological regime. However increased flooding may (iv) Considerable expansion of Gnommalat and Mahaxai set- increase flood plain and swamp production of fish tlements (iv) Improved sanitation, health services and awareness on health issues. Water- (v) Increased prevalence of STDs (e.g. HIV/AIDS) and vehicular borne illnesses and intestinal parasitic infestations substantially reduced and accidents more common mortality from malaria and dengue fever strongly reduced (vi) Capacity of the various district services considerably (v) Substantial growth of Mahaxai and Gnommalat (perhaps by 200%) and of Tha- strengthened due to Project support khek (by 140-150%). Growth in service sector including tourism and expansion of cement industry in Mahaxai creating employment (vi) Some assimilation of ethnic minority groups in urban areas will have occurred, but cultural identity will be retained in rural areas Nam Theun, Nam Nam Kading and Nam Hinboun will experience the combined No further hydropower expansion planned in the basin. Development will be domi- Kading and Nam impacts of Nam Theun 2 and Theun-Hinboun Extension nated by increase in transport related activities and impacts and developments on Hinboun basins and Projects, in addition to the developments caused by improve- the Plateau. Situation likely to be: surrounding districts ment of Road 8 corridor, and increased cross-border trade and (i) Increased pressure experienced in Nam Kading NPA, Phou Hin Poun NPA and population movement. Predicted impacts are: Nam Chat/Nam Pan Provincial Conservation Forest due to increased pressure (i) Reduced discharge in Nam Kading (below Theun Hinboun of cultivation, logging and hunting and as a result of improved protection of dam) in the flood season. With the Theun-Hinboun Exten- NNT NPA sion, cumulative impact will be diversion of a larger part of (ii) Rural-urban migration trend reinforced and size of Lak Xao increased to the flood into the Nam Hinboun further reducing flows in the 27,000 ­ 28,000 Nam Kading (iii) Full assimilation of smaller ethnic groups, in or near Lak Xao (including some (ii) Reduced flood periods affecting fish migratory behaviour Vietic groups), loosing their ethnic identity (iii) Increased threats to biodiversity due to population increase (iv) Hmong cultural traditions and language are likely to continue despite changes and increased trans-border traffic. in the socio-economic conditions (iv) Remaining and limited forested areas increasingly en- croached upon but participatory village forestry will have been introduced (v) Increase in irrigated areas and irrigation schemes along Nam Hinboun (vi) Population of Lak Xao increased to 17,000 - 18,000, partially due to in-migration (vii) Gradual integration of ethnic groups into mainstream economy will be accelerated slightly due to Nam Theun 2 related activities, population influx, increased urbanisa- tion, improved infrastructure and growth in service sector. Vulnerable Vietic groups will be under particular pressure of integration. Global & Regional Issues 37 EAMP Main Text Table 3.2 (cont.): Cumulative Impacts of Anticipated Regional Developments Including Nam Theun 2 Project Impact Zone 5-year scenario 20-year scenario Mekong River Basin Dominant factor will be some additional development of Dominant impact will be further development of hydropower in Yunnan (China) (Scenarios include hydropower in Yunnan (China) and Lao PDR. The impacts are and Lao PDR. Impacts are calculated to be: all hydropower calculated to be: (i) Dry season discharge at Savannakhet may increase by 135%. During floods, developments in (i) Dry season discharge at Savannakhet may increase by 45%. discharges may reduce by 22% the basin including During floods, discharge reduced by 7% (ii) Water levels at Phnom Penh will be lowered further during floods and increased Yunnan) (ii) Water levels at Phnom Penh will be lower during floods and further during the dry season. Average annual maximum level of Tonle Sap lake increased during the dry season. Average annual maximum will be further reduced. level of Tonle Sap lake will also be reduced (iii) Changes in flow pattern will have a significant negative impact on floodplain (iii) Changes in flow pattern will have a small negative impact and Tonle Sap lake fisheries on floodplain and Tonle Sap lake fisheries as these are (iv) Changes in flow patterns will however have a significant positive impact by favoured by high wet season water levels damping damaging flood incidents and by increasing dry season water levels (iv) Changes in flow pattern will however have a small posi- that will support irrigation and reduce salt intrusion in the Mekong Delta tive impact by damping damaging flood incidents and by increased dry season water level that will support irrigation and reduce salt intrusion in the Mekong Delta Two development scenarios have been assessed based on a 5-year for improving the management of environmental and social issues and 20-year planning horizon. These scenarios cover a number within the sector. Broad recommendations relevant to all potential of sectors by examining the present situation, existing plans and developments in the sector include water and land related mitiga- development trends. Sectors covered are: hydropower, transport, tion measures, compensatory programmes including catchment irrigation, water supply and sanitation, urban development, fish- protection, forestation plans, fisheries development plans, social eries, forestry, industry, social development (including ethnic and ethnic minority development plans and nature protection minorities, health, education and social disparity), and conserva- measures. Strengthening the capacity of GOL and its agencies to tion (biodiversity issues). Of all these sectors, hydropower is the understand and take account of environmental and social issues is most planned and has the greatest potential to affect the whole also recommended. Mekong Basin in terms of active (seasonal) storage of water. This results in increased dry season and decreased wet season flows. Intact River Assessment Impacts Cumulative Impacts of Anticipated Regional Development The conservation of fresh water ecosystems throughout the world has become a significant issue, relative to the development of A summary of anticipated cumulative impacts of Nam Theun 2 hydropower projects as well as water supply systems and irriga- when combined with the anticipated developments in other sec- tion systems. In many countries, policies for establishing intact tors described above over a 5 and 20 year planning horizon are river systems have become a national priority. Means for retaining presented in Table G.1. river systems as intact rivers are developing in the United States, The CIA also examined the specific contribution of the Project Switzerland, Norway, Sweden, and other countries around the to the downstream changes in the Mekong described above. The world. Project alone is predicted to result in an increase (of c. 8%) in dry The Hydropower Development Strategy Study (Worley Interna- season discharge at Savannakhet while reducing flood discharges tional, 2000) suggested that GOL establish a policy for retaining by 2%. The Nam Theun 2 reservoir is also expected to cause only some of the rivers within Lao PDRas "intact rivers", thereby main- minimum retention of sediments. taining the diversity of habitats and species within those basins. TheCIAconcludedthattheNamTheun2Projectalonewillhavean This is being considered by GOL. insignificant (significance is based on whether or not the induced impacts of the Project are within the range of normal fluctuations) Regional Biodiversity negative impact on the Mekong floodplain and on all aspects of the The designation of the NBCAs forms an integral part of maintain- Tonle Sap lake including fish production. It recommends a number ing biological diversity in the region. Significant areas of forest of best practice actions to mitigate and compensate impacts of exist on the eastern side of the Mekong River basin. However, on developments and predicts the results of these actions on the 5- the western side, much of the forests has been converted to agricul- year and 20-year scenarios. These recommendations will be con- tural production. The designation of more than 20% of Lao PDR's sidered by GOL and jointly discussed and implemented with the area as NBCAs is a prime regional and global issue. donor community and international agencies such as the Mekong River Commission. Impacts of the Project on terrestrial and aquatic biodiversity are discussed later in this chapter. An initial contribution of US$ 6.6 Sectoral Environmental Assessment of the Hydropower million, together with an annual contribution, during operation, of Sector US$ 1 million from NTPC to the management of the NNT NBCA, will assist maintenance of biological diversity of the area and will The Lao Hydropower Development Strategy was developed based enable maintenance of a managed watershed for delivery of water on a series of studies on the power sector undertaken over the last to the reservoir. The provision of financial assistance to manage 10 years. Many of these studies, have incorporated environmen- this protected area is important on both a global and regional level. tal and social criteria in choosing alternative hydropower devel- The NNT NBCA is the largest protected area within Lao PDR and opment plans and discussed the environmental and social issues is considered to be one of Asia's most important protected areas related to development in the sector. A Sectoral Environmental (Robichaud2002)andofoutstandingimportanceintermsofglobal Assessment for the Lao Hydropower Sector (Norplan, 2004) has biodiversity(MacKinnon1997).TheNNTNBCAisalsorecognized been undertaken to consolidate, update and expand this previ- as having the greatest extent and quality of forest cover (Berk- ous work in order to clarify the broader issues faced by hydro- muller et al 1995), and is ranked highest in terms of threatened power development in Lao PDR and develop strategic priorities bird and mammal species (Ling 1999). Regionally, the NNT NBCA 38 Global & Regional Issues EAMP Main Text borders the Vu Quang Nature Reserve in Vietnam and is directly where the saddle dams will be constructed to prevent loss of water linked to the PHP NBCAand HNN NBCAin Lao PDR by corridor over the escarpment. This lip marks the top of a prominent escarp- areas. Given its central location, the NNT NBCA is considered the ment, which drops down to the Nam Kathang and Nam Hinboun cornerstone for the system of protected areas in the region. Mainte- basins. Downstream, these two valleys and the main streams they nance of the watershed, particularly as an intact forest, will reduce join cross a highly karstic limestone formation marked by rugged the potential for sediments to flow into the reservoir and thereby topography, with pinnacles rising 400 m. This area has been des- reduce the storage capacity of the reservoir. This financial contri- ignated the Phou Hin Poun NBCAand is not directly impacted by bution will also be used to improve the livelihoods of residents the Project. Regional geology is depicted in Figure 3.3. of the NBCA as well as minimise the potential for future wildlife trade and abusive harvest from the forest. Potential Local Faults Management of the NBCA is currently conducted by the District Satellite imagery indicated that folded structures forming the DepartmentofForestrywithitsheadquartersontheNakaiPlateau. Nakai syncline are repeated in the older underlying sedimentary A framework of programmes will be implemented in the NBCA rocks, including permo-carboniferous limestones. One fault was for management of the area and is discussed in the SEMFOP. These noted in the analysis, the Nam Gnouang fault, which is close to programmes include: i) forest and land use planning, allocation the Nakai Dam site (Roberts, 1996). This fault is part of a series and management; ii) biodiversity monitoring, management and paralleling the Red River Fault, which runs through central and protection; iii) village livelihood development; and iv) community southern Lao PDR. The main faults in this series are outside the and social development. Some of the programmes are currently proposed Nakai Reservoir area and there is no evidence of recent being implemented as a consequence of the initial programme activity along these faults (EDF, 1996a). Several potential faults conducted by IUCN/WCS and a continuing project known as the were observed, two of which were interpreted as faults near the District Upland Development and Conservation Project. Among Nam Kathang and the edge of the reservoir basin. These poten- the programmes that have been implemented is a programme to tial faults were investigated but did not indicate measurable dis- reduce wildlife trade within the NBCA. Seven villages are partici- placements. Another potential fault was investigated in 1995. It pating in the programme at present and all of the villages within represents the transition of bedding orientation from the tabular the NBCA should become involved in the future. Management structure of the Nakai Plateau to the steep structure of the Nam of the wildlife trade is a major component in conserving the 16 Kathang rim, and the transition does not represent faulting. Based Impacts endangered and threatened bird and mammals species known to on available information, no major faults or interpreted faults inhabit the NNT NBCA. Some of the species that will benefit from that would affect any of the Project features have been identified these mitigation measures are globally threatened, including the (EDF, 1999).Additional geotechnical work will need to be done for Asian elephant, tiger and wild dog. the dam alignment, the tunnel alignment, the Power Station and the Downstream Channel before the final design is prepared. Topography, Geology & Soils Soils Baseline The escarpment consists of well-bedded siltstone, mudstone, and fine to medium sandstone. The upper part of the formation within Dam Site which the dam is located also comprises coarse-grained sandstone and a pebbly soil horizon. In the very centre of the area lies the The geologic formation at the dam site consists primarily of sand- youngest basement geologic formation, composed of evaporite stone. The weathering of the rock has created from three to ten rocks, mainly halite with gypsum caprock when cropping out. metres of colluvium overlaying the sound rock. The integrity of Topsoils in other areas of the escarpment are stiff to hard lateritic the rock at the dam site will influence construction of the dam material (meaning highly permeable weathered material from par- and spillway sections. Some outcropping can be observed at the ent rock) of one horizon. A large portion of the basin, above the site and has influenced the actual design of the dam and spillway core area below the peaks to the northeast and edge of the escarp- structures. Some mudstone and siltstone is evident in the sand- ment, has forest cover growing in tropical soil horizons composed stone layers. These will influence the design of the dam and will ofAcrisols, and Ferralsols. Much of this area contains a higher pro- likely require a grout cut-off curtain to improve the safety of the portion of rock than soils. dam. Some jointing of the rock is evident from the surface. Alluvium deposition conditions exist in two areas in the Nakai Nakai Plateau basin. In the central part of the basin, late Tertiary deposits lie in a 38 km by 6 km band. The river meanders through this area and Geology has created a number of wetlands. This wide band of deposition The topography of the Nam Theun basin and soils are closely consists of soils that are so to very stiff, silty clays and loams. related to the geology. Shallow dipping sedimentary rocks form a Through this band, soils right along the river are more recent allu- broad synclinal basin, which trends northwest-southeast and var- vium material that consists of fine to coarse sands.Asecond area of ies from 15 to 35 km wide. Within the basin, the topography is gen- deposition exists in the sandstone area, upstream of the proposed erally gently sloping and coincidental with the bedding dip. dam site, and before the Nam Theun starts cuing down out of the Within the Project area, the reservoir area can be divided into the Plateau. Soil horizons in this deposition area contain more sand Nakai basin, centred on the Nam Theun (80 km long and 30 km and are sandy loams. wide), and the tributary Nam Malou sub-basin, on the south-west- The beer-developed soils are in the degraded gypsum area, but ern flank of the Nakai basin. These basins are structural and cor- they tend to be salty and do not drain well. Soils in the Tertiary respond to syncline structures. From the centre of the Nakai basin, deposits band do drain and have supported a limited agricultural at El 520 m to El 550 m, the ground surface rises to a line of peaks community.Thesealluviumsoilsareamixtureofloamyandsandy at between El 1,100 m and El 1,300 m along the northeast margin loam soils over loamy silts, with moderate permeability, but they of the basin. The southwest margin of the basin (and Nam Malou tend to be slightly acidic, with low to moderate fertility. sub-basin)ismarkedbyalipatEl600mtoEl700mwithsaddlesor The identified reselement areas of about 3,460 ha have soils that passes at elevations slightly less than maximum water level. This is are residual materials from weathered sandstone and mudstone. Topography, Geology & Soils 39 EAMP Main Text Age Formation Map Key Description Approx. Thickness Impacts Quaternary Unnamed Alluvium & colluvium: fine to coarse gravel & sand, silt & clay; unconsolidated to ­ poorly consolidated gravel, sands & clays As above, with higher relief remnants of Maha Sarakhan formation (described below) Unconformity Mid Cretaceous to Tertiary Maha Sarakhan Crystalline halite & gypsum; red-brown & gray clay < 150m Lower Cretaceous Khok Kruat Fine to medium grained micaceous & quartzose red-brown & gray sandstone: 600 m brown-red to brown mudstone & siltstone Middle to Upper Jurassic Phra Wihan (a) Fine to coarse-grained quartzose sandstone with pebbly to conglomeritic 1,100 m beds; light brown-white to gray to red-brown (b) Fine to medium grained quartzose to quartzlabile sandstone; green-gray to red-brown (c) Brown-red/gray-green mudstone & siltstone (commonly sideritich) Lower Jurassic Phu Kradung Brown-red/gray-green mudstone & siltstone; thinly bedded grey mudstone/silt- 400 m stone; fine to medium grained dark gray to green-gray quartzose sandstone; gray shale, purple & green marl & minor dark gray micritic limestone lenses near base Unconformity Sub-volcanic & Intrusive Complex Sub-volcanic: Phase 1: porphyritic andesitodacite, porphyritic dacite; Phase 2: porphyritic rhyolite, porphyritic trachyrhyolite; Intrusive: Phase 1: pink, porphyroid biotite granite, granodiorite (?), medium- grained biotite granite; Phase 2: aplite Upper Carboniferous to Permian Unnamed Karstic, dark gray, micritic limestone 100's m Lower Carboniferous Sandstone, gray silty sandstone, some thin interbeds of coal, beds: Calcareous, occasionally Nodular & fossiliferous, carboniferous Intrusive Complex Phase 1: porphyritic, coarse grained melanocratci biotite granite; Phase 2: Me- dium grained biotite granite, bearing cordierite; Phase 3: Pegmatite, aplite Unconformity Devonian Unnamed Gray siltstone & darg gray to black carbonaceous/calcareous shale; dark gray ­ argillaceous limestone Unconformity Proterozoic to Lower Paleozoic Unnamed Partially to strongly metamorphised sediments: thin-bedded quartz serricite schist; ­ (Ordovician) Upper Ordovician thick-bedded quartz sandstone, quartz serricite schist; Lower Ordovician Partiallt to strongly metamorphosed sediments & volcanoclastics: quartz-sericite schist, tuffaceous sandstone, with lenses of andesite & quartzitic sandstone, a little calcareous shale Proterozoic Basement complex: low to high grade metamorphic schists & gneiss Figure 3.3: Regional geology 40 Topography, Geology & Soils EAMP Main Text Most of the weathered soil is usually transported away, leaving Reaches of the Xe Bang Fai a shallow soil layer with many rock outcrops. The soils are sand- stone derived, free draining, and heavily leached. A further 1,000 Most of the lower terraces used for agricultural purposes along the ha has soils derived from sandstone, where the soils are fine sandy Xe Bang Fai, below the Nam Phit junction and above the bridge on loam over a clay loam subsurface. The soils are acidic in both lay- Road 13, are identified as Acrisols or Cambisols soils. Below the ers and are considered well suited for pasture, but moderately to bridge, more Alisols than Acrisols are found. Due to the nature poorly suited for field crops. Limitations are caused by the acidic of sediment deposition along the river banks, the soils contain nature and water deficiency, due to the moderately permeable Arenosols that are coarser than sandy loam but still have less than nature of the soil that allows water to drain away. Results of soil 35% coarse rock in all horizons.Arenosols only have an orchicAor surveys and analyses in the area of the pilot village are detailed albic E-horizon (Driessen and Dudal, 1991). in the report from the GOL Soil Survey and Classification Center Potential Impacts (2001) and summarised in the SDP with indications of the agricul- tural implications. Reservoir Induced Seismicity Headrace Channel & Surge Sha In a synthesis of worldwide available data on this topic SMEC Lookingsouthwardsalongthelayoutoftheheadracechannelfrom (1991) indicated that this risk is generally associated with the com- the centre of the Nakai Reservoir, the topography is low relief, gen- bined effect of a reservoir of over one billion m3 capacity and a tly undulating and very gently rising with dip slopes to a major dam over 100 m in height. Reservoir impoundment alters the stress gully approximately 1,350 m from the intake. Between this gully regime within the crust by increasing the shear stress due to the and the edge of the escarpment at approximately El 550 m, about weight of the water and reducing the shear strength by increasing 600mfurthersouth,thetopographyreflectstheunderlyingsteeply pore-water pressure. It is agreed that these changes are not suf- dipping strata with narrow ridges and deeply incised gullies. The ficient to create failure in unfractured rock. It is possible however, surge sha is located on the lip, formed with hills culminating at that faulted rock with a high stress level may slip as a consequence about El 550 m, which dominates the Nam Kathang and tributary ofreservoirimpoundment.TheactivestoragevolumeoftheProject valleys with steep slopes. The area surrounding the surge sha is reservoir is 3,930 million m3 with an operating range of about Impacts cut by deep thalwegs, at the boom of which can be observed steep 12.5 m. The Nakai Dam does not exceed 48 m in height and the dips that are almost vertical. maximumreservoirdepthisrestrictedtoasmallareawith an aver- age depth of 7.1 m. Although the maximum reservoir volume of Tailrace, Regulating Pond & Downstream Channel the Project exceeds the above volume criteria, the dam is small and The tailrace channel, regulating pond and a short segment of the the reservoir is relatively shallow. A theoretical approach to the downstream channel are situated in the Nam Kathang Noy valley. analysis of potential reservoir-induced seismicity also indicated The foundation for the regulating dam and the right abutment are that the most susceptible sites are those under extensive tectonic impervious mudstone and siltstone. The le abutment is an allu- activity, where vertical stress exceeds the horizontal stress. In the vium terrace with bedrock up to eight metres below the eventual Nakai Plateau area, it is likely that the maximum stress compo- pond level. Treatment to prevent seepage losses and subsequent nent is approximately horizontal and the area has a notable lack possibleerosionisplannedforthisarea.Alongthetailracechannel, of faults. The probability of reservoir-induced earthquake can be the overburden is between 10 and 15 m deep. Overburden consists considered as low, and no significant impacts are expected from of silt, clayey silt with occasional sand, and gravelly intervals. The the reservoir loads. soil in this area is relatively fertile. From near Ban That, the down- stream channel will be in a limestone formation and will require Reservoir Water Tightness treatment to maintain the water in the channel. The limestone The geological factors that could potentially lead to leakage of formations have numerous caves with potential for interconnec- water from the reservoir at El 538 m are: i) the hydraulic relation- tion among them. Southwest of Ban Gnommalat, a subterranean ship between the surface and the underlying limestone; and ii) the course was identified for the Nam Phit (Process Design Geological rim of the escarpment separating the Nakai basin and the Nam Report, Open Air Works, EDF, 1994). The karst and the fracture Malou basin from the Nam Hinboun and Nam Kathang Valleys. network of the limestone massif form an aquifer with very high permeability, which is effectively in equilibrium with the alluvium Relationship Between the Reservoir & the Underlying Limestone water table. This will result in exchanges between the two and the The geological layers forming the base of the reservoir are folded downstream channel in either direction, depending on the season sandstones,siltstonesandmudstones.Thelayersareabout2,000m and the channel discharge regime. thick; at least 1,100 m at the dam site, and include the Nam Malou Soils in the first 10 km of the downstream channel support rain-fed sub-basin. Some of the layers are typically considered watertight and irrigated paddy systems. The rest of the downstream channel formations. A 566 m adit was opened in the vicinity of the power route is primarily old alluvium common to riverbeds.Agricultural station and the power tunnel into the Plateau. The adit revealed soilsaresimilartothebeersoilsinthevalleyandhavemoresandy that the rock was 85% sandstone within 200 m of the power sta- loams and loams with moderate permeability. Soils that support tion and tunnel alignment. Investigations with respect to ground- rain-fed lowland paddy tend to be highly weathered, moderately water in the adit indicated that the estimated maximum inflow acid with a base saturation of 50% or more within 125 cm of the was approximately 0.1 l/s. The purpose of determining the rate of surface (Driessen and Dudal, 1991). Soils of the Gnommalat Plain inflow is to determine what measures need to be incorporated into typically have low clay content, low organic maer content, and the design of the tunnels and power station to prevent problems extractable acidity (soluble Al and Fe). Their low water retention within the tunnels and power station structures. The level of water capacity makes them very drought prone (Lao-IRRI, 1995). Allu- seepage from the adit indicates that there is very lile water in the vium in the area consists of over-wash sandy to silty clay soils that rock and that the sandstone will provide a watertight basin for the are somewhat poorly drained. reservoir. Topography, Geology & Soils 41 EAMP Main Text Table 3.3: Potential erosion rates Scenario Description Topsoil Loss Erosion Rate Sediment Load (mm/a) (kg/ha/a) (tonnes/a) I Current rate, strict management of the NNT NBCA 0.04 580 231,530 II Controlled land use and forestry management 0.20 2,920 1,160,000 III Uncontrolled development 2.5 36,000 14,500,000 Relationship between the Reservoir & Adjoining Catchments from uncontrolled development. The predicted sediment loads Investigations indicate that groundwater levels during the dry sea- from these three scenarios are shown in Table 3.3. son are close to the reservoir future normal supply level or a lile The density of the deposits is influenced by the particle size dis- higher (El 534.5 m and 541 m). Test pits and borings at several loca- tribution and is time dependent. Table 3.4 gives the percentage of tions requiring saddle dams indicate that foundations and abut- the total storage volume occupied by sediment under the different ments consist of clayey soils and are underlain by mudstones and scenarios. siltstones. The foundation conditions for all of the saddle dams appear satisfactory. However, additional work will be done at the At the current rate of catchment erosion, the loss of storage vol- sites prior to the design of the saddle dams. Based on the results of ume would be quite minor. The long-term reduction of reservoir these tests, it is anticipated that there will be no significant leakage storage can be exacerbated if development in the catchment is not of water through the saddle dams. properly managed (scenario III). Under scenario II, loss of storage volume aer 100 years would be around 110 million m3 or 2.8% of Erosion & Sedimentation the total volume. The "dead" storage below the MOL of El 525.5 m is 380 million m3. However, not all of the volume loss will occur Reservoir Area in dead storage and the ratio will depend on the distribution of reservoir sedimentation, as discussed below. Erosion Rates Sediment distribution in the Nakai Reservoir was estimated by The average annual sediment load in the Nam Theun was esti- SMEC (2003) and is presented in Table 3.5. mated at 231,530 tonnes by SMEC (2003) based on suspended Around 40% of the sediment deposits will sele in the live stor- Impacts sediment sampling at Ban Thalang (447 samples from 1988 age, according to computations for scenario III. This implies that if to 2002) and at the Nakai Dam site (299 samples from 1994 to sediment yield were greatly accelerated under uncontrolled devel- 2002). The Nam Theun catchment is eroding at an annual rate of opment within the catchment, loss of reservoir storage could be 58 tonnes/km2, or 580 kg/ha. This is equivalent to a top soil loss rate quite significant. Under scenario II, which can be considered as of 0.04 mm per annum. By global standards, and particularly for a possible scenario for the Project (SMEC, 2003), the reduction in tropical areas, this is a very low rate of soil loss, but is consistent power-generating capacity caused by the loss of storage volume with the largely undisturbed, natural forested environment which would be acceptably small, even in the long-term. characterises most of the catchment. Coarse sediments from tributary inflow (e.g. sand, gravel and cob- Loss of Storage Volume ble) will be deposited in the active storage of the reservoir, near Considering the capacity-inflow ratio of 0.52 (inflow of 7,527 the mouths of the tributaries, and will lead to the build up of a million m3, capacity of 3,910 million m3) and the precision of the small delta. This will aggrade a short section of tributary channel estimates of river sediment loads, SMEC assumes that all the sedi- upstream from the full supply level due to local changes in river ment load of the Nam Theun will be trapped by the reservoir. The gradient. Over time, the tributary deltas will gradually grow and loss of storage volume in the reservoir will be determined by the the beds will aggrade for some distance upstream. Water levels in incoming sediment load and the density of deposits. The sediment the aggraded reach will be higher than in the natural state. Some loads will depend on the future development of the catchment and of the coarse sediment will be in active storage, with some in the the accelerated rate of erosion from the catchment. SMEC (2003) aggradation zone and some reaching the dead storage. Some fine analysed the erosion rates of three land-use scenarios: i) Scenario I sediment (silt and clay) will be deposited in the backwater areas assumed that strict management of the NNT NBCA would main- above and in active storage indicated by the spidery configuration tain erosion rates at their current low levels; ii) Scenario II adopted of the reservoir where the tributaries enter. a higher erosion rate expected from controlled land use and for- estry management in the NNT NBCA; and iii) Scenario III adopted Provided the amount of sediment deposited in the Project catch- an erosion rate over sixty times the current rate that may result ment is near to that predicted above, the impacts described above are not of serious consequence to either the function of the reser- voir for energy production, or to environmental impact. Table 3.4: Loss of storage volume (million m3) Years of Scenario I Scenario II Scenario III Table 3.5: Sedimentation distribution in the Nakai Reservoir Operation Volume % Volume % Volume % Sedimentation Distribution (%) 10 2.3 0.05 12 0.3 118 3.0 Storage Type I Reservoir Type II Reservoir Type I Reservoir 20 4.6 0.12 23 0.6 231 5.9 Scenario II Scenario II Scenario III 30 6.8 0.17 34 0.9 343 8.8 Live storage 41 25 40 50 11.1 0.28 56 1.4 562 14.4 Dead storage 59 75 60 80 17.5 0.45 89 2.3 886 22.7 100 21.7 0.55 110 2.8 1100 28.1 Note: Type I refers to a "lake" classification and Type II refers to a "floodplain-foothill" classification (for more information refer to SMEC, 2003) 42 Erosion & Sedimentation EAMP Main Text Proposed Mitigation & Monitoring Xe Bang Fai The appropriate management of the NNT NBCAshould guarantee The Xe Bang Fai is currently eroding, with slumping visible along that measures are implemented to control erosion and sedimenta- its river banks.Atrend of widening of the Xe Bang Fai channel has tion in the reservoir and to ensure that sediment yield will remain been observed over the period 1995 to 2002 based on a comparison at the current estimated low level. From an economic and environ- of bench marked cross-sections (SMEC 2002). The river is charac- mental perspective it is important that timber harvest in the NNT terised by banks 135m to 168m apart in the reach upstream of the NBCA is eliminated and that slash-and-burn activities be limited Nam Oula confluence and generally 135m to 159m apart in the to current levels or less. The objectives of the NTT NBCAmanage- reach below the Nam Oula, although the channel width exceeds ment include activities to protect and rehabilitate the forest cover 200m in a few locations. The river bed is generally underlain by to ensure adequate water flows with low sediment to the reservoir. bedrock with a thick cover of alluvial deposits. The river bank is The management of NNT NBCA resources is discussed in more composed of fine grained alluvial material in the range of fine sand detail in the SEMFOP. to silt. Isolated locations have clayey material in the banks. There To assess whether the land use and forestry plans in the SEMFOP are rock outcrops in the banks covering about 3-4% of the river are being successfully implemented, the water quality monitoring length. The banks of the river display many areas of instability programme will analyse levels of suspended solids and sediment where slips have occurred, generally as a result of either toe scour size distribution in the Nam Theun tributaries entering the reser- and undermining, or excess pore pressures as the water recedes in voir. Monitoring during the operational phase will be expanded to the dry season. This is a natural process that is ongoing irrespec- include sediment traps throughout the reservoir, to help develop tive of the future Project. Changes in the hydrology, through both an understanding of the sedimentation processes within the res- a difference in sediment load and fluctuations in discharge, will ervoir. result in an increase in the rate of erosion whilst the Xe Bang Fai readjusts its morphology. Although the reselement area represents only a fraction of the catchment area, uncontrolled erosion will contribute to sedimenta- The total inorganic sediment load currently supplied to the Xe tion in the reservoir. The implementation of the SDP will ensure Bang Fai from upstream of the confluence with the downstream that agricultural practices and forestry activities within the reset- channel will not change significantly. However, as a result of sus- tlement area prevent such erosion. tained power station releases of water that is poorer in sediment, Impacts sand and finer sediment will be removed from the bed and bars In-Stream Degradation in the river channel below the confluence with the downstream channel. Much of the bed profile of the Xe Bang Fai is controlled Downstream Nam Theun by rock outcrops and the river winds between hills of rock forma- As most of the products of catchment erosion and other sources tions. The state of its bed and banks suggest that vertical stability of the channel is higher than its lateral stability. Its bed profile and of inorganic sediment will be deposited in the reservoir, the Nam general plan are therefore unlikely to change much. There may be Theun downstream from the dam will not receive its former sup- stretches of weaker bank where the soil is sandy and easily erod- ply of these materials. However, the low flows, which will be char- ible, while outside bends in the meandering river channel may acteristic of this downstream reach aer the dam is constructed, erode because of larger and occasional low flows. will be too small to cause erosive damage. Erosion of riverbanks in downstream sectors of the Nam Theun will not be a major problem In the review of the river geomorphology, SMEC (2002c) predicted as there are considerable lengths of rock zones present, and veg- that erosion of the riverbanks will occur, with general widen- etation will tend to encroach in other zones. The infrequent spill ing of the river channel. Higher flows of low sediment-loaded events that will occur over the Nakai Dam when the amount of water will increase the hydraulic energy for sediment transport, water coming into the reservoir is greater than the storage capacity and increased frequency of high stage saturating riverbanks and of the reservoir will have the potential to cause erosion and remove weekly drawdown during the dry season will weaken the stabil- the vegetation that will be established in the Nam Theun down- ity of bank material. Fluctuating water levels, particularly in the stream from the Nakai Dam. Results from the riparian release and dry season, will tend to increase erosion through increased pore spill study will be discussed together with adaptive management pressure while local increases in piping and tunnel erosion will of the flow and spills once the study is completed in December occur due to the drawndown. In addition, inundation of existing 2004. bank vegetation for longer periods could impact riverine veg- etation and reduce the binding effect of their roots, which would Downstream Channel further increase the rate of erosion. However, it is expected that some species might become established up the banks, assisting The first 8.5 km of the downstream channel will be lined to avoid in their long term stability. All increased rate of bank slumping erosion. Downstream of the aeration weir, the downstream chan- and channel widening may be expected over several years aer nel will be natural soil with rock protection at critical points. The diversions commence. SMEC (2002c) estimated that widening of confluence of the Xe Bang Fai and the Nam Phit will be lined to the channel could typically reach up to a maximum of 20 m during avoid erosion in this area. The situation will be monitored by the initial active period of change, although widening will occur NTPC and if it is determined that erosion is puing the structural at the same rate everywhere. In general, the size of this loss will stability of the downstream channel or the confluence area at risk, decrease as distance from the confluence with the downstream rectification works will be carried out as needed. channel increases. Loss is predicted as being negligible by the time Nam Kathang the river reaches the bridge on Road 13 (SMEC, 2002c). In 2004, SMEC conducted a further study (SMEC, 2004a) to refine this pre- Project releases into the Nam Kathang will be equivalent to natural diction on bank retreat and estimate the time it will take to reach discharges. Therefore it is expected that the quantity released will the new equilibrium. The analysis of river bank regression utilized not impact the current rate of erosion. The water discharged will several approaches that take into account the new river regime and tend to have a slightly higher capacity to carry sediment, but given tractive force of the banks. The analysis was carried out on cross the flow and lack of fluctuation, no significant increase in the ero- sections along the Xe Bang Fai, the locations of these are shown sion rate is expected. in Figure 3.4. The results of this additional study are presented in Erosion & Sedimentation 43 EAMP Main Text Impacts Figure 3.4: Location of cross-sectional survey sites on the Xe Bang Fai (water level recorded December 2002) 44 Erosion & Sedimentation EAMP Main Text Table 3.6 The revised estimate for bank regression using the river and heavy rainfalls over the Project area. However, rainfall during regime approach suggests that the average widening is 10.7m with the wet season usually exhibits a bimodal distribution, with a short an upper limit of 15.9m for the entire river. The revised estimate for dry period of one to two weeks, usually between June and July. bank regression is somewhat less for the tractive force approach, Aer this period rainfall becomes more frequent, including heavy with an upper limit of 14.6m. The additional study reconfirmed storms which result from tropical cyclones entering the region the earlier SMEC (2002c) estimation that maximum widening of from the South China Sea, mostly during September and Novem- the channel would be no more than 20m. Over time, a new cross- ber. Flooding frequently occurs when two or more of these storms sectional equilibrium that is able to accommodate the Project occur in succession or when the ITCZ, which is the forward edge waters will establish, and the rate of erosion will decrease back of the southwest monsoon, has passed into one of its more active towards existing levels. SMEC (2004a), using a Generalised Stream stages, with tropical cyclones following shortly thereaer. Tube model for Alluvial River Simulation (GSARS), estimated that A transition period, from mid-October to early November, is fol- the timeframe for a new state of equilibrium will not become estab- lowed by the dry northeast monsoon (cold season) which normally lished before two years aer the new flow regime of the Xe Bang blows from China between October and February. This season is Fai starts. The process of adjustment to the river morphology is characterised by sparse, relatively light rainfall, lower tempera- likely to be slow and obvious, giving communities sufficient time tures and humidity. to adjust without unpredicted losses to property or injury. The northeast monsoon is followed by another transition period Proposed Mitigation, Compensation & Monitoring to the hot season from March to early May, and is characterised by increasing temperatures, rainfall and humidity. The transition is Several Project components are designed and will be operated to slower than the transition from wet to cold seasons. helpminimiseanyincreasesintherateoferosionintheXeBangFai. These include: i) the retention of 8 million m3 of water in the regu- Rainfall lating pond and its controlled release to lessen water level fluctua- tions that could lead to increased pore pressure in the river banks Rainfall in the Project region is the highest that occurs in Lao PDR. and instability; ii) the operation of the regulating dam to limit the The southwest monsoon produces a warm moist airflow into the maximum rate of decrease in discharge through the downstream area from May to September, and spatial variation of rainfalls is principally affected by orographic effects. High rainfall occurs channel to 30 m3/s/hour, in order to prevent rapid drawdown and Impacts the resultant pore pressure and iii) the downstream channel/Xe Bang Fai confluence will be strengthened to prevent erosion and Table 3.6 : Predicted Width Increase in the Xe Bang Fai with Regime and will be monitored. Tractive Force Approaches To establish natural erosion rates, NTPC is currently carrying out Tractive Force Regime Approach detailed cross-sectional surveys of 29 sites on the Xe Bang Fai. Approach River Width Original This monitoring will continue during Project operations to detect Station (m) Width Width Width Width whether an increase in erosion rate has occurred. Figure 3.4 shows Revised Increase Revised Increase the locations of the cross-sectional survey sites on the Xe Bang (m) (m) (m) (m) Fai. Both remedial mitigation measures, such as bank protection 1 136 146.1 10.1 145.2 9.2 and stabilisation (in those cases where it is economic to do so for 2 167 179.3 12.3 178.3 11.3 important permanent structures or structures with community or cultural value), and asset and livelihood compensation will be 3 136.8 146.9 10.1 146.1 9.3 considered and the most appropriate measure or combination of 4 215 230.9 15.9 229.6 14.6 measures applied on a case-by-case basis by NTPC. Where build- 5 143 153.6 10.6 152.7 9.7 ing relocation is feasible, the Project will assist in the relocation 6 163 175 12 174.1 11.1 of buildings that are under threat from the increased erosion. A survey of assets along the river bank will be undertaken prior to 7 168 180.4 12.4 179.4 11.4 operations and mitigation and/or compensation will be planned 8 147 157.9 10.9 157 10 for and implemented as required. Following the start of operations 9 155 166.5 11.5 165.5 10.5 regular trips will be conducted by the Project to visually detect abnormal erosion, as well as impacts on previously identified vil- 10 154.3 165.7 11.4 164.8 10.5 lage infrastructure and livelihoods. Villagers will also be able to 11 135.1 143.5 8.4 142.8 7.7 alert the District Compensation Commiees of any abnormal ero- 12 143.1 152 8.9 151.3 8.2 sion rates or affected infrastructure and livelihoods. 13 152.9 162.4 9.5 161.6 8.7 Climate 14 140 148.7 8.7 148 8 15 135 143.4 8.4 142.7 7.7 Baseline 16 230.8 245.1 14.3 244 13.2 17 202.5 215.1 12.6 214 11.5 General 18 165 175.2 10.2 174.4 9.4 The climate of the Nam Theun and Xe Bang Fai catchments is influenced primarily by the seasonal southwest and northeast 19 207 219.9 12.9 218.8 11.8 monsoons,theIntertropicalConvergenceZone(ITCZ)andtropical 20 144.4 153.4 9 152.6 8.2 cyclone disturbances such as tropical storms and tropical depres- 21 159.2 169.1 9.9 168.3 9.1 sions. 22 147.9 157.1 9.2 156.3 8.4 The southwest monsoon (wet season) normally affects the catch- 23 169.6 180.1 10.5 179.3 9.7 ments from mid-May to early October and is predominant when atmospheric pressure is low over Asia. This is a period of frequent 24 134.9 143.3 8.4 142.6 7.7 Climate 45 EAMP Main Text Table 3.7: Mean monthly rainfall at representative stations with years of operation in parentheses (units: mm) Station Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total Ban Thalang (1987-2002) 5.3 24.6 55.3 85.4 306.6 442.8 561.2 526.4 296.7 97.3 12.3 2.8 2417 Nakai Damsite (1994-2002) 4.0 19.9 55.8 108.5 331.2 474.4 707.8 586.3 316.4 75.4 8.5 6.9 2695 B. Xoklek (1994-2002) 4.3 23.9 41.3 121.9 311.8 381.5 611.7 519.8 274.1 131.5 17.5 5.4 2339 B. Nameo (1994-2002) 11.6 14.5 28.7 14.3 202.6 240.6 470.8 594.1 287.4 313.3 41.3 16.2 1739 Mahaxai (1989-2002) 2.9 23.5 35.1 112.5 275.9 506.3 606.3 600.8 403.1 64.6 11.4 3.6 2646 Nakai Tai (1994-2002) 9.9 17.3 59.6 140.0 389.8 483.8 763.7 619.5 390.0 85.1 13.1 7.2 2979 Gnommalat (1994-2002) 0.0 21.2 34.1 110.6 245.6 400.0 578.5 497.7 293.7 35.9 4.8 1.6 2224 Nape (1922-44/1988-2002) 3.3 23.8 49.5 89.7 216.8 301.5 408.8 345.9 281.4 146.2 21.1 8.2 1896 Nakon Phanon (1953-2002) 5.1 25.8 48.8 101.7 249.2 452.6 454.0 572.6 292.8 66.9 6.5 3.1 2279 where physical barriers cause upli. The limestone precipices and in the mornings at any time of the year. Humidity data for Nakai the main escarpment along the southwestern edge of the Nakai Tai, Nakon Phanom and Thakhek are presented in Table 3.9 and Plateau provide excellent conditions for orographic intensifica- Figure 3.7. The Nakai Tai station is the most representative clima- tion of precipitation. The rugged terrain in the upper parts of the tological station located within the Project catchment. catchment acts as an additional barrier, but much of the moisture is precipitated at the first barrier.Apart from the spillover effect on Temperature the edge of the plateau, rainfall in the Nakai Plateau is likely to be Reduced temperatures are experienced from November until rather less than in the upper parts of the catchment. February, with a peak in April before the onset of the south-west Monthly rainfall analysis indicates that the rainfall in the Nakai monsoon in May. Mean temperatures at Nakon Phanom, along the Plateau is highly seasonal, with 88% of the annual rainfall occur- Mekong in Thailand, vary from 21.9° C in January to 28.8° C in ring between May and September (Figure 3.5). The average annual April, with an annual mean of 25.9° C. Data collected in the Nakai rainfall recorded at Ban Thalang between 1987 and 2002 was Plateau shows temperatures are on average about 3° C cooler than 2,417 mm (SMEC, 2003). The seasonal variation of precipitation at Nakon Phanom. Table 3.10 shows the monthly mean, average is similar throughout Southeast Asia, with approximately 92% of and extreme temperatures at Nakai Tai climatological station and Impacts the rainfall occurring between May and October. At Ban Thalang, Table 3.11 shows the monthly temperatures at Nakon Phanom 1994 and 1996 were the weest years recorded between 1987 and climatological station. Figure 3.8 shows the seasonal temperature 2001, exceeding the mean annual rainfall by approximately 30% at this site. The 1992 rainfall was the lowest recorded during the variability at Nakai Tai and Nakon Phanom climatological sta- same period at Ban Thalang, at approximately 60% of the mean tions. annual rainfall. Both 1992 and 1998 correspond with strong El Wind Speed Nino episodes. Table 3.7 shows the mean monthly rainfalls in the Project area and the station locations are shown in Figure 3.6. Pre- Winds are generally light throughout the year with an average cipitation records at other locations with a shorter length of record wind speed of 2.6 m/s at Nakai Tai, with some increase in average indicate relatively low variation in annual rainfall throughout the wind speeds during the dry season. During thunderstorm activity, drainage area for the Nakai Reservoir. The mean annual rainfall convective currents may produce strong surface winds, usually of for the Nam Theun catchment at the Nakai Dam site has been esti- brief duration. The Project catchment is at the latitude where the mated at approximately 2,800 mm per year. Over an eight-year maximumfrequencyoftyphoonlandfallsoccursalongtheVietnam period (1994-2002), the average annual precipitation at the Nakai coast (15°-20° N). These occur most oen from August to October. Dam site was 2,695 mm (SMEC, 2003). In the 14 years from 1989- Although the Annamite chain presents a barrier to such storms, 2002, the mean annual rainfall at Mahaxai was 2,646 mm, and over which usually dissipate rapidly overland, the catchment bound- the nine years from 1994-2002, mean annual rainfall at Gnommalat ary is only 55 km from the coast and records indicate that dur- was 2,224 mm (SMEC, 2003). This indicates that significant spatial ing the past 40 years, three storms have retained typhoon strength variation of rainfall occurs below the escarpment in the Xe Bang (> 118 km/h) over the vicinity of the Nam Theun catchment area. Fai catchment. Figure 3.6 incorporates the seasonal rainfall vari- ability at relevant sites, while Table 3.8 shows the recorded maxi- mum rainfall for 1-day, 2-day, and 3-day storm durations. Relative Humidity Mean relative humidity at Nakai Tai declines below 70% dur- ing the dry season, and exceeds 80% in the wet season, peaking at a mean 89% in July. Relative humidities near 100% can occur Table 3.8: Highest recorded rainfall in the Nam Theun region Rainfall (mm) Station No. of Years of Record 1-Day 2-Day 3-Day Ban Thalang 1987-2002 214 315 375 Nakon Phanom 1953-2002 459 517 545 Nape 1922-44/1988-02 356 449 500 Figure 3.5: Recorded Ban Thalang rainfall data 46 Climate EAMP Main Text Impacts Figure 3.6: Location of meteorological stations in the Nam Theun & Xe Bang Fai regions and seasonal rainfall variability for selected locations Climate 47 EAMP Main Text Table 3.9: Mean relative humidity (%) Site Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total Nakai Tai 63 64 65 60 78 86 89 87 83 79 79 68 75 Nakon Phanom 66 66 64 67 77 84 85 87 83 75 69 68 74 Thakhek 73 72 70 73 82 85 88 89 87 79 77 75 79 Evaporation Class A pan evaporation at Nakai Tai, Nakon Phanom and Vien- tiane is presented in Table 3.12 and Figure 3.9. SMEC (1991) car- ried out an estimate of the open water evaporation using the Pen- man formula, with monthly climatic data recorded at Nikhom 3 and with Class A pan data. The annual open water evaporation in Nakai Tai is estimated in the range of 1,215 mm to 1,388 mm per year. Table 3.13 shows the open water evaporation estimates for Nakai Tai, Nakon Phanom and Vientiane. Potential evapotranspi- ration is estimated to be 1,290 mm per annum. However, actual evapotranspiration losses would be less than this because of the development of soil moisture deficits during the dry season. Potential Impacts Figure 3.7: Average relative humidity Thereplacementof450km2offorest,agriculturallands,grasslands and some seasonally flooded lands with the Nakai Reservoir will result in some changes to the air temperature and relative humid- Table 3.10: Temperature at Nakai Tai (°C) ity over the water and around the shore. Averages Extremes Air & Water Temperature Month Mean Impacts Max Min Max Min During the southwest monsoon, the reservoir water is expected to January 17.3 25.1 9.6 31.2 4.0 be warmer than the air, and that trend will continue until the end February 19.7 27.6 11.8 31.0 7.4 of November. During the northeast monsoon, the air will become warmer than the water, but the difference will be small and the air March 23.0 29.9 16.0 34.9 10.5 will not able to heat the water until the end of February. Thereaer, April 26.1 33.0 19.2 36.5 15.0 the air temperature increases rapidly with the retreat of the cold May 25.5 29.8 21.1 35.0 19.0 northeast monsoon, so both air and water will experience marked June 25.0 28.3 21.7 30.6 20.0 increases in temperature. The southwest monsoon starts again in July 24.7 27.5 21.8 30.5 19.6 May, with the rainfall and runoff warmer than the mean air tem- August 24.4 27.7 21.1 31.8 19.4 perature. For eight of the twelve months, it is expected that the September 24.5 28.3 20.7 31.4 19.0 mean monthly temperatures of air and water will differ by less October 24.2 28.9 19.5 31.8 16.2 than one degree, and for six of these by less than half a degree. In November 19.4 25.4 13.4 30.7 7.2 the other four months, the difference will be 2°-3° C. Therefore, December 17.9 24.7 11.2 30.0 2.0 some change in the lakeshore temperature will occur during the Annual 22.6 33.0 9.6 36.5 2.0 southwest monsoon, but this will be difficult to notice because of the overbearing influence of the monsoon rain and its accompany- ing high humidity. Table 3.11: Temperature at Nakon Phanom (°C) Unless the water body is very shallow, it is expected that the water Averages Extremes temperature will not vary much over a period of 24 hours. How- Month Mean ever, the air temperature does and it is the differences in water Max Min Max Min and air temperature and their relative humidities that can produce January 21.9 28.7 14.7 36.1 3.1 manifestation of micro-climatic change. The climatic changes that could be conspicuous are relative humidity, wet haze, fog, cloud- February 24.0 30.4 17.7 38.9 8.0 base creation or suppression, katabatic winds, and to a lesser March 27.1 33.3 21.0 40.2 8.5 extent, precipitation enhancement. Most of these are phenomena April 28.8 34.5 23.4 42.0 13.8 that are features of some part of the hourly regime and not of a May 28.3 33.2 24.2 39.2 18.8 monthly mean. June 27.5 31.5 24.3 37.9 20.3 The overpowering presence of the southwest monsoon, its rains July 27.3 31.1 24.0 36.3 20.6 andlocallygeneratedwinds,willallowanymicro-climaticchanges August 26.8 30.5 23.8 35.0 19.0 that may occur to exist only for a short period of time. If there is September 26.9 31.0 23.4 35.6 19.6 any increase in precipitation, it will be immeasurable compared to October 26.3 31.1 21.5 35.2 13.9 the large amount that presently rains on the catchment during the November 24.4 30.1 18.5 34.8 7.8 southwest monsoon. The winds caused by the vertical convection December 22.0 28.6 15.2 34.6 4.1 will mix the lower air, preventing the establishment of differences in temperatures and humidity that could cause the formation of Annual 25.9 34.5 14.7 42.0 3.1 some noticeable micro-climatic phenomena. The concern then is 48 Climate EAMP Main Text during the northeast monsoon months when, during a daily cycle, the hourly reservoir and air temperature differences can be quite large. There is no published record of hourly temperature, relative humidity, or wind for the Nakai Plateau. But on a daily basis for example, in the yearly record simulated, the mean daily air tem- perature on the 18 February became 5.7° C warmer than the water. Conversely on the 29 May, the water temperature became 5.6° C warmer than the mean daily air temperature. The mean difference for all the days of the year is only 1.9° C, the water being warmer (Figure 3.10). Air temperatures vary widely in the dry season. On the Nakai Plateau in 1990, daily air temperature for two months ranged as listed in Table 3.14. During these months however, the reservoir will be near its lowest level and its surface only about a third of its maximum. This reduction in area mitigates the other conditions contributing to micro-climatic change. To assess the effects of the Nakai Reservoir on its surrounding climate, a general circulation model, shown in Figure 3.11, is employed. The model is valid for many situations including the development of such large features of global weather as the ITCZ. The model directs surface winds to blow from warm high pres- sure regions to cold low pressure areas. When the reservoir water is warmer than the air on the surrounding mountains, the colder mountain air flows to the reservoir. This is most likely to occur on clear nights during the northeast monsoon and in the spring tran- Impacts sitional period. If the lake surface was larger during this period, the winds would be stronger. When the reservoir water is colder than the mountain air, possible during the hoest days, the winds will be from the water upslope to the hills. Figure 3.8: Seasonal temperature variability The Nakai Plateau and its surroundings do not fit exactly into the general circulation model. The southern rim is only a hundred meters or so above the floor of the plateau, whereas to the north, the mountains rise to over 1,700 m above the floor. Also, in the south, the escarpment drops about 500 m to the Xe Bang Fai valley floor. Spill of air through the south rim will occur in its lower sec- tions. Upslope winds from the valley below to the plateau will be difficult to achieve without help from regional winds. Wet Haze & Fog Still, cool air, when combined with the presence of hygroscopic particles in the air, forms wet haze or fog near the ground or water surface, even when the relative humidity is as low as 75%. With wet haze, the number and size of the condensed droplets are both small; with fog, there are more and larger particles. On the Nakai Plateau, the presence of condensation nuclei is probably very lim- ited, as the plateau is isolated from the sea and its salt particles by mountains, and the air is relatively free of pollutants. Figure 3.9: Average Class A pan evaporation Table 3.12: Class A pan evaporation data (mm) Site Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total Nakai Tai 166 159 182 198 122 116 93 111 128 159 161 141 1735 Nakon Phanom 120 124 160 167 1656 129 125 99 111 121 122 115 1558 Vientiane 114 116 140 151 136 117 114 107 112 126 123 115 1471 Table 3.13: Open water evaporation (mm) Site Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total Nakai Tai 133 127 146 158 98 93 75 89 102 127 128 113 1388 Nakon Phanom 96 99 128 134 132 103 100 79 89 97 98 92 1246 Vientiane 91 93 112 121 109 94 91 86 90 101 98 92 1177 Climate 49 EAMP Main Text Table 3.14: Temperature variations Temperature (şC) March April Minimum 15.4 18.5 Maximum 28.6 31.7 Mean 22.0 25.1 Cloud Base Changes Suppression of the cloud base can result when the circulation pat- tern is such that there is a subsidence of air over a cooler body of water; i.e. there is a hole in the clouds over the water. Conversely, when other circulation paerns exist and warm air rises from the Figure 3.10: Relative difference between air and water temperature water, clouds can form above the lake, even in a clear sky. Hydrology & Water Resources Fog forms in different ways. When a surface is radiating its energy to the clear sky, the cooling surface then cools the air directly above it. This could happen only in areas of the reservoir where Baseline Hydrology the water is very shallow. Otherwise, the warmer water below will The operation of the Project will involve a trans-basin diversion replace the cooling water at the surface. If there is fog in the wet- lands before the Project, more radiation fog can be expected on of water from the Nam Theun to the Xe Bang Fai. Runoff from the the fringes of the reservoir when it is drawn down. Alternately, catchment area at the Nakai Dam site is on average about 7,526 warm moist air moves over cold water, the water cooling the air million m3 (SMEC, 2003), as based on the extended record from to the condensation temperature to form advection fog. In accord- 1950 to 2002. Of this amount, the reservoir will store on average ance with the general circulation model, this can happen only if the approximately 7,000 million m3 of water each year. Water stored regional winds move warm air over a cool reservoir. During the in the reservoir will be diverted through the power tunnels to the Impacts northeast monsoon, the air is generally neither warm nor moist. In Power Station and will eventually be discharged to the Xe Bang the spring transition, the air becomes hot at times but is not moist. Athird type of fog, steam fog, is formed when cold air moves over Fai. Consequently, the hydrology of three major rivers will be warm water. The cold air causes the condensation of the evapo- affected: the Nam Theun, Xe Bang Fai and Mekong. The paern of rating water. The "steam" so formed dris upwards and slowly seasonal discharge in the Mekong will change slightly as discussed disappears. The general circulation model indicates that this can in the Regional Issues section. More detail regarding the changed occur at times when the mountain air is very cold and the reservoir hydrologic relationships is presented in the following sections. water is very warm. This is most likely an early morning event The catchment areas for various sections of the Nam Theun/Nam when there is premature incursion of cold air from China and the reservoir is still in its warmer regime. Kading are presented in Table 3.15 with catchments for the major rivers of the area presented in Figure 3.12. Precipitation Enhancement & Evaporation Precipitation enhancement could only happen if dense fog forms oen and dris to the surrounding land. The fog droplets would collect on twigs, leaves, and grass. The engineering studies of reservoir evaporation and catchment evapotranspiration indicate that there will be about the same amount of water yield from the catchment both before and aer reservoir construction. That is, the evaporation from the water surface and its drawdown area is approximately equal to the evapotranspiration of the forest, river, and wetlands that it replaces. Thus, the total transfer of moisture from the catchment and reservoir to the air will remain essentially the same as before the Project. Downslope Winds Downslope winds form when the mountain air is cold and the reservoir water is warm. The cold air collects in the tributary val- leys and drains down to lower levels. The existence of warm water and cold air is not a general seasonal occurrence for the Project, as the air and reservoir water cool and warm together. If downslope winds occur now, there will be more and stronger winds with the reservoir. Upslope winds could form if the mountains were to become signif- icantly warmer than the reservoir. This is an unlikely occurrence, but if upslope winds do form, they would be limited to the lower valleys of the tributaries. Figure 3.11: General ciculation model 50 Hydrology & Water Resources EAMP Main Text Upper Nam Theun Basin Figure 3.14. Statistical analysis of the two sequences has indicated thatthemeanannualrunoffoftheextendedsequenceis1%greater Discharge at Ban Thalang than the mean annual runoff from the recorded sequence, which is River discharge is directly related to precipitation. Based on the well within the standard range of reliability (SMEC, 2003). available record, discharge in the Nam Theun has been monitored at Ban Thalang, located approximately 47 river km upstream of Discharge at the Nakai Dam Site the Nakai Dam site, since 1986, and at the Nakai Dam site since To estimate inflow at the Nakai Dam site, discharge records at 1994. Mean annual discharge at Ban Thalang for the 17-year period Ban Thalang for the period 1950-1994 were adjusted based on the 1986-2002 is 205.6 m3/s (SMEC, 2003). Figure 3.13 presents the aver- available records from the gauging station at the Nakai Dam site age monthly discharge at Ban Thalang over the recorded period (SMEC, 2003). The relationship between discharge at the Nakai along with the ranges of discharge from the actual data. Refer to Dam site and Ban Thalang was calculated using regression to Annex E for more detailed information on discharges in the Nam estimate the Nakai Dam site discharge, a factor of 1.15 needs to Theun at Ban Thalang. be applied to the Ban Thalang discharge. Based on the extended To enable evaluation of the economic feasibility of the Project, the record of 1950-2002, the mean annual discharge at the dam site is record was extended using regression techniques to start at 1950, 238 m3/s (SMEC, 2003) within a drainage area of 4,039 km2. The so providing a longer record for use in simulating the operation of estimate corresponds to a mean precipitation of 1,875 mm per year. the Project. The extension used information from the Nam Ngum In the 53 years of the extended record, 1950-2002, the mean annual Hydropower Project in Lao PDR and rainfall records at Nakhon discharge has ranged from 121.6 m3/s in 1998 to an estimated Phanom, Thailand. Based on the extended record, 1950-2002, it 382.5 m3/s in 1981 (SMEC, 2003). Mean monthly discharge at is estimated that the mean annual discharge in the Nam Theun the Nakai Dam site is illustrated in Figure 3.15, based on the at Ban Thalang is approximately 208 m3/s (SMEC, 2003). This is extended record at the Nakai Dam site. As shown in the figure, 1.2% higher than that estimated from the shorter historical record approximately 85% of annual runoff typically occurs between at the dam site and at Ban Thalang, the difference being that the June and October. Low discharge in the Nam Theun normally hydrologic record for Ban Thalang is relatively short (1986-2002). occurs in April, immediately before the wet season. Based on Recorded monthly data from 1986 to 2002 can be compared with mean daily recorded levels, average discharge in April is 31.9 m3/s the estimated data. Where there is a lack of an extended hydro- (SMEC, 2003), with the lowest average monthly discharge forApril Impacts logic record, the extension of the record has been shown to be being 25.4 m3/s, compared to an average of 734.7 m3/s in August satisfactory. Independent variables for the regression analysis (SMEC, 2003). At the beginning of the rainy season, much of the were obtained from sites with stream gauges and rainfall gauges. The monthly discharge variations in the river are illustrated in Table 3.15: Catchment areas Site Area (km2) Nam Theun at Ban Thalang 3,501 Nam Theun at Nakai Dam site 4,039 Nam Theun downstream of Nam Phao 5,249 Nam Phao 1,128 Theun Hinboun at the Theun­Hinboun Dam site 8,937 Nam Theun/Nam Kading ­ entire Catchment to Mekong confluence 14,840 Figure 3.13: Average discharge at Ban Thalang Figure 3.12: Map of catchment areas Figure 3.14: Recorded and extended monthly flows for Ban Thalang Hydrology & Water Resources 51 EAMP Main Text rainfall replenishes soil moisture depleted over the drier months Table 3.16: Flood frequencies estimates for the Nam Theun at the Nakai of the year, which explains the lag between the monthly paern of Dam site rainfall and the monthly paern of discharge. Aer the rainy sea- son there is a gradual decrease in discharge, declining through the Return period Probability of Flood Peak (years) Exceedance (%) Estimate (m3/s) dry season to April. Discharge in the river is sustained throughout the drier months from groundwater reserves until the period of 2 50.0 1835 intense rainfall returns in May. Figure 3.16 shows the annual vol- 5 20.0 2410 umes of flow estimates for the Nakai Dam site. Annex E provides 10 10.0 2780 more detailed information on discharges in the Nam Theun at the 20 5.0 3120 Nakai Dam site. 50 2.0 3560 Extreme Discharges 100 1.0 3895 500 0.2 4865 From 1985 to 2002, the average annual instantaneous maximum 1000 0.1 5520 discharge at Ban Thalang was 1,723 m3/s, with the highest flood 5000 0.02 7430 occurring in 1996 (3,054 m3/s) (SMEC, 2003). At a discharge of 3,000 m3/s at Ban Thalang, the mean velocity in the river is 1.93 m/s 10000 0.01 8490 and the river stage (or depth) is 16.2 m (SMEC, 2003). Estimates of the flood frequency, using the observed data and fiing a log Pear- this magnitude would result from a 24-hour storm that produced son type 3 distribution, are presented in Table 3.16 (SMEC, 2003). 800 mm of rainfall. The determination of the PMF is necessary to These estimates are consistent with feasibility estimates assure that the dam can withstand the maximum estimated flood (SMEC, 1991) and were based on a regional flood frequency analy- that could be produced in the basin. Table 3.17 presents the results sis for the Mekong River basin in Lao PDR (Seng, 1988). As part of analysis of extreme floods produced by PMP storms of varying of the feasibility study, an estimate of the PMF was calculated durations. (SMEC, 1991). The estimate was revised in 2001 (SMEC, 2001a) and was based on Probable Maximum Precipitation (PMP) determined During months with lile rain, river discharge is derived prima- for the area by the Australian Bureau of Meteorology. The recalcu- rily from groundwater in the catchment soils. As noted above and lated estimate was based on an alternative method for estimating based on mean daily recorded levels, the month of lowest dis- the PMF from the PMP. The revised method accounts for the non- charge is normally April, when the average discharge is 31.9 m3/s linearity of the basin's response to rainfall. The revised calcula- (SMEC, 2003) at the Nakai Dam site. The lowest discharge in the Impacts tions estimated the PMF to be 15,985 m3/s (SMEC, 2003).Aflood of period of record at Ban Thalang was 4.4 m3/s, based on mean daily recorded levels, inApril 1986 (SMEC, 2003). The mean flow for the entire month of April 1986 was 10.3 m3/s (SMEC, 2003). Nam Kathang Discharge To monitor discharge in the Nam Kathang, a stream gauge has been in operation near the site of the regulating dam since 1994. Based on mean daily water levels (1994-2002) the mean annual discharge in the Nam Kathang is 10.2 m3/s (SMEC, 2003) with a range of 5.7 m3/s to 16.8 m3/s (SMEC, 2003). Over the same period, mean monthly flow in the Nam Kathang was equal to or less than 0.3 m3/s for the months of January through to April, with the high- est average monthly flow of 38.5 m3/s being recorded in Septem- ber (SMEC, 2003). Figure 3.17 shows the monthly discharge in the Nam Kathang. Annex E contains more detailed information on discharges in the Nam Kathang. Figure 3.15: Mean monthly discharge at the Nakai Dam (extended series) Approximately 5 km downstream of the regulating dam site, the Nam Gnom, a major tributary, joins the Nam Kathang. A gauge has been operating on the Nam Gnom continuously since 1994 to measure discharge of this river into the Nam Kathang. From 1994-1998 discharge measurements were carried out and since 1998 gauge board readings have continued. Based on discharge measurements, the mean annual discharge from the Nam Gnom into the Nam Kathang is 8.9 m3/s (SMEC, 2003), thereby almost doubling the flow in the Nam Kathang just below the Nam Gnom Table 3.17: Nakai Dam site probable maximum flood estimates Duration Peak Inflow (m3/s) Volume (million m3) 24 hours 15,985 3,270 48 hours 14,250 3,625 72 hours 11,460 3,595 Figure 3.16: Annual flow volumes at the Nakai Dam site 15 days 13,855 8,720 52 Hydrology & Water Resources EAMP Main Text Figure 3.17: Monthly discharges in the Nam Kathang at the regulating Figure 3.18: Mean, minimum and maximum discharges of the Xe Bang Fai dam at Mahaxai confluence. Annex E provides more detailed information on dis- Extreme flows charges in the Nam Gnom. Despite having a larger catchment area, flow records reveal that Extreme Flows the minimum discharge in the Xe Bang Fai is consistently less than in the upper Nam Theun basin (SMEC, 2002a). Over 13 concurrent The small catchment area of the Nam Kathang at the regulating years (1989-2002), the average monthly discharge for the month of dam location means the Nam Kathang exhibits lile or no flow AprilintheXeBangFaiatMahaxaiwas12.7m3/s,withtheextreme for four dry season months a year, with an extreme monthly mini- minimum mean monthly discharge being 6.7 m3/s, as indicated by mum discharge of 0 m3/s being recorded on 67% of occasions for mean daily levels recorded in April 1993 (SMEC, 2003), compared Impacts the months of January to April. In these same months of 2002, a to an average monthly minimum of 25.4 m3/s in the Nam Theun 0 m3/s flow was observed on all occasions (SMEC, 2003). For the at Nakai Dam site (SMEC, 2003). The maximum ever recorded period 1994-2002, an extreme monthly maximum discharge of discharge in the Xe Bang Fai at Mahaxai was 3,114 m3/s in 1991 612.9 m3/s has been reported, based on mean daily level records in (SMEC, 2003). September 2000. Mekong River Xe Bang Fai at Mahaxai Stream-gauging stations on the Mekong with long-term records Discharge are located at Nakhon Phanom, Thailand, and at Mukdahan, Thai- land, opposite Savannakhet. Based on records from a stream gauge station at Mahaxai on the Xe AsseeninFigure3.19,dischargeintheMekongatNakhonPhanom Bang Fai (1989 to 2002), the average annual discharge at Mahaxai is lowest in the months of March and April, with higher flows in is 265.4 m3/s with a range of average annual discharges from the months of June, July and August. 168.6 m3/s to 335.5 m3/s (SMEC, 2003). As with the Nam Theun, the lowest flows are recorded in April with the average monthly The long-term average monthly discharges in the Mekong River flow being 12.7 m3/s (SMEC, 2003). The high discharges occur in at Nakhon Phanom over the period from 1924-1991 and Mukda- han over the period of 1922-1992 are presented in Figures 3.19 and Augustwhentheaveragemonthlyflowis921.2m3/s(SMEC,2003). 3.20, respectively. The mean annual stream flows in the Mekong Figure 3.18 presents the average monthly discharge at Mahaxai at Nakhon Phanom and Mukdahan are 5,865 m3/s and 6,960 m3/s, along with the minimum and maximum recorded discharges respectively. at the site. Field measurements of discharge have been made at Mahaxai over a range of conditions up to approximately Flood frequency estimates for the two stations, based on records dating back to the mid 1920's, are presented in Table 3.19 1,800 m3/s (SMEC, 1996). The average maximum recorded dis- charge there (1988-2002) is 2,055 m3/s (SMEC, 2003). More detailed The increase in catchment area between these two sites is 4.8%, information on discharges in the Xe Bang Fai is given in Annex E. though the increase in mean annual flood is shown as 11.2%. The mean annual flood is simply the mean of the annual maxima, so At Mahaxai, the bank full stage is approximately 15.5 m, corre- the difference between flood estimates at the two stations is exces- sponding to a discharge of approximately 2,270 m3/s (SMEC, sive given the size of the intervening drainage area. A potential 2003, 1996). Subsequent measurements have indicated that the cause for this difference is that one or both of the rating curves discharge rating curves vary from year to year (SMEC, 2002a) because of channel variations. SMEC recently updated the flood frequency analysis using 15 years of data available from 1988-2002 Table 3.18: Results of regional flood frequency analysis of the Xe Bang Fai at Mahaxai (SMEC, 2003). The results derived are presented in Table 3.18, Discharge records are also available for Bridge 13 on the Thakhek- Return Period (years) Discharge (m3/s) SMEC (2003) Savannakhet Highway. Backwater from the Mekong River influ- ences this gauge and conversion from river levels to discharge at 2 2,170 this site is difficult. However, the Mekong River Commiee has Top of bank 2,270 devised a complex discharge rating which provided an estimate 5 2,490 of the average discharge at this site at approximately 373.2 m3/s 10 2,700 (SMEC, 1991). 100 3,190 Hydrology & Water Resources 53 EAMP Main Text Figure 3.19: Discharge in the Mekong at Nakhon Phanom Figure 3.20: Discharge in the Mekong at Mukdahan for the stations are slightly inaccurate. The accuracy of discharge these aquifers from wet to dry season is in the order of 10 m.Aqui- ratings in natural streams is rarely beer than about 10% for high fers associated with the Khok Kruat formation are also recharged discharge. Consequently, the estimates may be within the normal directly from rainfall but abstraction yields are lower, at 0.05 to range of accuracy. 3 l/s. For the Maha Sarakham formation, the aquifers are recharged Long Term Trends from both direct rainfall and upward groundwater flow. Changes in water level, from wet to dry season, are less than 3 m with Trend analysis shows that the average annual discharge at Nakhon abstraction yields of less than 1 l/s. Phanom has decreased by over 10% in the past 75 years. This decrease could be a result of withdrawal of water in the upper Below the Nakai Plateau in the Gnommalat Plains, the aqui- reaches for irrigation or other uses; climatic change; or changes fers reside in the Phu Kradung formation. These aquifers are re- in vegetative cover and land use within the basin. The annual charged directly through rainfall, with water levels dropping by maximum monthly discharges in the Mekong River also exhibit 5 to 7 m during the dry season.Abstraction yields in this region are generally less than 5 l/s. Impacts a decreasing trend, indicating diminishing seasonal flood magni- tudes. On the other hand, the series of annual minimum monthly Potential Impacts discharges exhibits an increasing trend, with flow volumes in the months of lowest flow tending to increase by more than 10% over According to the current provisions and the operation of the the past 75 years. Power Station on an intermediate peaking basis, an average of approximately 222 m3/s will be diverted from the Nakai Reservoir Baseline Groundwater Hydrology through the Power Station to the Xe Bang Fai. This compares to Sedimentary rocks that outcrop on the Nakai Plateau form a three- the estimated mean annual flow of 238 m3/s in the Nam Theun at layered aquifer system. The base layer of aquifer is a 1,100 m thick the Nakai Dam site, and an average 265 m3/s in the Xe Bang Fai at sedimentary formation. Outcrops of this layer are along the higher Mahaxai. The diversion will produce major hydrological changes in the lower reaches of both rivers. The diversion of water will levels of the escarpment and form the resistant rim that surrounds impact the Nakai Plateau (Zone 1); the Nam Theun downstream the Nakai and Nam Malou basins. Below the escarpment, the of the dam (Zones 4, 5); the Gnommalat Plain (Zones 7, 8 and 9); 400 m thick layer of siltstone, mudstone and some limestone con- the Xe Bang Fai (Zones 10, 11 and 12); and the Mekong River (Zone tains a viable aquifer. The formation extends into northeastern 15). Thailand and into central Vietnam. The presence of wetlands on the Plateau indicates that water remains in the sedimentary forma- The magnitude of the hydrological regime changes is based on tions and makes its way to the rivers. Sandstones in Plateau forma- simulations of reservoir operations and energy production using tions act as the best aquifer and have the best potential for domes- the computer program EVALS. The following operating criteria tic wells. Water in the caves below the escarpment also indicates were assumed: effective aquifers. Of the three aquifer systems, the sedimentary · A minimum average riparian release of 2 m3/s to the Nam areas form the most active aquifer layers. Theun immediately below the Nakai dam; On the Nakai Plateau, in the Phra Wihan geological formation, · Hydropower generating station equipped with 4 x 250 MW aquifers are charged directly from rainfall and abstraction rates Francis turbines plus 2 x 43 MW Pelton turbines; generally range from 0.05 to 10 l/s. The change in water level in · Turbines operated up to 16 hours per day, six days per week (Monday to Saturday) to produce primary energy; · Secondary energy will be generated on demand, typically at Table 3.19: Flood frequency estimates for the Mekong River half to quarter load (secondary energy may not be generated if retention of water is needed to provide primary energy); Station Catchment Peak Discharge Area (km2) Flood (m3/s) · Minimum operating level is at El 525.5 m, power generation Nakhon Phanom 373,000 Mean Annual 25,320 was optimised for reservoir operation to meet average annual energy targets of 5,936 GWh as stated in the PPA, including 10-year 30,200 4,641 GWh per year in primary energy and 1,295 GWh per year 100-year 33,400 in secondary energy (EDF, 2000); and Mukdahan 391,000 Mean Annual 28,300 · Power generation will be reduced when the discharge in the Xe 10-year 34,100 Bang Fai approaches flood level and generation halted when 100-year 38,300 the Xe Bang Fai is at or above 15.5 m at the Mahaxai gauge. 54 Hydrology & Water Resources EAMP Main Text Nakai Plateau The Nakai Reservoir will impound approximately 195 km of the Nam Theun and its major tributaries (Nam On, Nam Noy and Nam Xot) upstream from the Nakai Dam site. This region will be converted from a river environment to a lake-like condition. Water discharged from the main stream and tributaries will be stored in the reservoir and will be diverted to the Power Station to gener- ate energy. The Nakai Reservoir will be operated on an annual basis with the FSL at El 538 m. The MOL of the reservoir will be at El 525.5 m. Within this range of drawdown, the reservoir at FSL will have a surface area of 450 km2, and at its minimum level the water surface will be approximately 82 km2. When the reservoir is at FSL, the average depth of the reservoir is 7.1 m. When the reservoir is at its MOL, some of the Nam Theun will flow within its banks. Converting the river to a lake environment will have a major impact on fish populations in the river, as discussed later in this chapter. In most years the Nakai Reservoir level fluctuates between a mini- mum level a lile above MOL, to a maximum level that varies, but is usually below FSL. Figure 3.21 illustrates water levels and sur- face area throughout the year. On average the annual draw-down is predicted to be only 6 m, which would result in a drawdown area of 15,900 ha. The drawdown zone offers potential for the establishment and management of aquatic and other plant spe- cies for supplementary forage. This forage will be available during Impacts the mid to late dry season as the reservoir levels drop, and would provide a valuable contribution to the rations of livestock in the reselement area. The management of supplementary forage is discussed further in the SDP. Given that the chosen water source for the reselement irrigation schemes is the Nakai Reservoir, the annual drawdown of the reser- voir will have to be considered during the establishment of the irri- gation scheme for each of the reseled villages. To accommodate water at MOL the sump bed level of the pumping station sump will be at El 524 m. Nam Theun Downstream From the Dam & Nam Kading (Zones 4 & 5) The minimum release from the Nakai Dam will be 2 m3/s, as aver- aged over a week during non-spilling periods. At times, the dis- charge will increase when maintenance or operation of the gates is required. During exceptionally wet years, spill will occur through the gates of the dam. Of 47 years used in the analysis of reservoir operation, spill through the gates will only occur in 18 years, when inflow into the reservoir is in excess of the storage capacity of the res- ervoir. The highest spills will occur in August as reflected from the annual hydrologic records presented above. For those years when spills do occur, the average spill during the peak of the wet season will last approximately 5 weeks, and will spill a total of 1,186 million m3. The potential impacts of the spill and riparian release will prima- rily affect fish populations but will also affect wildlife and plant communitiesassociatedwith the river course,asdiscussed in more detail later in this chapter. This portion of the Nam Theun includes the confluence of the Nam Phao downstream to the Theun Hinboun diversion reservoir. At the confluence of the Nam Phao, the Nam Theun will substantially increase in discharge. The average inflow from the Nam Phao is shown in Figure 3.22. The discharge records for the Nam Phao are from 1995-2002, with some years not complete. The discharges are estimated from the Theun Hinboun inflow Figure 3.21: Nakai reservoir levels record and adjusted from the hydrologic record at Ban Thalang, Hydrology & Water Resources 55 EAMP Main Text using a ratio of drainage areas. During March andApril, discharge in the Nam Theun downstream of the Nam Phao will be approxi- mately 7 m3/s, plus the riparian discharge of 2 m3/s from the Nakai Dam. The drainage area between the Nam Phao confluence and the Theun Hinboun dam is approximately 3,812 km2. In the reach between the confluence of the Nam Phao and the Theun Hinboun headpond, discharge will average approximately 215 m3/s. During September, the average discharge is as high as 802 m3/s. The Theun Hinboun Project is, like the Nam Theun 2 Project, a trans-basin project. In the case of the Theun Hinboun, water is diverted from the Nam Theun to the Nam Hinboun, via the Nam Hai. The impacts from the reduced flows in the Nam Theun between the dam site and the Theun Hinboun dam will affect vegetation and wildlife. No villages are present between the Nakai Dam and the confluence of the Nam Phao, although limited fishing has been Figure 3.22: Monthly discharge in the Nam Phao (only mean values avail- observed in this reach. The riparian release study will provide able from June ­ September) information on community use of the Nam Theun downstream of the Nakai Dam. As mentioned in Chapter 2, the Downstream Channel will be Downstream from the Theun Hinboun Dam, the Nam Theun designed to convey a maximum discharge of 330 m3/s plus addi- becomes the Nam Kading. The low flow in this reach will be that tional inflow from the surrounding basin up to the two-year flood amount passed through the Theun Hinboun dam plus the amount event.Floodsinexcessofthetwo-yearfloodeventwillcauseflood- pickedupfromlocaltributaries,whichhaveacombinedcatchment ing of land adjacent to the Downstream Channel, as is currently area of 5,713 km2. The Theun Hinboun Project has commied to a the case. In such conditions, when the Power Station will not be minimum release of 5 m3/s into the Nam Kading. As a result of the generating and therefore will not be discharging, the Downstream Nam Theun 2 Project, the average number of days that the Theun- Channel may actually improve drainage of the adjacent land. Hinboun will be limited to the minimum riparian release into the The Downstream Channel will include a tunnel of approximately Nam Kading will increase annually from 120 days to 175 days. Impacts onekilometreinlengththroughalimestonepinnacle.Immedi-ately Other tributaries downstream from the Theun Hinboun dam will upstream from the tunnel, an emergency spillway will be installed increase the discharge in the Nam Kading. Currently, minimum to enable relief of the water in the channel to the Nam Phit, which discharge in the Nam Kading at its confluence with the Mekong is estimated to average approximately 41 m3/s in April each year. would be the normal route for such floodwaters. The use of this spillway will be on an as needed basis when floods exceed the two- The Nakai Reservoir will have a significant effect on floods imme- yearlevel.Theemergencyspillwaywillenablewatertobereleased diately downstream of the Nakai Dam, retaining them completely from the Downstream Channel to prevent backwater effects in the in29ofthe47yearssimulated,andaenuatingthemintheremain- channel upstream from the tunnel, and will prevent damage due ing years. In general, flood peaks immediately downstream of the to overtopping of the Downstream Channel. dam will be much lower. The impact of the Nakai Dam on down- stream floods is to be included in a review of the riparian release, AfurtherconsiderationistheconfluenceoftheDownstreamChan- which will be conducted in the dry season of 2004. An outline of nel with the Xe Bang Fai. Discharge to the Xe Bang Fai may cause the approach to be taken for the analysis is presented later in the backwater effects at the downstream end, particularly during the chapter. The findings of the review will be incorporated into the wet season when discharge in the Xe Bang Fai is at or near flood analysis. conditions. The confluence area will be protected with rip-rap where the downstream channel joins the Xe Bang Fai. Monitoring Regulating Pond, Downstream Channel & Gnommalat Plain of the channel will be conducted by NTPC and any observed ero- Diverted water from the Nakai Reservoir will be channelled sion that threatens the structural stability of the confluence will be throughthePowerStation.Fromthere,thewaterwillbedischarged to a regulating pond. Operation of the Power Station is described in Chapter 2. The increased discharge from the Power Station will fill the Regulating Pond and during off-peak hours the water level in the Regulating Pond will decrease. Although the actual opera- tional details of the Power Station are not yet completely known, Figure 3.23 presents an indication of what would happen if the Power Station is operated to provide 50 percent secondary energy in addition to normal primary energy loads. The purpose of the Regulating Pond is to minimise the discharge fluctuations from the Power Station and release the water to the Downstream Channel at a more or less constant rate. Based on Figure 3.23, discharge to the Downstream Channel during the dry season will be approxi- mately275m3/sforthisscenario.Themajorimpactoftheoperating curve is that on Sundays, the discharge from the Regulating Pond will decrease down to approximately 80 m3/s. This will impact the discharge in the Xe Bang Fai at the end of the Downstream Chan- nel. In other scenarios, the discharge to the Downstream Channel Figure 3.23: Regulating Pond inflow and discharge when generating 50% could be as lile as 30 m3/s. secondary energy 56 Hydrology & Water Resources EAMP Main Text mum Project discharge (330 m3/s) will increase the water level in the Xe Bang Fai at Mahaxai by up to 5.8 m. The increases in height resulting from the Project will be less in the wet season, with an average of only 1.5 m for the month of August. The estimated mean increases in water level of the Xe Bang Fai at Mahaxai are presented in Table 3.21 while Figure 3.25 illustrates the increase in water level for the indicative secondary energy generation sce- narios presented in Table 3.20. One important consideration in the analysis of hydrologic impacts to the Xe Bang Fai is the potential for causing additional flooding in the upper and middle regions. At the Xoy Gorge, the channel narrows considerably and creates a hydraulic control, separating the upper Xe Bang Fai region from the middle. Currently flooding occurs first in the upper and middle Xe Bang Fai at Mahaxai, when Figure 3.24: Discharge rate of Regulating Pond for different secondary en- discharge in the river exceeds 2,270 m3/s. Restrictions on outflow ergy levels. fromtheregulating damwillbeginwhenflowintheXeBang Fai at Mahaxai approaches 1,970 m3/s, and outflow from the regulating corrected. The potential for erosion of the Xe Bang Fai channel is dam will cease before the natural flow reaches 2,270 m3/s, thereby discussed in more detail earlier in the chapter. preventing any additional flooding. For more information on the mitigation strategies to be adopted by the Project, refer to the sec- Hydrologic Changes in the Nam Kathang tion on mitigation below. The Project intends to monitor inputs into the Regulating Pond, Storage capacity in the regulating pond is insufficient to maintain and to release into the Nam Kathang a discharge equivalent to its regulating dam discharge at a constant level during the period natural flow. Because the hydrology of the Nam Kathang remains of reduced generation, which starts on Saturdays and continues Impacts unaltered, no hydrological impacts are expected to result from the through Sundays. Consequently, the discharge in the downstream Project. This also means the Nam Kathang will continue to experi- channel could be as lile as 30 m3/s when the Power Station is not ence its normal flood regime. operating, an amount of water which would then reduce the flow Hydrologic Changes in the Xe Bang Fai in the Xe Bang Fai. The lower discharge in the river will pass pro- gressivelydownstream.Thefluctuatingwaterlevelscausedbythis The diversion of an estimated annual average of 220 m3/s to the reduction in discharge, and the increased discharge as the Power Xe Bang Fai will have impacts to the river and communities resid- ing along it. The most noticeable changes will occur in the upper Station begins to operate, will contribute to increased erosion of reaches of the river, directly downstream of the confluence with the Xe Bang Fai channel. A detailed discussion on the potential the Downstream Channel, while lesser impacts are expected fur- change in morphology of the Xe Bang Fai and the resulting impli- ther downstream. cations, including impacts on both the fish population and human communities residing next to the Xe Bang Fai channel, is presented Upper Xe Bang Fai elsewhere in this chapter. The Upper Xe Bang Fai will exhibit most of the impacts associ- There are direct social implications for the new discharge regime ated with diversion of discharge from the Nam Theun. The Project in the Xe Bang Fai. Seasonal river bank gardens currently estab- will almost double the annual flow in the Xe Bang Fai as meas- lished by communities will be affected by both the increased water ured at Mahaxai, from 8,370 million m3 to 15,370 million m3. Aver- level and the erosion. Communities living along the Xe Bang Fai aged over the entire year, this represents a Project discharge of will no longer be able to use their current methods of crossing the approximately 220 m3/s into the Xe Bang Fai. However, discharge is expected to vary over the seasons and over the week to reflect river in the dry season, i.e. temporary bamboo bridges, and walk- power demand. Table 3.20 shows indicative minimum and maxi- ing across rapids or shallow areas. mum discharges throughout the year, depending on the amount of secondary energy being generated. Figure 3.24 illustrates the Table 3.20: Indicative minimum and maximum Regulating Dam discharges weekly hydrograph for these generation scenarios. The maximum for a percentage of secondary energy generated. discharge into the Xe Bang Fai will be 330 m3/s, while the guaran- teed minimum discharge is 30 m3/s. This minimum discharge will Month Season Secondary Minimum Maximum Energy Level % Discharge (m3/s) Discharge (m3/s) be maintained for up to 32 hours during Power Station shutdown. The impacts will lessen further downstream from the Downstream January Dry 25 47 243 Channel confluence as the catchment area for the Xe Bang Fai February Dry 50 77 275 increases and the natural discharges become higher. The increased March Dry 75 76 303 average discharge will be approximately ten times the current April Dry * average discharge in the Xe Bang Fai during the months of Decem- May Dry 50 77 275 ber through April. June Wet 75 76 303 The additional water entering the Xe Bang Fai will result in an July Wet 100 70 330 increase in water level. The impacts on water level are expected to August Wet 100 70 330 be greatest at Mahaxai, the first major selement downstream of September Wet 100 70 330 the confluence with the Downstream Channel. October Wet 75 76 303 Throughout the year the impact on water level will be more promi- November Dry 75 76 303 nent in the dry season. In the dry season, the addition of the maxi- December Dry 50 77 275 Hydrology & Water Resources 57 EAMP Main Text Middle Xe Bang Fai Approximately 34 km downstream of Mahaxai, the Xe Bang Fai passes through a range of limestone mountains, called the Say- phou Xoy Ridge. The narrow and steep grade through the rock essentially isolates the Upper Xe Bang Fai from the Middle Xe Bang Fai. In the absence of other developments, the low flow in the Xe Bang Fai at Road 13 Bridge will increase by the same amount as at Mahaxai i.e. 220 m3/s averaged over the entire year. Impacts in this zone are similar to impacts already discussed for the Upper Xe Bang Fai, however, the impacts will be progressively mitigated as tributary inflows occur down the river. In the dry season, during periods of low flow in the Xe Bang Fai at Road 13 Bridge, the maxi- mum Project discharge of 330 m3/s will increase the water level by approximately 3.5 m. However, the precise change in water level is largely dependent on the level of water in the adjacent Mekong, Figure 3.25: Water height in the Xe Bang Fai (Mahaxai) Pre & Post Nam and therefore any prediction in terms of water level increase can Theun 2. only be approximate. It is likely that the increased discharge will result in some erosion Xe Bang Fai area two mathematical models were constructed by of the river channel as the river comes to an equilibrium with the SMEC, a hydrologic model of the whole Xe Bang Fai up to the new discharge regime. As with the upper Xe Bang Fai, monitoring Mekong, and a hydraulic model of the Mekong and of the Lower of the stream banks along the river is necessary to determine if Xe Bang Fai (SMEC, 2004). A number of surveys were carried out people living along the river are adversely affected. Communities to collect data on river cross-sections, floodplain topography, river living in close proximity will experience simular impacts as those bankprofilesandfloodcontrolstructuresforinputtothehydraulic outlined for the upper Xe Bang Fai. model. The hydrologic and hydraulic models were calibrated and Lower Xe Bang Fai verified using the data recorded for floods that occurred in 1994, 1995 and 2000 for which records were readily available. Flood fre- Background: The region of the Xe Bang Fai between the Road 13 quency analysis carried out on the historic flood records of flows bridge and the Mekong River is referred to as the lower region and levels recorded on the Mekong and Xe Bang Fai during other Impacts of the Xe Bang Fai. Discharge in this region will be increased by investigations (SMEC, 1996 and SMEC, 2004a) were utilized to approximately 220 m3/s, as averaged over the entire year. Under determine the appropriate design flood conditions in the Mekong normalconditions,thisareaisfloodedeveryyearduetobackwater to be applied in conjunction with flood events in the Xe Bang Fai, effects of the Mekong and flooding in the Xe Bang Fai. According for the assessment of design flood cases. to the 36-year hydrologic record obtained at Road 13 Bridge, the Xe Bang Fai flooded in 31 years ­ without any supplemental dis- The results of the SMEC report have to be considered as a worst charge from the Project. Because the Project will affect discharge case scenario as the release of water from the regulating pond will of water from the Nam Theun/Nam Kading into the Mekong, it be stopped before the natural flow reaches 2,270 m3/s at Mahaxai, is estimated that there will be a fall of about 15 cm in the Mekong thereby preventing any additional flooding caused by the Project. during flood events (SMEC, 1996). This should allow for quicker Overall results of the SMEC modeling: The main results of the drainage of the lower Xe Bang Fai during times of flooding, and hydraulic model are as follows: A release of 315 m3/s will increase consequently partially offset the impact of the increased flows in by 3.75% the extent of the area flooded when added to the maxi- this portion of the river. mum flood flow allowed in the Xe Bang Fai immediately before SMEC hydrological modeling: In order to quantify the impacts discharges from the Regulating Dam are reduced. Figure x shows of the Project discharge on the existing flood regime in the lower the increased extent of the flooded area, from 324 km2 without the Project to 335 km2 with a project discharge of 315 m3/s. The flood levels in the river and floodplain are expected to increase by Table 3.21: Water level increases in the Xe Bang Fai at Mahaxai approximately 0.5, 0.4 and 0.2 m in the upper, middle and lower Approx. Change in Approx. Change in reaches of the lower Xe Bang Fai respectively when combined with Average pre-NT2 Elevation at Mahaxai Elevation at Mahaxai floods exceeding the bankfull flow. Velocities in the river channel Month Monthly Discharge with Maximum with Average at Mahaxai (m3/s) Project Discharge Project Discharge are expected to increase by 20% along the Xe Bang Fai for a 1 year 330 m3/s (m) 220 m3/s (m) ARI flood that is confined within the banks, and up to 7% for the over-bank floods. The hydraulic model showed that the duration January 25.0 5.2 4.2 of overtopping of the flood levees was increased on average by 3.6 February 17.6 5.6 4.6 days each year. March 13.3 5.7 4.8 Quantification of the impacts: The results of the SMEC study were April 12.7 5.8 4.9 then further analysed in terms of impacts on agricultural lands May 40.3 4.3 3.4 only. June 244.3 2.7 1.9 July 655.8 2.0 1.4 It was considered that the areas under more than 1 m of water August 921.2 1.5 1.1 during the 1.6 ARI flood events, without the additional release September 693.9 2.0 1.4 from the Project, will not be further impacted in terms of agricul- tural production, as, even without the additional release from the October 230.4 2.7 1.9 Regulating Pond, they are already under too much water to allow November 106.6 3.4 2.4 such production. The focus is therefore put on the areas that are December 41.6 4.2 3.3 currently subject to a flood of less than 1 m, and represented on Mean 265.4 2.6 1.9 Figure 3.26 58 Hydrology & Water Resources EAMP Main Text Impacts Figure 3.26: Maximum flood depths in the lower Xe Bang Fai for the 2.6 year ARI Even in Mahaxai (pre-Project) Hydrology & Water Resources 59 EAMP Main Text Impacts Figure 3.27: Impact of Powerhouse Discharge of 315 cumecs on Flood Extents in Lower Xe Bang Fai for 2.6yr ARI event in Mahaxai 60 Hydrology & Water Resources EAMP Main Text The model indicates that 3,820 ha of land will be put under more will on average further reduce the discharge by 82 m3/s. Conse- than one meter of water because of the additional release of 315 quently, between the mouth of the Nam Kading and the mouth of m3/s for an average duration of 3.6 days per year. The agricultural the Nam Hinboun, discharge in the Mekong will be reduced by an production on these areas might be impacted. average 302 m3/s. Downstream from the mouth of the Nam Hin- Inadditionthemodelindicatesthat1,540haoflandwillbeflooded boun, discharge in the Mekong will be reduced by an average of during an average of 3.6 days per year when they are not without 220 m3/s. At the mouth of the Nam Hinboun discharge from the the release from the regulating dam. However these areas will be Theun Hinboun power station will return the 82 m3/s back to the under less than 50 cm, therefore not threatening rice paddy pro- Mekong River. However, the replacement of the Nam Theun dis- duction. The extent of the areas is shown on Figure 3.27 charge to the Mekong will not occur until the discharge is returned In addition, it is possible that the extended duration of the flood to the Mekong at the mouth of the Xe Bang Fai. During the wet event on average by 3.6 days per year, could put at risk some of seasons, the reduction in discharge in the Mekong will probably the 2,497 ha of land, which will be under a depth of water varying not be noticeable. However, during the dry season, there could from 0.75 m to 1 m if the flood takes place before the paddy has be some reduction in water level. Downstream from the mouth of been able to grow sufficiently in height. the Xe Bang Fai, discharge in the Mekong will be augmented, par- ticularly during the dry season (an average increase of 220 m3/s). The current use of the land will have to be confirmed as being pro- Figures 3.28 to 3.32 illustrate the change in the monthly discharge ductive agricultural land during the rainy season. for the impacted rivers in the Project area. Detailed hydrologi- The increased flood plain created because of the additional release cal data for the water balance in the Project area is available in of water could impact positively fish production in the area. Annex E. Mitigations measures: Several measures could be considered to Groundwater mitigate the impacts: · Optimisation of the use of the existing irrigation schemes, Groundwater exists in all Project zones, and will continue to serve including the timing of the opening/closure of the various its present function of providing domestic water to communities. gates. Reduced amounts of water in the Nam Theun below the Nakai · Use of rice varieties that are tolerant to flood episodes, in terms Dam are not expected to significantly affect the volume of ground- of duration of flood and depth of flood. water in ground formations beside the river. Steep valley sides Impacts · Development of two dry season crops. mean there can be lile recharge to groundwater from the river. · Development of fisheries production. Flows in the downstream channel will increase groundwater lev- · Raising the height of the existing dykes along the lower Xe els in the Gnommalat Plain and other contiguous areas, and will Bang Fai. prove beneficial for local water supply. The SDP presents with further details the villages that are located Additional flows from the Project in the Xe Bang Fai will increase in this area, and the proposed mitigation measures that are parts groundwater levels adjacent to the rivers. Increases would be most of the Xe Bang Fai overall strategy notable in the dry season, when the Nam Theun contributions would proportionally be largest in terms of the total discharge to Mekong River the rivers. It is difficult at this time to quantify precisely how much The reach of the Mekong between its confluence with the Nam groundwater levels may increase by, but they will tend to reflect Kading and the confluence with the Xe Bang Fai, including the the average rise in the river level itself. This increase will reduce adjacent floodplain, will be affected by the combined diversion energy requirements (electrical or human labour) for removing of the Nam Theun 2 Project and the Theun Hinboun Project. water from wells along the Xe Bang Fai. Reduced flows will occur year-round, except during times when The creation of the Nakai Reservoir will also increase groundwa- the Nakai Dam spills and when flows would be similar to existing ter levels on the Nakai Plateau. The amount of increase will vary levels. Over the year, the average reduction in flow between the according to the reservoir surface level but will tend, like the Xe Nam Kading and the Nam Hinboun confluence will be 302 m3/s Bang Fai, to reflect the average rise in the water body itself. and the average reduction in flow between the Nam Hinboun and the Xe Bang Fai confluence will be 220 m3/s. Below the Xe Bang Proposed Mitigation Measures, Enhancements & Fai/Mekong confluence, the discharge in the Mekong River will be Compensation generally supplemented during the entire year as a consequence of the operation of the Project. Flooding Water Balance Among the Affected Rivers The major mitigation measure is in the operational management of Diversion of water from the Nam Theun to the Xe Bang Fai will the Project, whereby diversion of water to the downstream chan- change the hydrologic regimes of three rivers: the Nam Theun­ nel and the Xe Bang Fai will be reduced during periods when over- Nam Kading, the Xe Bang Fai and the Mekong. Storage of water in bank flooding is imminent, and shall be completely ceased prior theNakaiReservoirwillaffectdischargeintheNamTheun(known to actual overbank flooding. These arrangements are designed so as the Nam Kading downstream of the Theun Hinboun Project) that discharge from the Project will not increase the natural over- and the Mekong River. The most significant effect will be in the bank flooding, in terms of depth or frequency of flooding along the Xe Bang Fai, the receiving river for the diverted discharge from upper and middle sections of the Xe Bang Fai. the Nam Theun. The discharge in the Nam Theun downstream Based on studies to date, it is known that overbank flooding first of the dam will be dramatically reduced because of storage of occurs in the Xe Bang Fai upper and middle sections at Mahaxai, water in the reservoir. The storage of water in the Nakai Reservoir when discharge in the river exceeds 2,270 m3/s. Consequently, will also reduce the discharge of the Nam Kading to the Mekong outflow restrictions and cease generation obligations refer to dis- River. The major decrease in discharge to the Mekong River will charge measurements at Mahaxai. Average frequency of overbank be between the mouth of the Nam Kading and the mouth of the flooding at Mahaxai is approximately one in 2.3 years. Nam Hinboun. The Project will reduce the discharge in the Nam Outflowrestrictionsfromthe regulating damwillbegin when flow Theun by an average 220 m3/s, whereas the Theun Hinboun Project intheXeBangFaiatMahaxaiapproaches1,970m3/s,anddischarge Hydrology & Water Resources 61 EAMP Main Text Impacts Figure 3.28: Water Balance monitoring points, showing pre-NT2 operation flow levels (A-L;P-Q) and predicted NT2 Power Station discharge (M-N) 62 Hydrology & Water Resources EAMP Main Text Impacts Figure 3.29: Water Balance modelling pre- (Top) & post- (Bottom) NT2 Figure 3.30: Water Balance modelling pre- (Top) & post- (Bottom) NT2 operation total yearly flow operation mean yearly flow Hydrology & Water Resources 63 EAMP Main Text Impacts Figure 3.31: Water Balance modelling pre- (Top) & post- (Bottom) NT2 Figure 3.32: Water Balance modelling pre- (Top) & post- (Bottom) NT2 operation dry season (April) monthly flow operation wet season (August) monthly flow 64 Hydrology & Water Resources EAMP Main Text from the regulating dam will cease sufficiently before the flow in In terms of social impacts, it is likely that villagers will be able the Xe Bang Fai reaches 2,270 m3/s at Mahaxai. This discharge must to adjust the position of their riverbank gardens to the new water stop before the Xe Bang Fai overflows its banks at Mahaxai so that level by relocating their plots further up the bank. Where it is not flows from the Project do not worsen natural overbank flooding feasible or productive, NTPC will assist in re-establishing garden- of the upper and middle Xe Bang Fai. Travel time for diversion ing activities. NTPC will determine the potential impact of the discharge from the regulating dam to the Xe Bang Fai is approxi- Project by means of: i) baseline socio-economic surveys; ii) a study mately seven hours. An additional travel time of approximately of river gardens in each village, in terms of "gardening system", three hours is required from the downstream channel confluence tenure and income or food productivity to be undertaken 2 years with the Xe Bang Fai to Mahaxai. These travel times shall be an prior to COD; and iii) consultation with villages. Following COD, integral component of planning restriction and cessation of flows and if required by a particular village, a study will be undertaken in order to prevent overbank flooding at Mahaxai. On the basis to assess the actual effect on riverside gardens. of records available at Mahaxai (SMEC, 1996), discharge restric- tions are likely to be triggered about once per year on average, but The weekly drawdown of the water level in the Xe Bang Fai will this will depend on the outcome of further studies to determine require adjustments to the current irrigation system that uses float- appropriate trigger levels. The above measures will substantially ing pumps aached to the supply pipes. The Project will assist mitigate the flooding impact of the diversion into the Xe Bang Fai. with all pumping installation adjustments that are required due to increases in water level fluctuation. In monetary terms, this mitigation measure implies an average reduction in generation of 44 GWh/year, which is equivalent to a Since the increased water level in the Xe Bang Fai will prevent loss of approximately US$ 1.8 million per year or US$ 10 million in some of the temporary modes of crossing the Xe Bang Fai in the Net Present Value over 25 years of operations (EDF, 2000b). dry season, the impact on such access needs to be determined. A study will investigate objectives, means and infrastructure used To facilitate the actual implementation of the above arrangement, to cross the Xe Bang Fai and tributaries, and the seasonality of the following reviews and actions are recommended. During the such access. Following the study, a prediction of the impact can be construction and operation phases, the provisions for restricting made. NTPC has commied to the purchase of additional boats for outflows from the regulating dam during flood events will need to be further reviewed, as additional hydrological data becomes the concerned villages. The indicative costs, and the mechanisms available, and as portions of the Xe Bang Fai channel enlarge over for compensating communities for any losses or impacts on liveli- Impacts time and discharge capacity increases. During the construction hoods resulting from additional discharges in the Xe Bang Fai, are phases, such reviews and actions should include the following: presented in the SDP. i) additional comparative analyses of flow response in the down- Enhancements stream channel and flood rises in the Xe Bang Fai as it approaches bank full level; ii) further hydraulic analyses of the Xe Bang Fai The main enhancement resulting from the Project is the improve- downstreamofthedownstreamchanneltodeterminelevelsdown- ment of the potential and economics for irrigated agriculture river for a range of river flows; to compare those levels with river development through the provision of an increased and guar- bank heights, and then establish the incremental effects of addi- anteed water resource in the Xe Bang Fai during the dry sea- tional flow from diversion operations. This analysis will provide son. Because the Xe Bang Fai floods almost every year, resulting confidence that there will be no aggravation of downstream flood- in damage to wet season crops, communities are trying to move ing impacts, and will assist in refining flood control procedures; towards dry season irrigation and the food security it provides.As iii) prior to commencing operation of the power station, installa- outlined above, the additional water from the Project will provide tion of a telemetered data acquisition system for real time moni- a greater irrigation potential in the dry season. Throughout the Xe toring of rainfall and river levels, at and upstream of Mahaxai, to Bang Fai there will be potential to irrigate larger areas because of enable flow to be monitored remotely at the Power Station and at the additional 7,000 MCM of water available. The benefits from the the EGAT NCC. The data collected from this system will facilitate additional water are potentially greater for the upper and middle management of water releases from the regulating dam; and v) a Xe Bang Fai communities, where their pumps currently run dry review of hydrological information collected prior to and during during the dry season. the construction phase. Another beneficial consequence of the additional Project discharge During the operating phase such reviews and actions should is a reduction in pumping head, or the distance that that water include the following: i) collection of hydrological data using the must be lied vertically from the Xe Bang Fai. This reduction in telemetered data acquisition system installed during the construc- pumping head should significantly reduce pumping costs.Analy- tion phase, in order to ensure that the operation management sys- sis estimates that the potential average saving that can be made in tem of the regulating dam for flood control is based upon a maxi- the dry season is greater than 28% from Mondays to Saturdays and mum sample of available hydrographic data; ii) during potential a significant 16% on Sundays. flood periods, discharge will be physically monitored at Mahaxai, In the dry season, the increased height of water in the Xe Bang by personnel with direct communication links to the power sta- Fai will make river transportation easier, as rocks and rapids that tion; and iii) review the effects of the proposed flood control oper- are currently exposed by low water levels may be covered. Thus, ating procedures on the Xe Bang Fai to determine if any residual navigation along the river and access to villages by boat will be adverse impacts occur down the river. improved. Water Levels Riparian Release To mitigate against any rapid increases in water level, the regu- lating dam will limit the rate of increase in discharge to a maxi- The Project will result in a reduction of flow in the Nam Theun mum of 20 m3/s/hour. This represents an increase in water depth and Nam Kading downstream of the Nakai Dam. In 2004, Kellogg, of approximately 0.5 cm/min in the downstream channel and Brown and Root (KBR) were commissioned by NTPC to (i) qualify 10-20 cm/hr in the Xe Bang Fai. This controlled rate of change will and whenever possible quantify environmental and social impact ensure people and animals have time to leave the area and are not associated with the reduction of flow; and (ii) suggest operational in danger from rapidly raising water. procedures for the riparian release and complementary discharge Riparian Release 65 EAMP Main Text Table 3.22: Effect of Riparian Release on Flow Rates Downstream of the Confluence with the Nam Phao Month Nam Theun Natural Flow Nam Phao Nam Theun Natural Flow Down- Nam Theun Downstream % of Natural Flow % of Natural Flow (Pre-dam at Ban Thalang) (MCM) stream of Nam Phao (Pre-dam Nam of Nam Phao with Ripar- Without Riparian With Riparian (MCM) Theun plus Nam Phao) (MCM) ian Release (MCM) Release Release Jan 130 32.5 162.5 37.7 20 23.2 Feb 90 22.5 112.5 27.7 20 24.6 Mar 75 18.75 93.75 23.9 20 25.5 Apr 70 17.5 87.5 22.7 20 25.9 May 145 36.25 181.25 41.4 20 22.9 June 601 150.25 751.25 155.4 20 20.7 July 1362 340.5 1702.5 345.7 20 20.3 Aug 2111 527.75 2638.75 532.9 20 20.2 Sept 1539 384.75 1923.75 389.9 20 20.3 Oct 804 201 1005 206.2 20 20.5 Nov 382 95.5 477.5 100.7 20 21.1 Dec 230 57.5 287.5 62.7 20 21.8 Total 7539 1884.75 9423.75 1946.9 20 20.7 Sources: Nam Theun natural flow at Ban Thalang based on data from SMEC, 1996. Nam Phao flows based on catchment ratios. to minimize impacts. The majority of the following sections are Nam Theun/Nam Kading (KBR 2004), the locations of these IFR based on the findings of this KBR's assessment. sites are shown in Figure 3.33. Plates 1 to 4 present typical aquatic The Riparian Release and terrestrial habitats at selected IFR sites. A survey of river profiles for each IFR site was undertaken (VGS In order to help maintain the ecological value of the Nam Theun 2004). Examples of typical rapid and pool crosssections at each IFR Impacts the Project will release a guaranteed minimum riparian release of site are presented in Figure 3.33. Outputs from this topographic 2 m3/s from the Nakai Dam. An additional annual complementary survey were inpued into a hydrological model in order to assess release of 5 million m3 will also be provided for adaptive manage- (i) the reduction in the weed perimeter; and (ii) the ability of fish ment of flows. to negotiate the rapids during periods of low flow. The riparian release is intended to provide a minimum amount of For the fisheries and social aspects, LARReC (2004) undertook water to maintain a basic level of natural processes and ecologi- a consultation-based fisheries survey to use local knowledge to cal value in the aquatic ecosystem. In particular, it is intended to develop an understanding of fishery dynamics and assess the level maintain connectivity between pools to help ensure that a hetero- of socio-economic dependence upon the fisheries resource in the geneity of aquatic habitats remain and habitats are not isolated. communities downstream of the Nakai Dam. Villages that partici- The ability to vary the flow from the Nakai Dam will be the basis pated in the survey are presented in Figure 3.34. The villages were for a strategically focused adaptive management programme. The selected through advice from the Khamkeut DAFO as being places programme will target the maintenance of aquatic productivity in with important fishing activities in the Nam Theun or its tributar- the Nam Theun. ies. Geographical Description Baseline Figure 3.33 presents the entire length of the Nam Theun and Nam Kading from downstream of the Nakai Dam to the confluence with Demographic Baseline and Impact Zones the Mekong.As the impacts of the Project are expected to decrease The study area between the Nakai Dam and the TH Dam site falls downstream and because of the distinct hydrological features and entirely under the authority of Khamkeut District. In total 70 vil- the different types of impacts that might be realized, the Nam lages have been identified as being located within the district. The Theun/Nam Kading have been divided into three main reaches: (i) 70 villages within Khamkeut District were populated in 2004 by the Nam Theun directly downstream of the Nakai Dam to the first approximately 8,556 households and 53,754 people. For the pur- tributary, the Nam Phao; (ii) the Nam Theun downstream of the pose analysis of impacts, the villages in Khamkeut have been sepa- Nam Phao confluence until the Theun-Hinboun (TH) Dam Site; rated of into seven zones based on their use of different waterbod- and the Nam Kading from the TH Dam site until the confluence ies and therefore the likely degree to which they will be impacted. with the Mekong. Where appropriate the discussion is presented The seven village zones consist of (i) Lower Nam Phao, (ii) Upper by these three geographical river reaches. Nam Phao, (iii) Nam Phouang/Nam Phiat, (iv) Nam Kata, (v) Nam Sources of Baseline Data Ngoy, (vi) TH headpond and (vii) Nam Gnouang. The location of these villages, the designated zones and the demographic data for The baseline data comprises of a critical review of exiting reports Khamkeut are presented in Figure 3.34. The population data is as well as additional data gathered specifically for the assessment based on information provided by Khamkeut district staff in 2004. of the riparian release. For the assessment of the riparian release, Amore detailed breakdown of population data by village is avail- biophysical and hydrological characteristics were collected from able in the SDP. representative locations along the Nam Theun/Nam Kading and It should be noted from Figure 3.34 that no permanent villages lie extrapolated to the entire river. Six in-stream flow requirement along the Nam Theun and no land is cultivated from below the (IFR) sites were assigned to be representative of reaches along the Nakai Dam site until the TH headpond, some 40 km downstream. 66 Riparian Release EAMP Main Text Figure 3.33: Zones of the Nam Theun / Nam Kading and sites of surveyed sections Hydrology tivity downstream of the confluence being approximately twice Impacts The baseline hydrology and rainfall data used for the riparian the levels measured above the confluence. This increase in conduc- release assessment is presented in Chapter 3. The effect of riparian tivity reflects the greater population densities that exist in the Nam release on flow rates downstream of the Nam Phao confluence is Phao catchment. presented in Table 3.22 The baseline hydrology for the IFR sites in Terrestrial the dry season and wet season is presented in Table 3.23. Analysis of aerial and helicopter photography shows similar veg- TH Spills and riparian release etation in the geographic sections, from the Nakai Dam to the Nam The average diversion from the TH Dam is 80 m3/s, which repre- Phao confluence and Nam Phao confluence to TH headpond.At all IFR sites, vegetation closest to the river tends to be dominated by sents over 30% of the total incremental flow, or 15% of the total grasses, woody shrubs and fast-growing tree species (KBR 2004). flow. Figure 3.31 shows that there is currently significant reduction Tree species dominated 20 m above wet season water level. Local in dry season discharge downstream of the TH dam resulting from informants indicated that grasses, shrubs and tree species that TH Project operations. were present along the Nam Theun were also common in ditches, Water Quality drains or wetland sites outside of the Nam Theun river valley (KBR 2004). Baseline water quality data for the Nam Theun are presented later in this chapter. In addition, KBR (2004) recorded the value of key Community Use parameters at each of the IFR sites. The input from the Nam Phao Anoverviewofthebaselinecommunityusageofriparianresources seems to influence water quality in the Nam Theun with conduc- of the Nam Theun indicates that this is limited to mainly aquatic Plate 1: Section Site S1, showing both pool and Rapid habitats Plate 2: Section Site S2/3, showing both pool and Rapid habitats Riparian Release 67 EAMP Main Text Table 3.23 Nam Theun/Nam Kading present flow (m3/s) IFR Dry Season Wet Season Sites Absolute Avg Min Mean Avg Max Absolute Absolute Avg Min Mean Avg Max Absolute Min Max Min Max S1 5 25 46 79 887 21 134 420 698 3467 S2 5 26 47 81 911 22 138 431 717 3560 S3 6 33 59 101 1145 27 174 545 906 3640 S4 7 34 61 104 1184 28 180 563 936 3762 S5 5 5 25 78 1897 5 204 869 1550 8878 S6 8 15 42 107 2205 12 253 1019 1805 10260 resources and some terrestrial wildlife. However, these activi- Theun. In addition, persons interviewed were chosen specifically ties occur only in accessible areas (KBR 2004). The river corridor as the "fishers" of the village. Therefore, all estimates of the popu- between Nakai Dam and TH headpond is inaccessible and there- lation mean fish catch from the Nam Theun should be considered fore the riparian resources usage by communities in these areas is as an overestimate of the true mean. minimal (KBR 2004). Table 3.25 illustrates the population data for the villages surveyed, For those riparian resources that are used by communities, most and the estimated numbers of HH engaged in fisheries and aquatic terrestrial flora and fauna species collected by communities were resource collection. An underlying assumption is that 80% of HH present in both in the Nam Theun and sites outside the direct river are engaged in some form of aquatic resource extraction. Variation valley (Table 3.24). These species were mainly collected in forest between villages is significant (between 20 and 100%) however it habitats not close to the river. These species are generally widely indicates that the fisheries are an important element of their liveli- distributed and were recorded as being collected both within the hood strategies. This is reinforced by the importance aached to river valley as well as other areas of the catchment. One exception fish and aquatic animal capture. The fish and aquatic resource pro- was the Big-headed Turtle (Platysternon megacephalum) which spe- duction is ranked second or third in terms of household food secu- cifically inhabits fast-flowing and rocky stream habitats. This habi- rity aer rice and vegetable cultivation, or other forms of natural Impacts tat will be significantly reduced once riparian flows commence. resource exploitation (hunting and gathering of NTFP's). Fisheries Accordingly, results from the survey include two possible geo- graphic delineations; the Nam Theun fisheries and, other tributar- The LARReC (2004) survey included approximately 9% of house- ies and waterbodies (such as rice fields, ponds etc.). In terms of holds(HH)(169HHand1,109ProjectAffectedPersons(PAP))in20 describing current use of fisheries resources and ultimately, ascrib- villages representing a population of 12,600 people and 1,929 HH. ing potential impacts it is important to clearly distinguish areas The 20 villages surveyed formed a sub-sample of the total popula- that willexperienceimpactsofdifferent levels.Adopting the above tion of 70 villages in the entire study area, Khamkeut District, and assumption it is concluded that 6,844 HH are engaged in fisheries were selected on the basis of their likely fishing activity and their and aquatic resource collection with an average of approximately direct use of the mainstream Nam Theun. The villages were also 15% or 227 HH in the Lower Nam Phao zone, 9% or 54 HH in the selected on the basis of their distribution within the catchment, Nam Phouang/Nam Phiat zone and 6% or 91 HH in the Nam Kata and the survey aimed to establish (i) any differentiation between zone engaged in exploiting fish resources directly on the main- communities engaged in fisheries activities within the major trib- stream Nam Theun. utaries, in relation to communities with a higher dependence on A qualitative ranking of waterbodies in terms of fishery impor- resource utilization of the Nam Theun mainstream; and (ii) the tance showed that tributaries of the Nam Theun tended to be of relationship between seasonal distribution and composition of greater importance than the Nam Theun mainstream itself. Table fish stocks within the tributaries and the mainstream of the Nam 3.26 shows that approximately 40% of respondent ranked the Nam Plate 3: Section Site S4, showing both pool and rapid habitats Plate 4: Section Site S5, showing both pool and rapid habitats 68 Riparian Release EAMP Main Text Table 3.24 Summary of community use of riparian resources Phao and Nam Kata as the most important waterbodies. The main- Species Common Name IFR S1 IFR S3 IFR S5 stream Nam Theun ranked only seventh in terms of fishery impor- tance with 5.6% of respondent ranking it as the most important. Flora Insummary,theNamTheunmainstreamisnotanexclusivesource Melientha suavis · · · of fisheries production. Fishing activity on the Nam Theun above Alpinia conchigera · · · the confluence with the Nam Phao is limited to flooding periods Bamboo Shoot · · · only. A range of habitats are exploited, from rapids and waterfalls to ponds and rice fields. Again, no one habitat appeared to be uti- Crateva nurvala · · lised exclusively. Eugenia zeylanica · Effort Calamus spp. · · · Figures 3.35 to 3.37 illustrate respectively, distribution of fishing Rattan Shoot · effort, annual production trend, and mean household production Dracaena angustifolia · · · per month. Colocasia petioles · · The distribution of fishing effort and production correspond to the anticipated trend associated with exploitation of migrating stocks Rhapis subtilis · · between April and July. The production trend peaks more sharply Amomum ovoideum Cardemom · than the fishing effort due to the influx of migrating stocks and a Fauna correspondingly higher yield per unit of effort during this period. The trend between August and December is perhaps a lile sur- Gallus gallus Red Junglefowl · · · prising in that downstream migration in October/November might Bandicota indica Great Bandicoot · · have been expected to yield higher catch rates. Tragulus javanicus Lesser Mousedeer · · Socio-economic benefits Callosciurus erythraeus Pallas Squirrel · Fish Catch: A further analysis comparing catch rates within and Impacts Varanus bengalensis Bengl Monitor · · between villages and locations utilizing all the villages that par- ticipated in the LARReC survey has been undertaken. Asummary Ratufa bicolor Black Giant Squirrel · · of the mean annual catch in each village zone is presented in Table Sus scrofa Wild Pig · 3.27. Based on the LARReC (2004) and Schouten et al (2004) reports Paradoxurus sp. Common Palm Civet · some useful statistics on household catches and production trends emerge.Thereisadistinctspatialvariationinthesizeoffishcatches Hystrix brachyuca E.A. Porcupine · and the use of the Nam Theun mainstream. Villages in the Lower Manis javanica Sunda Pangolin · Nam Phao tend to have the greatest catches with an average of 142 kg/hh/yr or 12 kg/hh/month. Where as the mean annual household Platysternon megacephalum Big-headed Turtle · catches for villages in the Nam Phouang/Nam Phiat and Nam Kata Note: · Indicated by communities as only found in river vally catchments were slightly less, at just under 100 kg/hh/yr. The mean Figure 3.34: Villages surveyed for riparian study Riparian Release 69 EAMP Main Text Table 3.25: Surveyed population and resource utilisation Village Popn HH HH fishing % HH fishing Interviews x HH NT Other NT Other HH PAPS size Nam Phao 556 99 0 79 0 100 7 42 6.00 Oudom 868 152 73 49 60 40 11 74 6.73 Phonelom 383 60 41 7 86 14 7 50 7.14 Phonethong 602 103 58 25 70 30 10 74 7.40 Thong 554 92 0 74 0 100 8 50 6.25 Keng Bid 632 102 61 20 75 25 8 50 6.25 Khammuane 650 105 0 84 0 100 8 42 5.25 Korphay 1250 161 0 129 0 100 7 47 6.71 Lak 10 804 106 0 85 0 100 8 65 8.13 Lak 5 698 101 8 73 10 90 11 73 6.64 Lak 7 761 114 0 91 0 100 10 81 8.10 Phayard (Nadeua) ? ? 100 9 55 6.11 Nong Kok 415 72 51 7 88 12 8 47 5.88 Pha Meuang 795 99 0 79 0 100 8 61 7.63 Phone Sy (Phonvilay) 433 67 0 54 0 100 8 52 6.50 Sopphouan 255 45 0 36 0 100 7 41 5.86 Tha Bac 1012 169 135 0 100 0 8 40 5.00 Thongkair 835 120 0 96 0 100 8 50 6.25 Vangkor 459 70 0 56 0 100 9 54 6.00 Impacts Vangpha 638 92 0 74 0 100 9 61 6.78 Total 12600 1929 427 1116 169 1109 6.56 annual household catch for villages in the Upper Nam Phao was very low at just 16 kg/hh/yr. This may reflect the fact that these villages at located on a main trade route, between Lao PDR and Vietnam, and have other opportunities to generate income. Overall fish catches by communities in the downstream Nam Theun area are significantly lower than the mean monthly catch of 27 kg reported in the Xe Bang Fai area. This probably reflects that those villages in the Nam Theun area are generally poorer, which Table 3.26: Ranked Importance of Waterbodies Water Body % Importance Nam Theun - mainstream 5.6 Nam Theun - TH Headpond 13.0 Figure 3.35: Distribution of fishing effort Ban Oudom Nam Ao 0.6 Nam Phouane 5.7 Pond/Rice field 8.1 Nam Kata 19.9 Nam Phao 21.0 Nam Thin 4.1 Nam Ngoy 10.7 Huay Ping El 1.7 Nam Gnoung 2.0 Nam Phiat 2.3 Reservoir 1.2 Bought 0.5 No response 3.1 Figure 3.36: Annual fisheries production in Ban Oudom 70 Riparian Release EAMP Main Text in fish/aquatic animal collection utilise the catch for commercial purposes and for the 96% of household that utilise fish and aquatic animal production for household food security, 82% of the total catch is consumed within the household (Table 3.28). In the 20 villages surveyed in the present study, 57% of all HH generated income from a proportion of their catches, and 43% of HH utilised their catch entirely for domestic consumption. The distribution of income and consumption among HH is presented in Table 3.28 and the percentage contribution to household consumption is pre- sented in Figure 3.38. Generally, fishing activities were more important for income and household food supply. However, other aquatic products ranked highly as a food supply, with fewer respondents indicating these types of resources offered significant income in lieu of fishing. It Figure 3.37: Mean annual fisheries production Ban Oudom is indicated that most of the aquatic products were collected from tributaries and other areas (such as rice fields, ponds) outside of the Nam Theun. is also indicated in the fact that 85% of fish production is utilized Aquatic Products: A variety of aquatic products are also caught for subsistence purposes. either to supplement fish catches or for sale. Aquatic products In terms of dependency on the mainstream Nam Theun, predict- catches almost exclusively consist of frogs, snails and shrimp. ably the villages in the Lower Nam Phao have the greatest use with Aquatic products tend to be caught by the women and children an annual mean household catch of approximately 64 kg being of the household and can represent a substantial input into the sourced from the Nam Theun mainstream. This represents almost household. 45% of their total catch.Further uptheNamPhaocatchment,inthe In terms of consumption and sale of aquatic products, an aver- Nam Phoang/Nam Phiat and Nam Kata zones the dependency on age of 81% of households participate in collecting and consuming the mainstream Nam Theun is significantly less. Only 10% and 6% Impacts aquatic products. Table 3.28 shows that of those households col- of their annual catch respectively is being sourced from the Nam lecting aquatic products, 21% sell some of their catch but the pro- Theun. Mean annual household fish catches from the Nam Theun portion of aquatic product catch sold (11%) is low compared with in these villages only amount to 9.6 kg and 2.0 kg. The majority of the proportion consumed (89%). Similar to the situation that exists their fish catch is sourced from either the Nam Phao or its tribu- for fish, aquatic products are collected on a subsistence basis. taries. Further up the Nam Phao catchment, villages in the Upper Nam Phao zone do not use the mainstream Nam Theun which is Only villages in the Lower Nam Phao, Nam Phouang/Phiat and probably a result of the distance required to travel and the difficult Nam Kata zones utilize the mainstream Nam Theun for collection terrain. of aquatic products. Catches are extremely low, with the highest mean annual household catch of 0.5 kg being reported for villages Income: The range of income generated through fish and aquatic in the Nam Kata zone (Table 3.29). Collection of aquatic products products varies considerably. The highest incomes are earned in the Nam Theun mainstream by villages from the Lower Nam from fishing in these HH engaged in fishing in the Nam Theun and Phao and Nam Phouang/Phiat is almost negligible. This is prob- Nam Phao, where there are a higher proportion of professional ably due the effort required to reach the Nam Theun therefore only fishermen. In these rivers the average reported household income the higher value fish are sought. Table 3.29 shows that the majority from the 90% recorded as generating income is US$70 and US$71 of aquatic products are sourced from either from the TH Head- respectively. pond or tributaries of the Nam Theun. The lowest contribution of fising to income comes from the Nam Fish Consumption by Vulnerable Groups: LARReC (2004) Ngoy and Nam Kata villages with US$19 and US$22 respectively. requested survey participants to indicate whether vulnerable It is also the case that there is a greater household effort in the col- groups targeted or avoided consumption of certain species of fish. lection of aquatic animals in these locations and these are utilized Thesevulnerablegroupsincludedtheelderly(>60years),pregnant to supplement household consumption. women, breast feeding women and children. The survey found Based on 127 HH reporting some level of income from collection that these vulnerable groups had no preference for eating certain of fish and aquatic products, the average annual HH catch across species of fish, although the majority indicated that breast feeding all villages and river systems is US$41. Only 3% of those engaged women activity avoided eating some species. The fish species that Table 3.27: Mean % of fishers and mean annual fish catch from each waterbody by village zone Village zone Mean Nam Theun - mainstream TH Headpond Nam Kading Nam Ngoy % HH fishing Catch / HH (kg) Yield (kg/yr) Catch / HH (kg) yield (kg/yr) Catch / HH (kg) yield (kg/yr) Catch / HH (kg) yield (kg/yr) Lower Nam Phao 32 63.54 96009 - - - - - - Upper Nam Phao 36 - - - - 0.52 1393 - - Nam Phouang/Nam Phiat 50 9.55 5768 - - - - 0.01 6 Nam Kata 47 2.60 3058 - - - - - - Nam Ngoy 64 - - 37.69 16772 - - 52.37 23305 TH Headpond 48 - - 72.31 39047 - - - - Nam Gnouang - - - - - - Riparian Release 71 EAMP Main Text Table 3.27: (Cont.) Village zone Mean Nam Gnouang Pond and rice field* Nam Phao Total % HH fishing Catch / HH (kg) yield (kg/yr) Catch / HH (kg) yield (kg/yr) Catch / HH (kg) yield (kg/yr) Catch / HH (kg) yield (kg/yr) Lower Nam Phao 32 1.62 2448 79.12 116776 144.28 215227 Upper Nam Phao 36 6.09 16309 9.65 25843 16.26 43545 Nam Phouang/Nam Phiat 50 0.06 36 0.60 362 83.81 50627 94.04 56799 Nam Kata 47 0.08 122 32.14 49142 34.22 52322 Nam Ngoy 64 0.87 387 8.85 3938 99.77 44402 TH Headpond 48 0.55 297 0.01 6 0.26 140 73.14 39490 Nam Gnouang 118.02 147407 7606 118.02 155013 are avoided by breast feeding women are mainly (i) scaled fish of From the current knowledge, it appears that some fish species the Cyprinidae family (Cyclocheilichthys enoplos, Mystacoleucus aff. migrate upstream in the Nam Theun during different periods Atridorsalis, Hemibarbus maculatus, Acheilognathus deignani, Hampala of the year. The hydrological regime of the Nam Theun is one dispar) ; (ii) catfish species of the Clariidae family (Clarias batrachus, of the major determinants of this upstream migration: (i) during Clarias fuscus); or (ii) eel species of the family Mastacembelidae May/June, at the beginning of the rainy season, when discharge (Macrognathus circumcinctus, Macrognathus siamensis, Mastacembe- is increasing, a large number of fish species migrate upstream to lus armatus) and an eel-like species of the Synbranchidae family spawn in tributaries and ephemeral streams; and (ii) in September (Monopterus albus). when discharge is high, many species (such as those belonging to Spawning and Migration: The knowledge of the spawning and the genera Bangana and Tor, and families Bagridae and Pangasii- migratory behaviour of fish species in the Nam Theun is limited. dae) migrate upstream to spawn when water levels recede and An overview of the spawning and migratory behaviour of key concentrations of suspended solids decline (Schouten, 2004). These Nam Theun fish species is presented in Annex K. two major upstream fish migrations and the success of spawning Impacts Table 3.28: Percentage of fish catch and aquatic products consumed and sold, by village zone Village Fish Aquatic Products % of HH that % of HH that % fish % fish sold % of HH that % of HH that % Aq. Prod % Aq. Prod sold catch and sell fish consumed1 catch and sell AP consumed1 consume fish consume AP Lower Nam Phao Phone Sy 100.0 25.0 96.9 3.1 100.0 0.0 93.8 6.3 Upper Nam Phao Lak 5 100.0 63.6 64.5 35.5 72.7 18.2 87.5 12.5 Lak 7 90.0 44.4 77.8 22.2 90.0 30.0 75.5 24.5 Lak 10 87.5 71.4 71.9 28.1 100.0 62.5 67.5 32.5 Nam Phouang/Nam Phiat Khammouane 100.0 25.0 83.8 16.3 62.5 0.0 100.0 0.0 Sop Phouan 100.0 37.5 86.3 13.8 100.0 75.0 65.0 35.0 Nadeua 100.0 33.3 91.1 8.9 88.9 44.4 85.6 14.4 Nam Kata Kor Phay 85.7 33.3 88.3 11.7 71.4 0.0 100.0 0.0 Thong Ket 100.0 37.5 91.3 8.8 100.0 12.5 93.8 6.3 Vang Kor 100.0 44.4 81.1 18.9 88.9 0.0 100.0 0.0 Vang Pha 100.0 25.0 92.5 7.5 100.0 12.5 97.5 2.5 Nam Ngoy Phameuang 100.0 37.5 91.3 8.8 87.5 37.5 82.9 17.1 Nong Song 87.5 42.9 76.7 23.3 87.5 37.5 80.7 19.3 TH Headpond Keng Bid 100.0 75.0 73.8 26.3 50.0 0.0 100.0 0.0 Nong Kor 100.0 62.5 76.3 23.8 62.5 0.0 100.0 0.0 Ta Bac 87.5 85.7 62.9 37.1 37.5 12.5 93.3 6.7 Mean 96.1 46.5 81.6 18.4 81.2 21.4 88.9 11.1 1only respondents that indicated they catch either fish or aquatic products 72 Riparian Release EAMP Main Text Table 3.29: Mean % of fishers and mean annual aquatic products catch from each waterbody by village zone Tributaries (Phao, Nam Theun TH Headpond Nam Kading Nam Gnouang Ngoy, Phouane, Total Village zone - mainstream Mouan, Thin, Kata) Pond and Rice Annual Catch / HH (kg) Annual Catch / HH (kg) Annual Catch / HH (kg) Annual Catch / HH (kg) Annual Catch / HH (kg) Annual Catch / HH (kg) Lower Nam Phao 0.1 40 40.26 Upper Nam Phao 102.5 102.5 Nam Phouang/Nam Phiat 0.03 13.6 60.5 74.13 Nam Kata 0.53 56.3 56.83 Nam Ngoy 1.08 53.5 54.58 TH Headpond 75.7 77.5 153.2 are determined by discharge, water level fluctuations and water many months within individual species. It seems clear that peak quality. Discharges determine the time, duration and frequency of migration occurs somewhat later than the peak spawning period. existence of aquatic habitats that function as spawning grounds. Figure 3.40 presents the distribution of species numbers in the Given the low primary productivity during the wet season, the fish catches over the year. The diversity of species during the down- are using the Nam Theun during this period mainly as a migra- stream migration is significantly lower than for the upstream tion corridor and less so as a feeding, spawning or nursery ground migration, and for this there is no clear explanation at this stage (Schouten, 2004). (KBR 2004). This migratory paern was identified during consultations with During the LARReC (2004) survey, twelve species were identified communities, which suggests that the key period for spawning is as being vulnerable to high low flow conditions. Impacts February to May with peak spawning period for all water bodies occurring in March (Figure 3.39) (KBR, 2004). Asecondary spawn- Non-migratory exotic species of fish, Common Carp (Cyprinus car- ing in some species occurs in October which coincides with the pio) and Tilapia (Oreochromis niloticus), were recorded as common downstream migration period. However, the Pba Soi migration captures (KBR 2004). The presence of these fish is linked to escap- observed in the Xe Bang Fai, when the juveniles of more than ees from fish culture programs in the upper catchment. These spe- 20 species leave the drying floodplains and ephemeral streams cies are edible and may form an important local source of readily accessible protein. to migrate in the Xe Bang Fai, does not occur in the Nam Theun (Schouten, 2004). This is an important part of the fishery for the Xe Bang Fai. Table 3.30: Contribution of fish and aquatic products to HH income There is sufficient difference between individual species and indi- Village Name Household Activity Income Kip/year vidual tributaries to suggest that discrete spawning groups proba- Nam Phao Fishing 2,200,000 bly occur within tributaries and that spawning activity occurs over Oudom Fishing 12,480,000 Phonelom Fishing 6,000,000 Ponethong Fishing 4,750,000 Thong Fishing and aquatic animals 1,700,000 Keng Bid ** Fishing and aquatic animals 2,300,000 Khammuane Fishing and aquatic animals 700,000 Korphay Fishing and aquatic animals 250,000 Lak 10 Fishing and aquatic animals 4,920,000 Lak 5 Fishing and aquatic animals 2,100,000 Lak 7 Fishing and aquatic animals 7,500,000 Nadeua Fishing and aquatic animals 700,000 Nong Kok Fishing and aquatic animals 1,070,000 Pha Meuang Fishing and aquatic animals 280,000 Phonesi Fishing and aquatic animals 120,000 Sopphuan Fishing and aquatic animals 1,090,000 Tha Bac Fishing and aquatic animals 4,350,000 Thongkair Fishing and aquatic animals 1,450,000 Vangkor Fishing and aquatic animals 2,200,000 Vangpha Fishing and aquatic animals 500,000 TOTAL 56,660,000 ** From Ban Keng Bid the enumerators have changed to represent the proportion of Figure 3.38: Proportion of catch utilised for HH subsistance catches allocated to consumption or income Riparian Release 73 EAMP Main Text Table 3.31: Other uses of the Nam Theun (dashed (-): do not use; cross (x): use) Other Use of the Nam Theun Village Transport Domestic Irrigation Livestock Fishing Washing Waste Disposal Lower Nam Phao Phone Sy - - - - - - - Upper Nam Phao Lak 5 - - - - - - - Lak 7 - - - - - - - Lak 10 - - - - - - - Nam Phouane/Nam Phiat Khammouane - - - - - - - Sop Phouan - - - - - - - Nadeua - - - - - - - Nam Kata Kor Phay - - - - - - - Thong Ket - - - - - - - Vang Kor - - - - - - - Vang Pha - - - - - - - Nam Ngoy Phameuang - - - - - - - Nong Song - - - - - - - TH Headpond Impacts Keng Bid x - - x x x x Nong Kor x x x x x x Tabac x x x x x x - Trends in Fisheries: Annex E shows that the current hydrological likely aributed to the change in flow conditions and water qual- condition in the Nam Theun differs significantly on both a sea- ity in the TH headpond and the inability of some downstream fish sonal and annual basis. The seasonal and annual differences in the stocks to pass over the dam during upstream migrations. Villagers hydrological regime provide a dynamic environment for aquatic also suggest that there is a proliferation in the populations of non- life. The distribution and annual productivity of fish populations indigenous fish species that probably originate from aquaculture fluctuate with these fluctuations of meteorological, hydrological or introductions into the TH Headpond. and the subsequent water quality conditions. During a field visit in 2004, impacts on the aquatic environment Naturally occurring floods modify aquatic habitats which can were observed in both the Nam Phao and Nam Kata (pers. comm. result in significant impacts on aquatic life. An extremely high Roel Schouten). The sources of these impacts in the Nam Phao and flood that occurred in both 1996 and 2002 had severe impacts on Nam Kata were road construction and gold mining activities. the Nam Phao and Nam Gnouang fisheries (Schouten, 2004). The cumulative effect of the impacts identified above have prob- If the number of fishers and fishing effort remained constant, the ably caused the decline in the fisheries of the Nam Theun basin annual fish yield would fluctuate with these meteorological and that was identified by communities during consultation. hydrological cycles. However, the human population in the Nam Aquaculture: Aquaculture appears not to be very well developed Theun basin has been increasing and with the subsequent increase in the area. An average of only 8% of households own a fish pond, in the number of fishers and fishing effort, the annual household with almost half of the villages having no fish ponds at all (LAR- catch has been declining. To maintain their fish catches, fishers ReC 2004). Reasons for such a lack of development of aquaculture increase their fishing effort and use more destructive, non-sustain- are likely to be similar to those in the Xe Bang Fai areas, in that able fishing methods; such as explosives and blocking-off tributar- there is currently abundant fish in the rivers and TH headpond, ies. Villagers in Ban Phonelom report hearing explosions at least the lack of infrastructure and well-developed market systems or twice a day and evidence suggests that fishers from Ban Tabac use transportation services, as well as the lack of knowledge about fish explosives when fishing in the Nam Theun above the TH Head- culturing techniques. pond (Schouten, 2004). The combination of increased fish effort and non-sustainable fishing methods will further exacerbate the Other Water Uses decline in annual fish catch which has been identified by commu- Other uses of the mainstream Nam Theun appears to be minimal. nities within the Nam Theun basin. Apart from the fisheries and a small amount of aquatic product In addition to increasing population, in the tributaries between collection, no other direct beneficial uses of the Nam Theun main- the TH dam and the proposed Nakai Dam, evidence suggests that stream were indicated by persons consulted during the LARReC there has already been a decline in fisheries productivity and bio- survey (2004). Table 3.31 shows that only the villages of Ban Keng diversity as a consequence of the TH Project (KBR 2004). This is Bid, Ban Nong Kor and Ban Tabac use the Nam Theun for domes- 74 Riparian Release EAMP Main Text Table 3.32: Comparison of present and future average dry and wet season Table 3.33: Example of Wetted Perimeter Analysis at IFR S1 flows Q Total Depth Vel Chnl Flow Area Wetted IFR Dry Season Wet Season Perimeter Abs Avg Mean Avg Abs Abs Avg Mean Avg Abs (m3/s) (m) (m/s) (m2) (m) Min Min Max Max Min Min Max Max Rapid S1 41% 8% 4% 3% 0.3% 10% 1% 12% 21% 51% 2 0.7 0.33 6.0 7.9 S2 43% 10% 7% 5% 3% 12% 5% 15% 22% 52% 5 1.0 0.42 12.0 11.2 S3 42% 28% 25% 23% 23% 30% 23% 31% 34% 71% 8 1.2 0.39 20.7 21.3 S4 45% 30% 27% 25% 25% 32% 25% 33% 36% 72% 10 1.4 0.41 24.3 22.9 S5 100% 100% 33% 27% 38% 100% 19% 36% 40% 58% 21 1.8 0.5 41.6 28.9 S6 100% 100% 61% 43% 46% 100% 34% 46% 48% 63% 33 2.2 0.59 55.7 30.4 51 2.7 0.69 74.1 32.3 tic water supply, transportation and watering livestock. These vil- 99 3.4 0.74 133.4 51.9 lages are located along the banks of the TH Headpond and there- fore source their water from the headpond and not the Nam Theun 420 5.4 1.23 377.9 57.5 mainstream. 1757 9.5 1.87 1145.0 57.5 Water abstraction from the mainstream Nam Theun for irrigation 3467 12.6 2.29 1822.4 57.5 is negligible (KBR 2004). There is no evidence of any infrastructure associated with abstraction at any of the IFR sites and no evidence Pool on the banks traveling to these sites. Ban Tabac is the only village 2 8.4 0.001 512.9 101.1 indicating the Nam Theun as a source of water for irrigation but 5 9.1 0.01 583.4 103.7 this village is located along the TH Headpond. Impacts 8 9.8 0.01 648.2 105.6 Assets 10 10.0 0.01 666.9 106.2 No permanent assets were identified during surveys along the 21 10.7 0.03 744.1 108.5 banks of the Nam Theun at IFR sites S1 to S5 but some temporary fishing camps were present at sites S2, S4 and S5. 33 11.2 0.04 801.3 110.1 51 11.9 0.06 873.7 112.2 Impacts 99 13.6 0.09 1057.5 117.5 Hydrology 420 17.6 0.28 1527.2 118.0 An assessment of the impacts on hydrology is required in order to 1757 23.4 0.79 2316.7 118.0 assessthe subsequent impactsonthefisheries.Hydrologicregimes 3467 27.7 1.25 2977.7 118.0 play a major role in determining the biotic composition, structure and function of aquatic ecosystems. Table 3.32 compares the present and future flow conditions in terms of percentage of the mean annual runoff (MAR). MAR of the Nam Theun, between Nakai Dam and the Nam Phao conflu- ence, will be reduced to 12.5%. This would increase on average to 30% below the Nam Phao confluence. On average only 50% of the Nam Kading flow will reach the Mekong River. The minimum wet season flows of the first 12 km reach of the Nam Theun will be reduced to about 3% of the existing flows, while the maximum dry season flow will be reduced to 4%. Similarly the absolute maxi- mum flow during the dry season will be reduced to 0.3%. Upon commencement of riparian releases, approximately half of the minimum dry season flow will be recorded between the Nakai dam site and the TH Headpond (IFR sites S1 to S4). There is no expected change in the minimum dry season flow downstream of the TH dam (IFR sites S5 and S6). Reductions in minimum wet season flows range from 10.5 to 3 times lower at the dam site (IFR sites S1) and above the TH Headpond (IFR site S4), respectively. Minimum wet season flows below the TH dam (IFR sites S5 and S6) are not expected to change. Spills Based on the daily time step reservoir simulation, water is spilled approximately once every 2.7 years. The average annual spill vol- ume is 454 MCM with the largest annual flow of 3,428 MCM. A more detailed description of the spills from the Nakai Dam is pre- sented in Annex F. Figure 3.39: Distribution of spawning activity - Nam Theun and tributaries Riparian Release 75 EAMP Main Text Table 3.34: Summary of wetted perimeter analysis for 2m3/s Riparian Release IFR Site Habitat type Present mean dry Present wetted Riparian Release Future mean dry Future wetted Impact on wetted season discharge perimeter season discharge perimeter perimeter m3/s m m3/s m3/s m % S1 Rapid 25 29.4 2 2 7.88 73 Pool 25 108.8 2 2 101.10 7 S2 Rapid 26 43.7 2 3 20.08 54 Pool 26 Data not available S3 Rapid 33 23.3 2 15 10.29 56 Pool 33 28.4 2 15 21.98 23 S4 Rapid 34 27.5 2 17 25.6 6.9 Pool 34 34.9 2 17 12.16 65 Hydraulic Parameters and Wetted Perimeter to provide a more refined estimate of the reduction in the weed The weed perimeter method has been adopted to assess the perimeter and the subsequent impact on the fisheries. impact of the reduced flow on fisheries in the Nam Theun and sur- Summary of the reduction in weed perimeter resulting from the rounding tributaries. This method is a commonly used hydraulic 2m3/s riparian release presented in Table 3.33. rating methodology that is applied worldwide. It uses the rela- At IFR Site S1, for a rapid is habitat, the current mean minimum tionship derived from changes in river weed perimeter at rep- discharge of 25.4 m3/s at the Nakai Dam site during the dry season resentative cross-sections with changes in discharge. Productiv- would create a weed perimeter of 29.4 m. The riparian release of ity in mainstream Lao rivers occurs mainly during the dry season 2m3/s flowing through the same rapid would give a weed perim- when conditions are more favorable. Dry season sunny days, low eter of only 7.9 m, which corresponds to a 21.5 m or 73% decrease water depth and transparency all contribute to the annual primary in the length of river bed that is covered in water. For a pool habi- production. The contribution of wet season production to overall tat, the mean minimum dry season discharge would result in a Impacts annual production in the Nam Theun mainstream is negligible weed perimeter of approximately 108.8m. The riparian release of (Schouten, 2004). The weed perimeter method uses the assump- 2m3/s would create a weed perimeter of 101.1m in the same pool, tion that fish production is related to food production, which in which is an impact of only 6.8%. turn is related to the amount of weed river bed in the dry season. The severity of impact on the weed perimeter generally dimin- Because of this assumption uncertainties are associated with using ishes with distance downstream of the Nakai Dam. For example, the weed perimeter method. The method is based on general the impact on the weed perimeter in rapid habitat of IFR sites principles and is not proven to be relevant for specific fish in a S2, S3 and S4 is 54%, 56% and 6.9% respectively. The impact of particular river. the riparian release on the weed perimeter of the pools is signifi- VGS (2004) measured ten cross sections at 100m intervals at each cantly less than the impact in the rapids. IFR site. These cross sections were inpued in a one-dimensional steady state model, HEC-RAS (KBR 2004). This model has been developed by the US Army Corps of Engineering and simulates backwater profiles through a river reach for a given inflow. The downstream and upstream boundary conditions for the model were the surveyed river water levels and the estimated flows from nearby streamflow gauging stations, respectively. The stream channel roughness or Manning's n values were estimated during the model calibration process. The model was calibrated using the recorded river flows at Nakai Dam downstream gauging station. Initial results are available only for a typical cross section of a rapid and a pool at each of the IFR sites. The weed perimeter analysis for the remaining cross sections at each IFR site will be conducted Table 3.35: Future flood event occurrence in the Nam Theun and Nam Kading IFR Average recurrence interval site 1 year 2 year 5 year 10 year 20 year S1 Present Absent Absent Absent Absent S2 Present Absent Absent Absent Absent S3 Present Absent Absent Absent Absent S4 Present Absent Absent Absent Absent S5 Present Present Absent Absent Absent S6 Present Present Present Absent Absent Figure 3.40: Distribution of fish species in monthly catches 76 Riparian Release EAMP Main Text Table 3.36: River channel hydraulic parameters for the future average mini- changes in terms of reduction in flow area and weed perimeter, mum flows which are important features for the aquatic habitat integrity. IFR Water falls / Rapids Pools Colloidal Sediment Deposition This is the only component of the total sediment load that will pass through the Nakai Dam and hence the colloidal load will increase elocityV elocityV proportionally in the reach between the Nakai Dam and the Nam Discharge Depth Area idthW Depth Area idthW Phao. If clay deposits become consolidated, then high velocities aterW are required to remobilise these. The deposits may influence nutri- Channel Flow opT aterW Channel Flow opT ent dynamics and turbidity in pools S1 10% 39% 66% 15% 27% 79% 3% 69% 95% Sand Deposition S2 11% 51% 43% 25% 46% 91% 3% 87% 95% Critical velocities for the motion of coarse and fine sand are 0.8 m/s S3 30% 54% 89% 34% 44% 76% 46% 65% 79% and 0.3 m/s, respectively. Directly downstream of the Nakai Dam, S4 28% 59% 55% 51% 87% 94% 29% 92% 98% sand deposits will become reduced with time. Sand deposits are breeding habitats for some aquatic species. S5 100% 100% 100% 100% 100% 100% 100% 100% 100% Gravel/cobbles/boulders Deposition S6 100% 100% 100% 100% 100% 100% 100% 100% 100% Thecoarserbedmaterialsaretransportedatmuchhighervelocities than sands. Decreased velocities will lead to increased infilling of Impacts of the riparian release on other hydraulic parameters in interstitial spaces and when the larger elements are not displaced the Nam Theun/Nam Kading are presented in Table 3.36. In the occasionally, then the bed could become solidified. The interstitial reach of the Nam Theun, between the Nakai Dam and the Nam spaces in between coarse bed materials are an important habitat Phao confluence, flow will be significantly reduced, by 90%, and as zone. However, during a spill event sufficient volume will be dis- a consequence of the water depth in the rapids will be reduced by charged into the Nam Theun to generate flow velocities greater 60% and the flow area by 85% while in the pools the water depth than 2 m/s and then mobilise the accumulated material, avoid- Impacts is only reduced by 21%. The flow velocity will be reduced by 97%. ing the solidification of the river bed. During periods when Nakai Flow velocities in the pools are important since they are the key Dam does not spill it may be necessary to release flows to mobilise elements for the survival of aquatic species. Downstream of the these sorts of materials. Below Nam Phao confluence the impact to TH Dam the impact of NT2 Project on the dry season flows are the movement of gravel/cobbles and boulders will be minimal. insignificant, as the average minimum dry season flows will be Water Quality maintained by the TH releases. Based on the hydrological impacts the relationship between these River Morphology key water quality parameters and specific features are described below. The focus of the descriptions is for dry season flows, when For the riparian release scenario the flow velocities in rapids are water quality in rapids and pools will be directly influenced by a greater than 0.3 m/s in all reaches of Nam Theun and Nam Kading, number of biological, physical and chemical factors. These rela- this means that biofilm development may not take place because tionships will determine the suitability and sustainability of some the mobilization of sediments will provide sufficient scouring. waterbodies for fish survival. However, in some pools the flow velocities are below the threshold velocities of 0.3 m/s required to mobilize fine sediment and there Rapids will be a potential for biofilm development during the dry season. The quality of water in rapids during the dry season will relate to Wet season spills with flows greater than 450m3/s should mobilise flow rate and turbulence. Turbulent conditions tend to replenish the biofilms from the pool section. the concentration of oxygen. The available turbulent flow of rapids Reservoir operation modeling indicates that flood flows below will be reduced markedly under riparian release conditions. The Nakai Dam will be severely reduced. Table 3.37 shows the compar- profile of typical rapids directly below the proposed dam will be ison of the maximum floods for present and the future condition. a depth of less than 0.8 m and an available flow area of just over The flood peak between Nakai Dam and the Nam Phao confluence 6 m2. At a velocity of approximately 0.33 m/s, water will continue would be reduced by 50%. In terms of occurrence 1-year Average to flow over the rapids. The general impacts on key water quality in areas of rapids are as follows: with a larger surface to volume Recurrence Interval (ARI) flood will be virtually lost from the sys- ratio the water temperature will be influence more by the ambient tem between Nakai Dam and the TH headpond (Table 3.35). The temperature. Below the Nam Phao confluence, water temperature lossofthisimportantfloodeventwillcausechannelmorphological Table 3.38: Comparison of present and future MARs (1986-2003) Table 3.37: Comparison of present and future flood peaks IFR Present MAR Future MAR Future MAR as % of IFR Flood peaks (m3/s) (m3x106) (m3x106) Present MAR Site Present Future Change Mean Median Mean Median Mean Median S1 3400 1757 52% S1 7395 5411 842 63 11% 1% S2 3622 1804 50% S2 7594 5556 1039 209 14% 4% S3 4519 2251 50% S3 9527 7497 2867 1705 30% 23% S4 4768 2375 50% S4 9846 7749 3185 1957 32% 25% S5 8876 5116 58% S5 14088 10078 5083 3077 36% 31% S6 10870 6571 60% S6 16737 12096 7732 5095 46% 42% Riparian Release 77 EAMP Main Text will be more influenced by tributaries and may increase due to Below the TH dam site, contributions from the Nam Phao, Nam the reduced depth of rapids; (ii) Conductivity measures below Gnouang and Nam Mouan will influence the distribution of vege- the Nam Phao may be expected to rise, as the Nam Theun will tation and few changes in the species composition and distribution no longer provide a level of dilution; (iii) pH will remain similar of plant communities is likely to result from riparian releases. above the confluence, but may be influenced by inputs from the Nam Phao in lower reaches; (iv) dissolved oxygen will remain Wildlife high in areas of turbulent water movement. Riparian flows should maintain existing terrestrial wildlife cor- ridors and habitats in the Nam Theun valley. Current sources of Pools drinking water, shelter, breeding sites, foraging and connectivity In the area immediately downstream of the Nakai Dam, the flow above the current high water level are not likely to be compro- area of pools will not reduce significantly, but flow velocity will mised with the reduced flow rate. reduce to 3%. Based on this reduced flow the general water qual- Riparianflowsshouldnotimpactonthequalityofhabitatavailable ity parameters in pools will be as follows: (i) water temperature for most of the terrestrial species recorded in the area. Expansion will be more influenced by ambient temperatures; (ii) periodic of vegetation onto exposed river banks may provide additional flooding events will reduce pool temperatures; (iii) conductivity in habitat resources for some wildlife groups. Species that currently pools below the Nam Phao confluence will be directly influenced exploit resources within forest will not be significantly impacted. by inputs from tributaries and higher than current values; (iv) pH Species that utilise arboreal, cryptic or ground-dwelling habitats in pools will fluctuate according to biological conditions; and (v) are unlikely to be negatively impacted as their existing habitat is dissolved oxygen pools below the Nam Phao confluence could be above current high water level. expected to remain higher than for pools above the confluence. The distribution of amphibians and other semi-aquatic species that Plant and animal material deposited in pools will likely remain for rely upon fast-flowing water may be impacted between the Nakai longer periods under reduced flow conditions, so bacterial decom- dam before the Nam Phao confluence. The reduced flow area and position of any organic material will tend to deplete dissolved oxy- velocity will likely influence the availability of breeding habitats gen. With decreased availability of dissolved oxygen, the composi- and feeding resources for species reliant on fast flowing waters. tion of biological resources in the pools will vary considerably and The presence of the endangered Big-headed Turtle species (Platys- may not be conducive to supporting larger macroinvertebrate or ternon megacephalum) recorded downstream of the TH dam is vertebrate species. important. This species is known to inhabit fast-flowing areas and Production of biofilms in pools located above the Nam Phao con- is listed under IUCN and CITES conventions. The presence and Impacts fluence will increase as the velocity decreases. In slow-flowing extent of this species in the Nam Theun will be further investigated conditions, phytoplankton densities may increase, causing fluc- as part of the monitoring programs outlined below. tuation in water quality that reflects the diurnal paerns in pho- tosynthesis. Community use of vegetation and wildlife With the exception of the big headed turtle, all species identified Supersaturation by communities as being hunted for consumption can be found Spill waters exiting Nakai Dam may produce supersaturated con- both within and outside the Nam Theun river valley. Given the ditions during periods of high flow. However, the scale of impacts known habits of species considered important by the local commu- from these conditions should not be detrimental to downstream nities, the ecological requirements of most of these species should fish populations and will be rapidly assimilated into downstream continue to be met by under the riparian release conditions. As a waters. Spills will be received into a relatively shallow spill-pool, result, no significant social implications on riparian resource use reducing the likelihood of creating concentrations of supersatu- should result from the riparian release. rated waters lethal to fish species. Fisheries Terrestrial Thebroadimplicationsisthatreducedflowsarisingfromtheripar- Vegetation ian release will modify the hydraulic and physico-chemical condi- tions in the mainstream Nam Theun, especially in reaches between The exposure of river banks under the reduced flow conditions the Nakai Dam and the Nam Phao confluence. The subsequent willcauseencroachmentofterrestrialvegetationontosuitablesub- reduction in the flow will reduce the carrying capacity of the river, strates. The exposed river banks will be suitable for colonization both in terms of fish diversity and abundance. An important ques- by fast growing species such as gasses. However, the suitability tion will be if the aquatic habitats in the mainstream Nam Theun of bank substrates for vegetation colonisation is variable. Analysis will still provide a dry season refuge for those species that migrate of photographs between the Nakai Dam and the Nam Phao conflu- upstream in May/June and in September into the tributaries of the ence indicates only limited areas where significant transgression of Nam Phao, Nam Kata, etc. The outputs from the weed perimeter vegetation towards the limits of dry season flow could be expected analysis will be used later in this section to determine the impact (KBR 2004). This section of the Nam Theun includes large areas on the fisheries. This will have corresponding impacts on current of boulders and it is unlikely that these substrates would contain fishing practices and levels of fish production, and subsequently sufficient deposits of topsoil to support significant vegetation on socio-economic conditions in the Nam Theun and tributaries. growth. The limited available information on the biological requirements Downstream of the Nam Phao confluence to the TH headpond, and migratory behavior of fish species, together with the numer- the frequency of boulder and rock adjacent to the river is less. ous seasonal fluctuations in variables that control fish productiv- Reduction in river height in these areas may result in significant ity, make it difficult to quantify the precise impact on the fisheries. transgression of fast-growing species such as grasses and woody Biodiversity and Abundance shrubs. The section of Nam Theun from the TH dam to the NT2 Dam will Stripping of vegetation between the dam site and TH headpond is be totally isolated from the Nam Theun upstream of the Nakai likely to occur only intermiently with the periodic spill events. dam and potentially isolated from the Nam Kading downstream 78 Riparian Release EAMP Main Text of the TH dam. There will be no possibility of migration of fish Table 3.39: Fish species potentially vulnerable to low flows (KBR, 2004) species to the Nakai Plateau. Therefore a loss in the number of spe- cies may be expected due to this fragmentation. Ongoing impacts Waterbody Species Name identified earlier in the section that are independent of the Project, Nam Theun · Hemibagrus wyckioides such as the ongoing destruction of the fisheries and flood events in · Bagarius yarrelli · Poropuntius sp. the Nam Phao, will aggravate any impacts by the Project. · Hemibagrus Wyckii The upstream migration of fish species in the Nam Theun will be · Puntioplites wandersi impacted by the reduction in discharge by the Project. Reduced · Acheilognathus barbatulus · Crossocheilus reticulatus flow during migration periods will place pressure on those spe- · Garra imberbis cies (Table 3.39) that demonstrate existing vulnerability to low · Hypsibarbus wetmorel flow conditions. However, discharges downstream of the Nam · Cyprinus carpio Phao confluence will still be approximately 20% of the current dis- charge. Nam Phao · Puntionlites falcifar · Cychocheilichthys armatus It may be that the Nam Theun mainstream will still function as a dry season refuge for those species that migrate upstream into the Nam Ngoy · None indicated tributaries during the wet season. Fisheries in the tributaries may Nam Kata · None indicated therefore experience lile impact other than through reduced pro- ductivity in the Nam Theun mainstream and isolation between the Other Tribs. · None indicated TH dam and Nakai dam. These fragmented populations will be more vulnerable to natural extremities such as flooding. any increases in productivity per unit area of periphyton, macro- Modified water quality may be expected to modify spawning suc- phytes and invertebrates that is promoted by an increase in water cess in those species that spawn in the mainstream. Similarly the reduced depth and morphological changes will reduce access to transparency and a reduction water depth. Fish that adapt to the spawning habitat among those species utilizing riparian vegeta- low flow conditions may proliferate. tion. The area of spawning habitat will also be reduced. Although Downstream of the TH Dam site, it is assumed that stream biota forthosefishusingvegetationasaspawningsubstrate,macrophyte have adapted to a certain flow regime and can survive the current Impacts stands that are initially stranded aer dam closure should develop periods of low flow. Therefore in terms of biota, the status quo is further down the bank to retain some heterogeneity of habitat. It is likely to be retained if the minimum flow does not fall below the assumed spawning and recruitment in the tributaries will remain current average low flow. Because the mean minimum low flow largely unchanged, albeit with a reduced spawning stock. is maintained below the TH dam no impacts significant on biota The reduced pool depth and water quality conditions may influ- is anticipated. ence the availability of dry season refuge habitats, and correspond- Socio - Economic Analysis ingly the carrying capacity of these areas will be impacted. The reduced water level will expose many of these refuges, limiting the TheenvironmentalimpactsoftheProjectproposedriparianrelease complexity of habitat features above the Nam Phao. of 2m3/s on the Nam Theun will have several negative impacts on It is likely that the abundance of exotic species (Common carp and the communities located downstream of the Nakai Dam. These Tilapia) will increase following the closure of the Nakai dam due impacts can be summarized as loss of production of (i) fisheries; to their capacity to adapt to a much wider range of conditions. and (ii) aquatic products. This may put further pressure on the specialized indigenous fish In order to evaluate the socio-economic impacts of the Project the species. villages have been divided into zones based on the level of use on It is clear that following the construction of the TH dam the the Nam Theun mainstream and therefore severity of impact on impounded stock have continued to migrate, spawn and sustain the communities. population in a significantly reduced environment. It is therefore Fisheries expected that tributaries will continue to function although the overall stock will be reduced. The extent to which this impound- The Nam Theun mainstream is generally not an exclusive source mentwillaffectthegenepoolisunknown.However,itislikelythat of fisheries production, indeed the Nam Theun ranked only sev- susceptibility to disease will increase. Long distance migrant fish enth in terms of importance. Therefore the severity of the impact species that refuge in the Nam Theun during the dry season will be on the Nam Theun mainstream will be buffered by the communi- impacted by the Project. Those resident fish species of the tributar- ty's preferential use of tributaries and other water bodies. ies that only undertake short distance migration will remain unaf- Impact on Fisheries by River fected and may benefit from the reduced competition for resources The following section outlines `ballpark" estimates for the maxi- by a decline in long distant migrants. Adetailed discussion on the mum potential impact of the Project on annual fish yields and potential impacts on important migratory fish species in the Nam Theun is presented in Annex K. the value of any losses. The current fish catch data is sourced from the consultation based fisheries surveys of LARReC (2004) Impacts on fish abundance will be most severe in the Nam Theun and Schouten et al. (2004). A market value of USD 0.8 per kg was reach between the Nakai Dam and the confluence with the Nam adoptedtocalculatethevalueofthecatchinmonetaryterms. Table Phao. Downstream of the Nam Phao confluence catchment inputs, 3.40 provide, a summary of the estimated impact by the Project by including the Nam Phao itself, that are unaffected by the Nakai village zone and the subsequent value of the losses. These estima- dam will help buffer the severity of any impacts. tions are based on mean catch data recorded by LARReC (2004) Overall fish productivity will be reduced due to the significant and the estimated severity of impact identified below. The predic- reduction in the carrying capacity of the reduced discharge. How- tion of the impacts and the subsequent estimation of losses in fish ever, the change in hydrology is not expected to result in the par- yield can only be indicative at this stage. Only aer dam closure tial collapse of the food chain. Reductions in populations of species when the impacts occur can the monitoring obtain a more accurate thatareabletotoleratethemodifiedhydrologymaybebufferedby value. Riparian Release 79 EAMP Main Text Nam Theun Mainstream: The productivity of the fish species the Nam Phao and its tributaries catch are long distance migratory taking dry season refuge in the mainstream Nam Theun will be fish, and the impact on those migratory species in the Nam Theun impacted by the reduction in dry season flow. Assuming that pro- mainstream is 60%, the overall impact on fish catches could be up ductivity is related to the amount of river bed that is inundated, to 35%. The scale of impact on the Nam Phao is less than that on productivity of the Nam Theun fishery may decrease by the same the mainstream Nam Theun but because of the greater use of the order of magnitude that the weed perimeter is reduced. Based Nam Phao the value of the loss in higher.A35% impact in the Nam on the weed perimeter analysis, the reduction in amount of wet- Phao fisheries equates to a decline in fish catch of 83,908 kg/yr at a ted river bed in the mainstream Nam Theun, and therefore the value of USD 67,126. The decline in fish catch will be experienced reduction in the area for primary and secondary production, at most by villages in the Lower Nam Phao zone, as well as the Nam sites IFR S1 to S3 is 73%, 54% and 56% respectively. This gives a Kata, Nam Phouang/Phiat and Upper Nam Phao zones. mean impact of approximately 60% of the mainstream Nam Theun The impacts on fish catch in the Nam Phao could be potentially between the Nakai Dam and the TH Headpond. A 60% impact in the Nam Theun mainstream fisheries equates to a decline in fish buffered by migratory individuals in the Nam Theun being catch of 62,901 kg/yr or USD 50,321. The decline in fish catch will aracted into the Nam Phao during wet season by the relatively be experienced most by villages in the Lower Nam Phao zone. larger discharge in the Nam Phao compared to that in the Nam Theun above the Nam Phao confluence. TH Headpond: Aer inundation by the TH Project the number of fish species in the TH headpond declined but the annual fish yields Nam Gnouang: Fish catches in the Nam Gnouang are already increased,indicatinganincreaseinfishproductivity.Theprolifera- impacted by the presence of the TH dam which impedes the tion of one species (Cyprinus carpio) more than compensated for the upstream migration of fish from the Nam Kading and Mekong. loss of productivity in the other fish species. The NT2 Project will Although there is anecdotal evidence to suggest that some fish have relatively lile effect on the hydrology of this already lacus- species can still navigate across the TH dam during the peak of trine environment and therefore no impact on the productivity of the wet season, the TH Project has still resulted in a 40% decline in those fish already adapted to the new conditions is perceived. householdfishcatchinvillagesalongtheNamGnouang(Schouten et al. 2004). This decline is probably aributed to the inability of Project reductions in the inflow into the TH Headpond will influ- the majority of long distance migratory fish species to pass the TH ence the water quality in the TH-Headpond. During the dry sea- dam or the timing of their migration not being compatible with TH son, low dissolved oxygen conditions currently develop at depths spills. Therefore majority of the fish catches in the Nam Gnouang of more than 10 meters. Reduced inflows into the TH Headpond probably consist of non-migratory or short distance migratory fish will most likely extend the period over which these low dissolved species. The NT2 Project will have no impact on this proportion of Impacts oxygen conditions. This may lead to a further reduction in the the fish catch. number of species inhabiting the TH Headpond. Whilst the major- ity of fish species are affected by dissolved oxygen less than 4 mg/l, However, because the NT2 Project will cause an average reduction Cyprinus carpio that has proliferated in the TH Headpond can toler- in the numbers of days that the TH dam will spill, from 245 days to ate dissolved oxygen as low as 2 mg/l so will remain largely unaf- 190 days per year, and reduce the mean monthly discharge in Sep- fected by the change in water quality and, in fact, may proliferate tember from 1,323 m3/s to 806 m3/s, the NT2 Project will have an because of the reduction in competition (Schouten, 2004). additional impact on any long distance migratory fish species that currently manage to pass upstream of the TH dam. This reduction Nam Phao and Tributaries: Non migratory and short distance in spills will particularly affect the fish population of the family migrant fish species that are residents of Nam Phao and its tribu- Pangasiidae which may not be able to complete its full life cycle taries will not be affected by the Project. Only those species that if isolated above the TH dam. Other fish species, such as those refuge in the mainstream Nam Theun during the dry season then belonging to the genera Bangana and Tor and family Bagridae, are move into the Nam Phao in wet season will be impacted. Based highly likely to be able to complete their full life cycle when con- on the assumption that approximately 60% of the fish species in fined to locations upstream of the TH dam (Schouten, 2004). The Table 3.40: Estimated value of fisheries loss for the riparian release of 2 m3/s Village Zone Source of Fish Catch Nam Theun TH Headpond Nam Ngoy Nam Gnouang Pond/rice field Nam Phao and Total - mainstream tributaries Decline Value of Decline Value of Decline Value of Decline Value of Decline Value of Decline Value of Decline Value of in Yield Loss in Yield Loss in Yield Loss in Yield Loss in Yield Loss in Yield Loss in Yield Loss kg/yr USD kg/yr USD kg/yr USD kg/yr USD kg/yr USD kg/yr USD kg/yr USD Lower Nam 57,605 46,084 0 0 0 0 0 0 857 685 40,869 32,695 99,332 79,465 Phao Upper Nam 0 0 0 0 0 0 0 0 5,708 4,567 9,045 7,236 14,753 11,802 Phao Nam Phouang 3,461 2,769 0 0 1 0 4 3 127 101 17,719 14,176 21,311 17,050 / Nam Phiat Nam Kata 1,835 1,468 0 0 0 0 0 0 43 34 17,200 13,760 19,077 15,262 Nam Ngoy 0 0 0 0 2,330 1,864 39 31 788 630 0 0 3,157 2,525 TH Headpond 0 0 0 0 0 0 30 24 0 0 49 39 79 63 Nam 0 0 0 0 0 0 14,741 11,793 1,521 1,217 0 0 16,262 13,010 Gnouang Total 173,971 139,177 NPV 1,172,113 80 Riparian Release EAMP Main Text population of these species will become fragmented which may The impact on productivity may be buffered by any increases in eventually lead, over generations, to local extinction. primary production in those areas still submerged. Primary pro- If it is assumed that 30% of the catch in the Nam Gnouang consists duction per unit area may increase due to a decrease in water of long distant migrant species and the reduction in the number of velocity, a decrease in water depth and an increase in water trans- spilling days is a conservative 30%, an estimated maximum poten- parency. These factors will favor photosynthesis and result in a tial impact of 10%, a 30% impact on 30% of the catch, has been proliferation of periphyton and macrophytes. This may buffer the aributed to the overall catch in the Nam Gnouang. A10% impact negative impact on overall productivity of aquatic products. in the Nam Gnouang fisheries equates to a decline in fish catch of Aquatic product collection in the Nam Theun mainstream is negli- 14,813 kg/yr at a value of USD 11,850. The decline in fish catch will gible.Onlyafewvillagesindicateuseofthemainstreamasasource be experienced mainly by villages in the Nam Gnouang zone. of aquatic products. Villagers tend to collect aquatic products from Nam Ngoy: Similarly to the Nam Gnouang, fish catches in the local tributaries or ponds. Given that community use is so low the Nam Ngoy are already impacted by the physical presence of the reduced populations of aquatic products may still be sufficient to TH dam, as well as, the TH Headpond. Whether the fish species provide a sustainable resource. Table 3.41 provides a summary of that manage to negotiate the TH dam are aracted solely to the the estimated impact by the Project on aquatic product catch in the Nam Gnouang or continue to migrate upstream through the lacus- mainstream Nam Theun. The aquatic product catch data is based trine TH Headpond and into the Nam Ngoy remains to be studied. on the consultation based fisheries surveys of LARReC (2004) and Either way, the majority of fish catches in the Nam Ngoy are prob- a market value of USD 0.3 per kg was assumed for calculating the ably made up of short distance migrants from the TH headpond or value of the catch. A 60% impact in the Nam Theun equates to a non-migratory resident fish species. The NT2 Project will have no decline in aquatic product collection of only 588 kg/yr at a value impact on this portion of the catch. Therefore an estimated maxi- of USD 407. In net present value terms this equates to only USD mum potential impact of 10% has been aributed to the overall 4,000. catch.A10% impact in the Nam Ngoy fisheries equates to a decline Note that no aquatic products catch data was available for the in fish catch of 2,331 kg/yr at a value of USD 1,865. The decline in villages located long the Nam Gnouang. It is assumed that their fish catch will only be experienced by villages in the Nam Ngoy aquatic products are obtained either from the Nam Gnouang or zone. TH Headpond and therefore unaffected by the Project Impacts Pond and Rice Paddies: No villages source their domestic water from the mainstream Nam Theun. The Project will therefore have Others Uses no impact on the limited aquaculture already established in the Because communities indicated no "other uses" of the mainstream area. Nam Theun above the TH Headpond it is not expected to be any Given the steep terrain directly adjacent to the Nam Theun main- impacts to (i) riverside assets including riverbank gardens; (ii) stream, between the Nakai Dam and Nam Phao confluence, the domestic water use; (iii) irrigation systems; and (iv) navigation. Project will have no hydraulic related impacts on naturally stock Thereforethesocio-economicanalysisislimitedassessingthevalue ponds or rice field fish populations in this reach.There no evidence of the loss to the fishery and aquatic products, no value of loss has of ponds or rice paddies along this stretch of river. been aributed to "other uses" of the Nam Theun mainstream. The Project will have an impact on seasonal, naturally stocked Value of the Riverine Ecosystem ponds and rice fields adjacent to the Nam Theun tributaries that At commencement of the riparian releases, the project will result rely on long distance migrating fish species to enter these areas for in an impact on the aquatic ecosystems in the reach of the Nam feeding, spawning and nursery habitats. Given that the species in Theun between the Nakai Dam and the TH Hinboun headpond. the mainstream and tributaries will move into these flooded areas, This ecosystem includes the habitats of at least one endangered the assemblages in the naturally stocked ponds and rice fields may species, the big-headed turtle. Given this lack of quantified data in be similar. The severity of impact should reflect the impact on the this area, the most plausible approach for assessing the magnitude tributaries adjacent to the ponds. The estimated impact on the of the impact on these aquatic habitats is to estimate values for the ponds and rice field fisheries equates to a decline in fish catch of entire ecosystems, rather than the specific species, by imputing a 9,043 kg/yr at a value of USD 7,235. value in relation to terrestrial habitats. Unfortunately the LARReC (2004) survey did not distinguish Accordingly, it is assumed that one kilometer of river is equal, between aquaculture ponds and seasonal, naturally stocked fish in conservation terms, to 50 hectares of terrestrial habitat (Louis ponds/rice fields therefore allocating a precise value to the loss is Berger, 1997). The length of the river affected, between Nakai Dam difficult. andTHheadpond,is40km.Usingthesamevaluesasestimatedon Summary of Loss of Fisheries: Over the entire study area above the Economic Impact Study of Nam Theun 2 Project (Louis Berger, the TH dam the estimated impact will result in a decline in fish 1997) of USD 75-125 per terrestrial hectare per year the Project catch of 173,971 kg/yr which equates to USD 139,177. In terms of would result in an estimated USD 150,000 ­ 250,000 per year of the net present value the loss is approximately USD 1.17 million over loss for biodiversity, pharmaceutical and eco-tourism potential of the 25 years of operation of the Project. these aquatic ecosystems. This is equivalent to a net present value Aquatic Products in 2004 of USD 1.26 to 2.11 million. The Project will not have any impact on the aquatic products pop- Vulnerable Groups ulation in the TH headpond or in the tributaries of the Nam Theun. If certain species of fish were exclusively consumed by a particu- There will, however, be an impact on those populations inhabiting lar vulnerable group, such as pregnant mothers or children, then the Nam Theun mainstream between the Nakai Dam and the TH any impacts on those species would result in a disproportionately Headpond. The riparian release will cause a reduction in the wet- largerimpactonthosevulnerablegroups.Thiswouldbeimportant ted perimeter and therefore a decline in the area for primary and if the fish species were consumed for special dietary requirements, secondary production. Based on the weed perimeter analysis an such as nutrients during child development. The LARReC (2004) impact on productivity of 60% has been allocated. survey found that vulnerable groups had no preferences for cer- Riparian Release 81 EAMP Main Text tain types of fish therefore no disproportionate impact is expected The point of inflection on the weed perimeter curve represents on those vulnerable groups. the maximum habitat for the minimum flow. A riparian release of Other non-Project Impacts 8 m3/s would be sufficient to meet the minimum weed perimeter for sites above the Nam Phao confluence. These additional ripar- In addition to those impacts caused by the Project several other ian release discharges are still less then the current mean dry sea- factors will influence the productivity of the fisheries, these fac- son flow so will themselves have an impact. Table 3.42 presents the tors have been identified by villagers as resulting in an ongoing weed perimeter analysis and estimated magnitude of impact for decline in fish catch that is independent of any Project activities. the riparian release regimes of 5 m3/s and 8 m3/s. These non-Project impacts include (i) proliferation of non-indig- enous fish species that are probably escapees from aquaculture; The impact on the weed perimeter, and the perceived impact on (ii) population increase resulting in increased fishing pressure; and fish productivity, decreases with increasing discharge. For exam- (iii) increased use of more efficient fishing methods. ple, a riparian release of 5m3/s and 8 m3/s will have impacts of 62% and 27% respectively at IFR Site S1 which compares an impact of Impacts of Other Planned Hydroelectric Projects 73% resulting from the riparian release of 2m3/s. Limiting the over- The Theun-Hinboun Extension Project is a planned storage reser- all reduction in the weed perimeter will mean larger areas for voir on the Nam Gnouang that will increase the dry season flow productivity of the fisheries will remain. A summary of the esti- into the TH Headpond and provide more water for electricity gen- mated potential impact on fish productivity is shown in Table 3.43. eration by the TH Project. When Theun-Hinboun Extension is con- Similar assumptions as those for the 2m3/s were used to generate structed its operations will significantly impact both the discharge these estimates. in the Nam Gnouang and inflows into the TH Headpond. It is Theimprovementsinfisheriesproductivitybyincreasingtheripar- expected that the TH Extension will commence operations around ian release are limited to only the fisheries in the mainstream Nam the same time as, or possibly before, the NT2 Project. No planned Theun and Nam Phao. Productivity for long distance migratory downstream discharges for the TH Extension are available thus fish species that refuge in the Nam Theun will improve as weed the cumulative impacts on the Nam Theun/Nam Kading basin can perimeter is increased. No significant improvements in the impact not be estimated. Fish species of the Nam Gnouang, in particular on the Nam Gnouang and Nam Ngoy fisheries are expected by Scaphognathops theunensis, will be significantly impacted by the TH increasingtheriparianrelease.Thesefisheriesareimpactedmainly Extension. by a reduction in the volume and number of days the TH dam is spilling. Small volumetric increases in the riparian release will Trade-off cause lile improvement relative to the total volume of the spill. Impacts The potential socio-economic cost of the riparian release of 2 m3/s Table 3.44 presents the value of the losses in the fishery and aquatic has been estimated as USD 1.17 million for the fisheries/aquatic products for the riparian release of 5 and 8 m3/s. The estimated products and USD 1.26 to 2.11 million for the aquatic ecosystem value of the losses in the fisheries for the riparian releases of 5 and in net present value terms. The overall cost of the 2 m3/s riparian 8 m3/s, net presents value terms of USD 1.0 and USD 0.69 million release is in the range of USD 2.43-3.28 million. Of these costs, the respectively, are less than the value of the loss with the 2m3/s ripar- potential impacts to the aquatic ecosystem could be greater than ian release. The estimated value of the losses in the aquatic prod- the impacts to local communities in comparison to overall costs. ucts for the same riparian release scenarios is approximately NPV To determine the most appropriate riparian release a tradeoff USD 3,300 and 2,000. analysis to estimate the potential financial costs and the ecological/ At this stage it is too difficult to allocate the improvement to the social benefits of different riparian flow regimes was conducted. aquatic ecosystem that is gained by increasing the riparian release. Based on the weed perimeter analysis, the point of inflection of Therefore for the trade-off the value of the loss remains constant the weed perimeter-discharge curve could be either 5 or 8 m3/s. for all scenarios. Table 3.41: Estimated value of aquatic products loss for the riparian release of 2 m3/s Source of Aquatic Products Nam Theun TH Headpond Nam Ngoy Nam Gnouang Pond/rice field Nam Phao and Total - mainstream tributaries Village Zone Decline Value Decline Value Decline Value Decline Value Decline Value Decline Value Decline Value in Yield of Loss in Yield of Loss in Yield of Loss in Yield of Loss in Yield of Loss in Yield of Loss in Yield of Loss kg/yr USD kg/yr USD kg/yr USD kg/yr USD kg/yr USD kg/yr USD kg/yr USD Lower Nam Phao 91 73 0 0 0 0 0 0 0 0 0 0 91 73 Upper Nam Phao 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Nam Phouang / Nam Phiat 11 9 0 0 0 0 0 0 0 0 0 0 11 9 Nam Kata 486 389 0 0 0 0 0 0 0 0 0 0 486 389 Nam Ngoy 0 0 0 0 0 0 0 0 0 0 0 0 0 0 TH Headpond 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Nam Gnouang 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Total 588 470 NPV 3,960 82 Riparian Release EAMP Main Text Increasing the riparian release to benefit the fisheries downstream Reservoir. The multilevel intake will source water for the down- of the Nakai Dam will have a cost in terms of loss of revenue from stream Nam Theun from only the good quality surface (epilim- power production. The loss of revenue for the 5 m3/s and 8 m3s nion) water and not the potentially oxygen poor boom (hypolim- riparian releases is USD 45 and 72 million respectively. Indeed nion) water. for any significant reduction in the impact in the fisheries a 8 m3/s Cone Valve: At the Nakai Dam, the riparian release will be dis- riparian release would be required. The financial cost of a 8 m3s charged through an aerating structure, a cone valve, into the still- riparian release is USD 72 million but the improvement in the fish- ing basin. It is anticipated that the cone valve can increase dis- eries only equates to approximately USD 0.5 million. The loss of revenue, a proportion of which will go directly into development solved oxygen levels in the discharged water by up to 5 mg/l. programmesinthecountry,byfarexceedstheecologicalandsocial Detaileddrawingsofthestructuresassociatedwithriparianrelease gains by providing the additional riparian release. are presented in Annex D. Mitigation Mitigation against Sedimentation To mitigate against any impacts associated with construction site Mitigation Against Poor Water Quality erosion, the HC will prepare and implement an erosion and sedi- Like the Xe Bang Fai, the overall objectives of mitigation for water mentation plan for the various engineering works associated with quality are to (i) maintain the current beneficial uses of water in the the Nakai Dam. Mitigation measures will include drainage works, Nam Theun; and (ii) avoid or minimize any water quality impacts sediment traps and other structures designed to treat water to an on the fisheries. It should be noted that, apart from fisheries, ben- acceptablequalitybeforedischargingintotheNamTheun.TheHC eficial uses (irrigation, domestic water supply, etc.) has been indi- will minimize working during the wet season to further minimize cated as minimal along the Nam Theun mainstream (LARReC any erosion. Details of the requirement of this plan is presented in 2004) with no permanent selements existing between the Nakai Annex L. Dam Site and the TH Headpond. Mitigation Against Injury From Flash Floods Biomass Reduction The Nakai Dam will be fied with a siren that will be operated In order to reduce the amount of biomass decomposition and before any opening of the dam gates to warn people in the Nam Impacts therefore the extent of anoxic conditions that may develop in the Theun below of the impending increase in water depth and veloc- reservoir in the initial years aer inundation of the reservoir, the ity. Project will encourage the removal of biomass through salvage logging and promotion of firewood collection and/or charcoal pro- Morphology duction by villagers. A number of physical interventions to channel morphology may Engineering Works be suitable for improving the weed area of rapids and the flow in deep pools. These interventions include (i) seing channel dimen- Multilevel Intake: The intake at the Nakai Dam site will help sions to simulate natural conditions, albeit on a smaller scale; (ii) reduce the downstream impacts of any anoxic conditions that may increasing the complexity of pool shorelines to provide habitat develop in the Nakai Reservoir. The design of the intake will be protection zones for fry and small fish; (iii) reinstating meanders such that water can be sourced from a specific depth in the Nakai to trap transported sediments and avoid scouring of biofilm; (iv) Table 3.42: Summary of wetted perimeter analysis for the trade-off Present mean dry Present wetted Riparian Release Future mean dry Future wetted Impact on wetted IFR Site Habitat Type season discharge perimeter season discharge perimeter perimeter m3/s m m3/s m3/s m % S1 Rapid 25 29.4 2 2 7.88 73 5 5 11.19 62 8 8 21.34 27 Pool 25 108.8 2 2 101.10 7 5 5 103.66 5 8 8 105.62 3 S2 Rapid 26 43.7 2 3 20.08 54 5 6 31.11 29 8 9 34.19 22 Pool 26 Data not available S3 Rapid 33 23.3 2 15 10.29 56 5 18 11.69 50 8 23 31.10 46 Pool 33 28.4 2 15 21.98 23 5 18 22.74 20 8 23 23.50 17 S4 Rapid 34 27.5 2 17 25.6 6.9 5 20 26.2 4.7 8 25 27.1 1.5 Pool 34 34.9 2 17 12.16 65 5 20 18.56 47 8 25 29.22 16 Riparian Release 83 EAMP Main Text Table 3.43: Impacts on Fisheries Production for different riparian releases make decisions on management objectives and approaches to flow % Reduction in Fish Productivity for Different Riparian management based on analysis and modeling provided by NTPC. Waterbody Release Compensation 2 m3/s 5m3/s 8m3/s NT mainstream 60 50 30 Thecurrentunderdevelopmentofaquacultureinthecommunities highlights a significant opportunity to develop and expand aquac- TH Headpond 0 0 0 ulture activities as part of a compensation strategy. Compensation Nam Phao 35 30 20 may also take the form of providing capacity building in fisheries Nam Ngoy 10 10 10 management in the Nam Theun basin. Encouraging abandonment of destructive fishing techniques and replacing these with sustain- Nam Gnouang 10 10 10 able fishing practices will compensate to some extent the reduc- Ponds/rice Dependant on Dependant on Dependant on tion in fish abundance caused by the Project. fields tributary tributary tributary The compensation entitlements of the project affected persons and the process of compensation are presented in detail in the SDP. re-establishing pool-riffle morphology, modify the downstream edge of low velocity pools to increase outflows; (v) in long, deep Community Consultation pools current deflector may be appropriate to increase hydraulic A disclosure and consultation program will be implemented in diversity to improve the habitat complexity and to develop erosion all the potentially affected villages with the objectives to (i) obtain areas; and (vi) increase the habitat complexity for fish; including more quantitative socio-economic data; (ii) conduct an awareness selectively placing large boulders in pools, fish shelters to protect program in advance of dam closure to prepare communities for fry and smaller fish and large logs or other woody debris could be the potential impacts; (iii) elicit potential affected persons con- placed strategically. cerns; and identify further mitigation measures. The implementation of specific channel morphological techniques Similar methodologies to those used for the consultation process will require (i) a more accurate topographical study of the river in communities along the Xe Bang Fai will be adopted, details of profile; and (ii) a detailed assessment of important fish migration which are presented in the SDP. and spawning zones in the Nam Theun. However, the impacts of periodic flooding events are expected to significantly alter any Monitoring Impacts channel morphological techniques that are implemented. Adaptivemanagementwilldeterminehowthetotalvolumerelease Adaptive Management should be managed to maintain the predetermined, valued use objectives for the ecosystem. Predetermined use objectives, reflec- Because there is some degree of uncertainty in the assessment of tive of the intended ecosystem condition, will be used to measure the impacts, adaptive management of the 2 m3/s riparian release and assess the effectiveness of the riparian release regime. With and complementary 5 MCM will be adopted. The adaptive man- the outputs of this monitoring, the management strategy of the agement of the riparian release will have the flexibility to respond release can revised, while maintaining the same total volume of to monitoring and evaluation of the environmental performance water. A monitoring and evaluation approach will be the driving of the release regime. This will be an iterative process, repeated as force for optimizing the riparian release regime within the same long as it takes until the system stabilizes. total of water. The following monitoring programmes have been The adaptive management will cover two main periods of time, identified in the CA. construction (including dam construction and impoundment) and The WQMAP will include sampling stations on the Nam Theun operation. It will typically involve the following steps: (i) proactive to monitor the evolution of water quality released from the Nakai experimentation, (ii) monitoring, (iii) reevaluation and experimen- Dam site. Sufficient monitoring will be conducted prior to the clo- tal design, (iv) decision making involving multiple stakeholders. sure of the dam to obtain adequate baseline. The water quality Theproactiveexperimentationwilltesttheimpactofdifferentflow monitoring shall continue during the first five years of operations regimes on the downstream areas, within the operational limits of to determine whether the potential effects of increased retention the riparian release and the modification of the morphology of the time in the pools are disturbing or adversely affecting aquatic life river. The monitoring will focus on water quality, flow and fisher- and wildlife population. An indication of parameters, sampling ies and this will be used to help optimize and test flow regimes. frequency and locations of the WQMAP is presented in Chapter The monitoring data and modeling of the habitat, water quality, 3. hydrology and potentially ecosystems of this area will be used Amonitoring program will be developed to enable NTPC to deter- to test and refine flow and habitat management approaches. An mine the ecosystem values and components of the Nam Theun "environmental flow commiee" including the EMO, the WMPA downstream of the Nakai Dam. To enhance biodiversity and pro- and local village reselement commiees representatives will ductivity, further studies shall be undertaken as part of the adap- Table 3.44: Trade-off analysis of different riparian release regimes Riparian Release Value of Fisheries Value of Aquatic Value of Aquatic Value of reduction Cost of Addition Loss Product Loss Ecosystem Total of loss Discharge m3/s NPV MUSD NPV MUSD NPV MUSD NPV MUSD NPV MUSD NPV MUSD 2 1.172 0.004 1.26 to 2.11 2.436 to 3.286 5 1.005 0.003 1.26 to 2.11 2.268 to 3.118 0.168 45 8 0.689 0.002 1.26 to 2.11 1.951 to 2.801 0.485 72 84 Riparian Release EAMP Main Text tive management process; such as a seasonal study of hydrology Nam Theun & Nam Kading and aquatic tropic dynamic. As part of the adaptive management process, the monitoring pro- Dry Season gramme shall be such to enable NTPC to determine productivity Temperature in the Nam Theun on the Nakai Plateau was meas- in fish populations downstream of the Nakai Dam during the first ured at 17-22° C for December to February, and at 20-28° C in five years of operations. March. Continued warming of the river occurs in April, with tem- The GOL and NTPC shall review the results of the studies. If nec- peratures reaching 31° C. essary, based upon the results from the water quality and produc- The Nam Theun basin is primarily situated on a sedimentary/ tivity/diversity monitoring recommendations on the management sandstone bed within the reservoir area, and therefore measures of the riparian and complementary releases will be made. of alkalinity (0.3-25.0 mg/l as CaCO3), total hardness (7-9 mg/l Intra-basin Coordination CaCO3), and total dissolved solids (4-76 mg/l) are in the low to normal range. Magnesium concentrations are less than 2 mg/l in The establishment of a Nam Theun/Nam Kading River Basin the basin. Calcium concentrations are less than 5 mg/l in the Nam Commiee is planned to help facilitate close cooperation between Theun, and less than 8 mg/l in the Nam Kading. Measures of chlo- NTPC, THPC, TH Extension, and potential other projects, and ride, sodium, and potassium are also low (< 4 mg/l). These rela- GOL. Coordination of environmental impacts assessments, moni- tively low values are most likely due to the lack of mineralisation toring, mitigation and compensation activities between the differ- in the basin. ent agencies will benefit both the environmental and social compo- Conductivity is low (2-90 µS/cm) from December to July in the nent of the Nam Theun/Nam Kading basin. basin. SMEC recorded conductivity values ranging 280-430 µS/cm in the Nam Kading in February and April of 1990, while meas- Water Quality urements in the Nam Theun were within the range of 2-90 µS/cm during the same period (SMEC, 1991). The elevated conductivity Water from the Nam Theun will be stored in the Nakai Reservoir values recorded in the Nam Kading, compared to the Nam Theun, before being released into the Nam Kathang and the Xe Bang Fai. were probably a result of inputs from the populated Nam Phao There will be changes in the water quality during this storage and the low values for the Nam Theun, a result of the lack of min- Impacts period that will consequently affect water quality parameters in eralisation in the basin. the Nam Theun, the Xe Bang Fai, the Nam Kathang, and poten- Values for pH range widely from 5.8 to 8.9 (SKM, SMEC, Norp- tially in the Mekong River downstream from the mouth of the Xe lan, TEAM). Generally, pH of the water during the dry season is Bang Fai. The following analysis presents the existing water qual- slightly basic (7.2). ity data, and the potential changes in water quality, of the Nakai Reservoir and of the rivers impacted, based on computer simula- Turbidity is very low in the Nam Theun basin (1-12 Nephrometric tions for the reservoir and on a model of evolution of dissolved Turbidity Units (NTU)), indicating the absence of a large sediment oxygen for the water released into both the Nam Kathang and the or algal load carried by the river during the dry season months. Xe Bang Fai. The analyis provides the best estimate of what will This is confirmed by low total suspended solids (1-12 mg/l). happen to water quality in the reservoir and the affected rivers. Dissolved oxygen in the Nam Theun/Nam Kading normally Annex G presents the water quality modelling assumptions and ranges between 5-12 mg/l. This falls within normal ranges, and results in more detail. corresponds with relatively low chemical oxygen demand values Aer the analysis of impacts, the section presents an evaluation of of under 6 mg/l. management and mitigation measures, including steps to reduce Nutrient concentrations are low in the Nam Theun. Total nitro- biomass in the inundation area and the incorporation of aeration gen in the water is generally 10 µg/l in the area upstream of the structures into the Project design. Finally, the section outlines a proposed Nakai Dam site. Total nitrogen in the Nam Theun/Nam plan to implement a monitoring programme to gather baseline Kading stretch was more than ten times higher (98-190 µg/l). Nor- data and assess any change in water quality during Project con- mally, nutrient contents of rivers are higher as the river descends struction and operation. from it origin. Consequently, an increased nutrient content in the Nam Kading would be expected. Total phosphorus at all sites Baseline Surface Water Quality was less than 20 µg/l. Low phytoplankton density (less than 5.8 x Water quality sampling data is available for the Project area for 106 cells/m3), low chlorophyll a (less than 2 µg/l) and the absence of the months of February and April 1990 (SMEC, 1991), February frequent blue-green (Cyanophyta) algal blooms is associated with and March 1995 (TEAM, 1995), December 1996 (SKM), April and low nutrient content in the water. May 2001 (HYDRECO, 2001a), September and November 2001 Fecal coliform bacteria were found to occur at a concentration of (EDF, 2001 and HYDRECO, 2001b) and March 2002 (EDF, 2002). In 0-3 per 100 ml of Nam Theun water, and 6-24 per 100 ml in the addition, data was collected on the Nam Theun and Nam Kading Nam Kading. Elevated fecal coliformsin the Nam Kading may, as below the Nakai Dam site within the Theun Hinboun Project area with conductivity, be related to human and animal activity in the in December 1994, March, April and July 1995 (Norplan, 1995). lower river basin. Monthly water quality data has been collected since 1985 at the Dioxin and Polychlorinated Biphenyls (PCB) concentrations bridge crossing the Xe Bang Fai on Road 13, as part of the MRC in Nam Theun fish samples taken for the Nam Theun Hin- water quality monitoring network. A summary of water quality boun Impact study were found to be low (16.6 pg TE/g fat) data from the Nam Theun, Nam Kathang and Xe Bang Fai col- (NORPLAN, 1994). The measurements of dioxin and PCBs in fish lected during the dry season and wet season of 2001 is presented tissues are quite low and it is expected that the concentrations in Table 3.45. A monitoring programme starting early in 2004 will of these compounds in the Nam Theun reservoir area would be extend this existing baseline data and further the knowledge of approximately the same. water quality dynamics before the start of construction and opera- Although the risk of war-time heavy metal pollutants in the Nam tion. More details on the monitoring programme are provided Theun has been suggested (NORPLAN, 1995), results of metal later in the section. analyses indicate low concentrations (less than 0.50 µg/l for lead, Riparian Release 85 EAMP Main Text Table 3.45: Summary of water quality in the Nam Theun, Nam Kathang and Xe Bang Fai during 2001 (Hydreco 2001a and b) Nam Theun/Nam Kading Nam Kathang Xe Bang Fai Parameter Wet Season Dry Season Wet Season Dry Season Wet Season Dry Season Temperature (°C) 23.6 ­ 24.7 25.6 26.5 ­ 28.0 27.3 ­ 35.7 26.8 ­ 27.0 28.4 ­ 33.1 pH 6.45 ­ 6.52 7.23 7.24 ­ 7.50 7.55 ­ 8.50 7.48 ­ 7.73 8.10 ­ 8.40 Conductivity at 25°C (µS/cm) 28.7 57.4 205 320 329 322 Dissolved oxygen (mg/L) 6.7 ­ 7.1 6.5 7.7 ­ 7.8 4.6 ­ 14.1 6.4 ­ 7.2 6.2 ­ 9.4 Suspended matter (mg/L) 9.4 ­ 9.4 ­ 39.3 ­ Ammonium (mgN/L) 0.02 0.04 0 0.04 0.02 0.04 Nitrites (mgN/L) 0.004 0.001 0.005 0.005 0.019 0.010 Total phosphorus (mgP/L) 0.15 0.09 0.20 0.11 0.19 0.10 Silicon (mgSi/L) 4.4 4.5 4.8 9.7 3.6 11.1 Calcium (mgCa/L) 0.31 0.85 0 ­ 0 ­ Magnesium (mgMg/L) 2.88 1.50 0.81 ­ 0 ­ zinc, copper, cadmium and arsenic). Manganese and iron levels (131-149 mg/l as CaCO3) are approximately an order of mag- were found to be 2 and 94 µg/l, respectively. The higher concen- nitude higher than in the Nam Theun. Measured conductivity trations of iron may be due to the periodic acidic situations in the ranges from 11 to 36 µS/cm. Conductivities recorded inApril, 2001 Nam Theun. Acid in the water will facilitate iron dissolution into (HYDRECO, 2001a) were between 20 and 39 µS/cm. the water column. Water temperatures in the Xe Bang Fai basin range from 21 to Wet Season 33° C. Wet season water quality results (EDF, 2001; HYDRECO, 2001a) Measured dissolved oxygen levels ranged from 3.0 mg/l to from tributaries of the Nam Theun were characterised by a rela- 10.8 mg/l during sampling in 1995, and appear to be generally tively low pH (6.5) but with low conductivity (28.7 µS/cm). The lower than those in the Nam Kading/Nam Theun basin. The lowest acid soils of the Plateau are derived primarily from the pine for- oxygen level (3.0 mg/l) was measured in the Nam Phit which had Impacts est that used to be present on the Plateau. Wet season measure- no water flow during the dry season at the time of sampling. In ments during flood events would therefore likely decrease the the dry season, water in the Nam Phit close to the confluence with pH values, whereas during the dry season values as high as the Xe Bang Fai consists only of stagnant backwaters from the Xe 7.2 have been recorded. The seasonal trend in the Nam Theun Bang Fai. Chemical oxygen demand measurements were consider- water quality probably occurs because of the differences in dis- ably higher at the mouth of the Nam Phit (98 mg/l), where oxidiz- charge regime between the dry season and the wet season. able compounds accumulate in lower discharge conditions, than HYDRECO (2001a) also found that the waters of the Nam Theun at other sites in the Xe Bang Fai, where chemical oxygen demand are relatively warm (24.1°C),andhadgooddissolvedoxygensatu- ranged from 2-38 mg/l. Mean dissolved oxygen levels measured at ration (7 mg/l). The waters were not very clear; Secchi disk read- the bridge of Highway 13 downstream in the Lower Xe Bang Fai ings of less than one metre were recorded. The main tributaries were 7.7 mg/l in 1995, which compares with the mean dissolved (Nam On and Nam Xot) distinguish themselves from the main oxygen concentrations of 7.5 mg/l, measured in the Mekong main- river by lower conductivities and higher concentrations of dis- stream at Nakhon Phanom (Mekong Secretariat, 1997). Measure- solved oxygen. Only the Nam Nian presents characteristics similar ments of dissolved oxygen levels made in 1995 at 22 stations from to the Nam Theun. Mahaxai to the Mekong confluence ranged from 5.7 to 7.1 mg/l, In summary, the water quality of the Nam Theun is relatively and generally indicate good water quality. This good water qual- good,withhighdissolvedoxygen,andlowconductivityandnutri- ity was confirmed by the water quality evaluations conducted by ents. This reflects the fact that the river is located in a relatively HYDRECO (2001a). They recorded dissolved oxygen concentra- undisturbed catchment with a relatively small number of people tions between 4.6 to 14.5 mg/l in April 2001. engaged in shiing cultivation, and no industry of any type. Turbidity in the Xe Bang Fai ranged from 14 to 23 NTU during the period January to March, 1995 at the various locations sampled. Xe Bang Fai, Nam Kathang & Nam Phit The concentration of total suspended solids ranged between 0.4 Dry season and 23.0 mg/l during the 1995 dry season. Phytoplankton density is relatively low (less than 3.2 x 105 cells/m3 The water quality in the Xe Bang Fai basin is good. It shows higher at Mahaxai in February 1995) with a variety of algal groups repre- measures of alkalinity, total hardness, conductivity and total dis- sented. Additional chlorophyll a measurements were collected in solved solids than the Nam Theun basin, and reflects the fact that April 2001 (HYDRECO, 2001a). These concentrations ranged from the Xe Bang Fai is primarily situated on a limestone bed. The Xe 0.9 to 13.6 µg/l and represent low to moderately enriched aquatic Bang Fai flows through numerous villages where most of the peo- systems. ple are involved in agricultural and fisheries activities. During the dry season, riverbanks are used for growing vegetables. Livestock Wet Season and the human population also use river water for bathing and The Xe Bang Fai (at Mahaxai), the Nam Kathang and the Nam drinking water. Phit were sampled during September 2001 (HYDRECO, 2001b). In During the dry season in the Xe Bang Fai, pH ranged from 6.3 the wet season, the water quality of the Xe Bang Fai appears to to 8.4 (HYDRECO, 2001a). Measures of total dissolved solids be fairly good. Conductivity measurements ranged between 13 to (124-204 mg/l in February 1995 and 191-241 mg/l in March 38 µS/cm, pH was between 7.2 to 7.8, while dissolved oxygen con- 1995), alkalinity (109-174 mg/l as CaCO3), and total hardness centration was between 6.4 and 7.2 mg/l. Nutrient concentrations 86 Riparian Release EAMP Main Text were generally low, though orthophosphate concentrations would such as: i) the decay of residual above and below-ground biomass; easily support phytoplankton growth. ii) the thermal stratification; iii) the resistance to oxygen transport HYDRECO (2001b) concluded that the Xe Bang Fai wet season fromsurfacetodepth;iv)theoxygenandnutrientloadingfromthe waters present different characteristics to those of the Nam Theun, inflowing rivers; v) phytoplankton dynamics; and vi) the detailed with adequate dissolved oxygen but low conductivity. The water circulation paerns leading to differential residence times within tends to be warmer, slightly alkaline, and contains considerably various sectors of the reservoir area. more orthophosphates and total phosphorus. Assumptions regarding the calibration of the model and the basic Baseline Groundwater Quality input parameters are described in detail in Annex G. It should be noted that the organic maer discharged from the power station A description of the geological formations within the Project area is not indicated in the analysis and the model does not take into is provided earlier in the chapter. In the Phra Wihan formation, account the presence of any oxygen consuming gases in the tur- groundwater quality is suitable for most purposes, with gener- bined water. A re-evaluation of the water quality modelling was ally less than 1,000 mg/l total dissolved salts in the dry season. done in 2000 to take into consideration a number of design and Contamination of the aquifer close to the weathered surface of operational changes made to the operation of the Project. The new the formation can happen through the lateritic profile. However, model verified the validity of the past numerical study with six unweathered rock units in this formation protect the aquifer from turbines in the power station (Romero et al., 2000), and evaluated contamination. the dominant phytoplankton characteristics and conditions likely In the Khok Kruat formation, groundwater quality is suitable for to result in algal blooms during the periods of dam construction all purposes. However, salinity ranges up to 2,000 mg/l in the dry (year 1), reservoir filling (year 2), and elevated levels of terrestrial season. biomass decay in the reservoir (years 1-3) and the subsequent Analysis of ground water in the reselement area, which over- seven years. The basic assumptions used in the 1997 water quality lays both the Phra Wihan and Khok Krut geological formations, model were reintroduced into the new model. found conductivity to be between 87 µS/cm to 388 µS/cm; pH was A number of different operating scenarios were modelled for the between 6 and 7.8; NO3-N was between 0.006 to 0.096 mg/l; NH4-N Nakai Reservoir. Comparisons of the water quality at the entrance was between 0.070 to 0.097 mg/l and turbidity was between 6 and to the power tunnels, spills at the dam and riparian releases from Impacts 27 NTU (STS, 2001). Quality is good because the overlying sandy the dam were simulated with the revised water quality model. layers filter the water as it passes to the surface aquifer. The revised model considered the following conditions: i) ten-year In the Maha Sarakham formation located in the middle of the periods of high flow; ii) ten-year periods of low flow; iii) three tur- Nakai Plateau, most of the rocks are likely to have gypsum or even bines operating; iv) six turbines operating; v) biomass as predicted halite saturation. As a result, salinity increases from 7,000 mg/l to in the study by Prosser (1997); and vi) potential for catchment deg- over 100,000 mg/l with depth at any time. The groundwater from radation from logging or development. this formation is essentially contaminated. The one-dimensional simulations conducted with the For the alluviums near the middle of the Nakai Plateau, ground- DYRESM-WQ model were coupled with the CAEDYM model to water is generally of goodquality.Salinityrangesfromzerotoonly predict the vertical variations in stratification, nutrient cycling, 500 mg/l in the dry season. phytoplankton production and the oxygen dynamics within the reservoir on seasonal and long-term time scales. The three-dimen- In the Phu Kradung formation situated below the Plateau in the Gnommalat area, groundwater quality is suitable for most pur- sionalELCOMmodelwasusedtopredictthegeneralcirculationin poses. Many communities already use groundwater from this the basin in response to representative wind and inflow regimes. formation for domestic purposes. Salinity ranges from zero to In particular, the likelihood of preferential advection of: i) low oxy- over 1,000 mg/l. Groundwater quality is generally acceptable. The gen deep water during high wind events; or ii) turbid, nutrient exceptions are in the limited areas subject to leaching of gypsum rich flood discharges to the reservoir and to the power intake tun- from deposits where the groundwater becomes too salty for use, nels were investigated with ELCOM. The three-dimensional water up to 7,000 mg/l. quality simulations with high inflows and high winds using the ELCOM model were coupled to the CAEDYM model. The linked Predicted Water Quality in the Nakai Reservoir & models were designed to determine whether specific current pat- Impacts terns were generated to the power intake tunnels. Input data for these models was obtained from site measurements, and aug- Models & Assumptions mented from existing scientific literature as reported by Winters A simulation of water quality in the Project reservoir was con- et al. (1997). ducted in 1997 using the one-dimensional water quality model Results of Water Quality Modelling DYRESM-WQ for averaged long-term predictions of water qual- ity and a three dimensional model ELCOM (Winters et al., 1997). Water Temperature These models assessed the longitudinal variation in water quality The reservoir is expected to be thermally stratified each year from along the reservoir over the critical first few years of operation. late dry season, just prior to the wet season when solar radiation The one-dimensional DYRESM-WQ model was developed by the is greatest. Vertical temperature gradients will likely be greatest Center for Water Research, University of Western Australia and between about 5-10 m depth from the surface of the reservoir, has been used to predict water quality conditions for hydropower even when the reservoir is at its minimum operating level. The projects and lakes throughout the world, including the Bakun onset of thermal stratification generally occurs as water surface Hydroelectric Project, Malaysia (Lewis, 1995), Lake Pamvotis, levels approach the seasonal minimum water level in late dry Greece (Romero et al., 1999) and Lake Burragorang, Australia (Jha season. The thermal stratification will be maintained through et al., 1999). the first months of the wet season when the water surface rises A variety of dominant processes were identified as potential rapidly with the onset of wet season discharge to the reservoir sources that would affect water quality in the Project reservoir, (Figure 3.41). Riparian Release 87 EAMP Main Text At the end of the wet season, stratification weakens as solar radia- tion becomes less and the water temperature of the inflow water decreases. Then, when the surface level of the reservoir nears the seasonal maximum, water temperature in the reservoir will likely become nearly homogeneous with relatively cool water tempera- ture (between 15 and 20° C). Maximum water temperatures at the surface of the reservoir, particularly when the reservoir is drawn down to its minimum seasonal level, could be approximately 30° C with boom temperatures ranging between 20 and 25° C. Dissolved Oxygen Periodic episodes of low dissolved oxygen (< 2 mg/l) were pre- dicted to occur in the deeper waters under thermally stratified con- ditions (Figure 3.41). Anoxic conditions generally lasted for one to three months, and because of the shallow nature of the reser- voir these anoxic conditions affected less than 3% of the reservoir volume. The evolution of anoxic conditions in the boom water generally occurs immediately prior to the onset of the wet season. Figure 3.41: Predicted temporal and spatial variations in temperature (top) The period of stratification seems to respond to the amount of and dissolved oxygen (bottom) in the Nakai Reservoir suspended sediment that is discharged to the reservoir from the tributaries. The increased suspended sediment load facilitates the reactive. Biochemical and chemical oxygen demand will elimi- absorption of solar radiation and tends to inhibit the mixing of sur- nate all of the oxygen from the water in three days (HYDRECO, face and boom waters. 2001a). The impounded area of this dam had residual biomass at When stratification was evident in the reservoir, nutrient concen- the time of impoundment. Some of the biomass was burnt before trations and chlorophyll a appeared to be moderate in concentra- inundation, making nutrient readily available in the initial years. tions and the productivity of the reservoir was at mesotrophic lev- Residence time of water in the reservoir is about the same as that els. expected for the Nakai Reservoir, but the Nam Leuk reservoir is The dissolved oxygen concentrations in the dry season through deeper than the Nakai Reservoir. In April, the slightly older Theun Hinboun reservoir, impounded Impacts the power tunnels, along with spillage of water from the dam and the riparian release, appeared to have dissolved oxygen concen- in 1997, had dissolved oxygen concentrations of 6.1 mg/l in the tail- trations above 5 mg/l and low nutrient concentrations. However, race water discharged from the power station (HYDRECO, 2001a). during the initial years of operation, when decomposition rates of The Theun Hinboun headpond was created within the existing inundatedbiomasswerehigh,nutrientconcentrationsinthepower river banks so there was no requirement to flood large amounts of tunnels, riparian release and spills through the dam, appeared to vegetation. The reservoir area is smaller and consists only of a weir have relatively high concentrations. This is to be expected as de- to divert water to the power tunnels and power station. Conse- composition of organic maer in the reservoir area proceeds. quently, water quality downstream from the power station is fairly good. Dissolved Oxygen in Other Regionally Relevant Reservoirs DatafrompresentlyconstructedprojectsinLaoPDRand alsofrom Dissolved oxygen concentrations downstream from existing reser- modelling conducted by Winters et al. (2000) on the Nakai Reser- voirs (Nam Ngum, Theun Hinboun, Nam Leuk) were reviewed by voir indicates that dissolved oxygen concentrations will increase HYDRECO in 2001a to anticipate some of the potential problems over time but will be affected by the presence of vegetation in the that may emerge at the Nakai Reservoir and downstream of the reservoir area for several years. In the early years of operation in Power Station. these other projects, water discharged from the power stations Aer thirty-five years of operation, water quality of the Nam may be low in dissolved oxygen and high in reducing elements Ngum Power Project is fairly good. However, some anoxic water is (e.g. methane and hydrogen sulphide as well as other reducing found at the boom of the reservoir, but mostly below the intakes chemicals). Over several years of operation, the concentrations of for the Power Station. Frequently, the water discharged from the reducing compounds diminish and dissolved oxygen concentra- power station has low dissolved oxygen concentrations (3.5 mg/l tion increases. on average). However, downstream from the dam, the dissolved oxygen concentrations gradually increase. Methane concentra- Ammonia & Sulphide in the Nakai Reservoir & Other Regionally tions are low. The biochemical and chemical oxygen demands in Relevant Reservoirs the water discharged from the power station are fairly low and Peak concentrations of 25 µg/l ammonia are predicted to occur do not impact oxygen concentrations significantly (HYDRECO, during the wet season aer destratification of the reservoir. These 2001a). concentrations are close to the baseline values for receiving waters, In 2001 water quality problems continued to exist at the Nam Leuk and are not expected to have a significant impact on fish popula- reservoir, impounded in 1999. The reservoir is anoxic from a depth tions. of approximately 10 m to the boom of the reservoir. Discharge Samples of water discharged from the power station at Nam Leuk from the power station indicates ferric oxidation and at times there indicated that some ammonia is present in the water (> 0.3 mg is an odour of hydrogen sulphide. In the dry season, the water N-NH4/l). The water discharged from the Theun Hinboun power discharged from the power station is mostly anoxic with less than plant is oxygenated and ammonia concentrations are low. Water 0.5 mg/l of dissolved oxygen and a fairly high concentration of dischargedfromtheNamNgumreservoircontainsasmallamount dissolved methane (5 mg/l). Aer passage over a simple aeration of ammonia (maximum 0.1 mg N-NH4/l) (HYDRECO, 2001a). weir constructed from gabions, the dissolved oxygen increases to Due to the continuous high oxygen levels in the epilimnion, no about 3 mg/l and the methane concentration is reduced by about impacts of hydrogen sulphide are expected at the surface water 3 mg/l. The water discharged from the power station is highly layer. The water quality model (Winters et al., 2000) predicts strati- 88 Water Quality EAMP Main Text fication of the reservoir. Anoxic conditions will likely arise in the Experience from Other Hydro-Electricity Dams in Southeast Asia hypolimnion but this water will not be diverted for riparian release into the Nam Theun downstream of the Nakai Dam. For the Power A large number of hydroelectric dams have been constructed throughout Southeast Asia. Information relevant to the Project Station intake, water will be diverted from both the epilimnion and can be gained from briefly examining these already constructed hypolimnion, reducing the concentrations of hydrogen sulphide dams. Water quality issues associated with these dams include: and methane. Fish egg survival and fish fry development are par- i) large rates of sedimentation because of basin characteristics and ticularly vulnerable to hydrogen sulphide (Boyd, 1979). management; ii) changes in flow volume to downstream reaches; Other Water Quality Factors iii) poor water quality discharges downstream; and iv) aquatic plant proliferation. The first two issues have been discussed earlier The desirable pH range for good fish production is between 6.5 in the chapter. and 9 (Boyd, 1979). Predicted pH values for the Nakai Reservoir arewithinthisrange.Photosynthesisremovescarbondioxidefrom Downstream Discharges water during daylight, causing a rise in pH. When there are phy- Generally in Southeast Asia, only during the wet months are toplankton blooms in the Nakai Reservoir, the pH may increase hypolimnetic releases of water from storage reservoirs acceptable significantly because the water in the reservoir does not have buff- fordownstreamaquaticlife.Coolerairtemperaturesandwindand ering capabilities. During the night, carbon dioxide concentrations wave action during each wet season mix and destratify reservoirs, will likely increase due to respiration by the phytoplankton and leading to higher dissolved oxygen concentrations and good water other aquatic organisms. When this occurs, the pH will decrease quality throughout the water column. During the dry season, ther- as carbon dioxide neutralises some of the ionised compounds in mal stratification of the water column occurs. the reservoir. Following a review of 30 reservoirs with dams higher than 15 m Nutrient concentrations in the Nakai Reservoir will increase dur- in lower Mekong countries, Bernacsek (1997) indicated that most ing the first few years of operation due to the decomposition of reservoirs suffer from hypolimnion de-oxygenation and hydrogen plant material that is present in the reservoir area. This is a com- sulphide production. Thus any discharge structures or turbine mon phenomenon in reservoirs throughout the world and results intakes situated 15 m below the water line are likely to discharge cool and oen toxic water downstream. Despite this knowledge, in an initial flush of productivity until the reservoir matures and and the fact that the ability to destratify reservoirs with in-lake Impacts the amount of decomposing plant material declines.An increase in aeration has been well documented, it appears that many of these nutrient concentrations frequently leads to phytoplankton growth dams release hypolimnetic waters without adequate re-aeration in the reservoir. High nutrient levels are expected within reservoirs devices downstream to improve water quality. To date, there with insufficient removal of vegetation before impoundment. A appears to be no suitably designed destratification units working consequence of the higher nutrient concentrations is that pH will in Southeast Asian reservoirs, and lile or no mitigation measures fluctuate considerably in the reservoir until the nutrient concentra- to improve downstream water quality from these reservoirs. One tions come into balance with the water flowing into the reservoir or two exceptions exist, including the simple gabion aeration weir area. The fluctuation in pH could affect fish production and could built downstream of the discharge of the Nam Leuk reservoir. result in stress and diseases in the fish populations residing in the In2001,theseasonalevolutionofwaterqualitywithintherecently- reservoir area. constructed Nam Leuk reservoir was investigated by HYDRECO. Any increase of the sedimentation process may cause a significant This was conducted to provide local input data for the numerical negative impact on the reservoir fish. Given the relatively undis- methane water quality model for the project and to confirm some turbed nature of the catchment, suspended sediment concentra- of the water quality predictions of the modelling undertaken for tions in the Nakai Reservoir are expected to be quite low, with no the Nakai Reservoir. Water column profiles taken in the dry season impact to fish populations. from the Nam Leuk reservoir showed that the lower half of the water body was lacking in oxygen a year and a half aer being Agriculture activities in the reselement areas may lead to an filled. The water discharged from the power station, deoxygenated increase in the use of pesticides, which are extremely toxic to fish (< 0.5 mg/l) and enriched in dissolved methane, flows over a weir, and can lead to bio-accumulation to levels harmful for human con- giving a gain of 3 mg/l of dissolved oxygen. The dissolved oxygen sumption concentration averages 4.8 mg/l some 12 km downstream of the Conditions created in the Nakai Reservoir in the initial years could power station, just prior to mixing with the Nam Ngum Reser- promote the methylation of inorganic mercury, bound to particles voir (HYDRECO 2001a). The simple aeration weir at Nam Leuk is and organic substances, to methyl-mercury. Methylation rates are constructed from gabions that, when the power station is operat- elevated under anoxic conditions and in the presence of organic ing, create a drop of approximately 1m during the dry season. In maer, which stimulates growth of microbial populations. Methyl- the wet season, the aeration weir efficiency decreases due to the mercury is readily accumulated by aquatic organisms, especially increased turbine discharges and higher downstream levels. through the gills of fish, and can biomagnify in higher trophic lev- Further measurements at the end of the rainy season showed an els, leading to potentially harmful concentrations for humans. improvement in water quality, due to the increased speed of water Supersaturation occurs when water and air mix under pressure renewal. The thickness of the oxygenated layer in the Nam Leuk and can impact fish at the lethal and sub-lethal level. Conditions reservoir increased by approximately 5 m and in particular, the created when spill water drops from the top of a dam causing air water quality at the turbine outlet was considerably improved, bubbles to mix with water at depth can result in supersaturation. with an oxygen level of 3-5 mg/l. The Nakai Dam will feature a drop of only 40 m, together with a Aquatic Macrophytes shallow stilling basin and a shallow Nam Theun below. This com- Excessive development and proliferation of aquatic macrophytes bination should not result in a significant impact from supersatu- could affect water quality in the reservoir. Such proliferation could ration. An analysis of the potential for supersaturation below the be caused by nutrient enrichment, or simply when introduced Nakai Dam is to be included in the analysis of the riparian release species have no natural predators or diseases, even in oligotrophic and spills. conditions.Anumber of species of aquatic macrophytes have been Water Quality 89 EAMP Main Text recorded in the Nam Theun and Nam Kading. Of particular sig- the Nam Kathang, the downstream channel and the Xe Bang Fai, a nificance is the presence of water hyacinth (Eichhornia) and water modelwasdevelopedbyEDF(2001).Themathematicalmodelcon- leuces (Salvinia and Pistia) in the basin. Only Eichhornia has been sistedoftheLIDOhydrauliccode,usingtheSaint-Venantequations recorded in the Nam Theun basin. in one dimension, the Tracer transport soware, and the EUTRO The Nam Ngum Reservoir was filled in 1972. A report completed water quality modulus, which models river eutrophication proc- on the Development and Management of Fisheries in Nam Ngum esses. The model was designed to investigate the potential impacts Reservoir found the occurrence of dense growths of Azolla, Sal- causedbyreleasesfromtheProjectondissolvedoxygenconcentra- vinia, Pistia and Eichhornia. These dense growths occurred only in tions in the Nam Kathang and the Xe Bang Fai. Three sets of results several embayments in the reservoir during the four-year study were used in the analysis: i) the updated CWR results of the water period. Other potential weeds are the submerged macrophytes quality modelling for the Nakai Reservoir (Romero et al., 2000); Hydrilla and Ceratophyllum. Hydrilla verticillata was found in the ii)assumptionthatthewaterqualitywillbesimilartothatobserved Nam Ngum reservoir and grew abundantly in shallow areas in the first years of operation at the Petit Saut Hydropower Project 3-5 m from the shore and up to 4 m in depth. This plant could ham- inFrenchGuyana;andiii)assumptionthatthewaterqualitywould per fishing and navigation in the shallower regions of the reservoir be beer than at Petit Saut but not as good as the water quality (Interim Commiee for Co-ordination of Fisheries in the Lower predicted by CWR. The Petit Saut scenario assumes water quality Mekong Basin, 1984). much inferior to that predicted for the Nakai Reservoir.Asensitiv- ity analysis was performed to take into account uncertainties such It is likely some submerged aquatic plants will become established as characteristics of the water discharged from the Power Station, in the Nakai Reservoir. However the 12.5 m vertical fluctuation the efficiency of the planned aeration systems and the self-purifi- of water level on a seasonal basis should limit submerged and cation capacities of the rivers. Other variables have been derived emergent macrophyte growth, and a balanced population could from water quality data collected from the Nam Leuk reservoir. improve fish production by providing refuge and forage habitat (Bernacsek, 1997). This author reports that outbreaks of aquatic At Petit Saut, dissolved oxygen concentrations of zero were macrophytes frequently occur during the first year or two of observed in water discharged from the dam for a much longer operation of impoundments in the Mekong River Basin, oen as period than what is expected to occur from the Project. The Petit a consequence of the concentrations of nutrients that are gener- Saut analysis indicated the presence of oxygen-consuming gases ated when the reservoir is first filled. Biological control methods (such as methane) in the water discharged from the turbines, in for Salviniahave provedto be successfulin Papua New Guinea and concentrations of up to 3 mg/l downstream of the aeration struc- Australia. Water hyacinth control in smaller lakes is labour inten- tures, whereas the CWR analysis did not indicate the presence of such gases in the turbined water. Other physico-chemical variables Impacts sive and booms are used to collect this material. used for the Petit Saut analysis were from measurements made Changes in vegetation community structure, species composi- during its first few years of operation. The Petit Saut analysis tion and biomass quantities are likely to occur in the downstream assumed an oxidizable organic material load of 8 mg/l in the water Nam Theun. Macrophyte communities are likely to be similar to discharged from the turbines. This is four times more than the oxi- those communities presently in the river. An assessment of the dizable load predicted for the Nakai Reservoir (2 mg/l). Overall, impacts on the macrophyte communities in the Nam Theun is to the Petit Saut scenario took into account oxygen-consuming gases be included in the analysis of riparian release in the dry season and had a greater organic load resulting in poorer water quality in of 2004. The submerged macrophytes, Hydrilla and Ceratophyllum the water discharged from the turbines. One of the driving forces and the emergent macrophytes Sagiaria, Typha and Colocasia may for the high oxygen consumption at Petit Saut was the amount of become established along the Downstream Channel, particularly organic maer that was inundated. At Petit Saut, the estimates for in the unlined section of the channel. the amount of organic mater inundated were 160 tonnes C/ha for In the Nam Theun below the Nakai Dam, under lower flow condi- the vegetation and 120 tonnes C/ha for the soil. Current estimates tions, pools may support a large phyto-plankton and filamentous on the amount of biomass to be inundated by the Nakai Reser- algal biomass. These pools may experience low dissolved oxygen voir are 40 tonnes C/ha and 70 tonnes C/ha for vegetation and soil concentrations in the early morning as a result of high nocturnal respectively (Hydreco, 2001a). respiration rates, leading to a net reduction in dissolved oxygen concentration and an increase in fish stress. Residence times of Results of Water Quality Analysis for the Nam Kathang & water in these pools should be between one to two days, based the Xe Bang Fai upon the depth and width of the pools and the length of the river The basic calculations of the water quality model consisted of between the dam and the junction of the Nam Phao. This residence determining the longitudinal profiles of dissolved oxygen in the time in the stream channel could possibly reduce large fluctuations Nam Kathang and Xe Bang Fai. The months from December to in algal productivity and dissolved oxygen concentrations. The May were selected for the simulation since they correspond to impact of the Nakai Dam on flows and water quality in the Nam the dry season, when the Nakai Reservoir water quality will have Theun is to be included in a further study of the riparian release. more influence than in other months. The findings of the study will be incorporated into this analysis. A series of field measurements was obtained in April 2001 to cali- Predicted Water Quality Downstream from the brate the model. Dissolved oxygen concentrations were measured in the Nam Kathang and the Xe Bang Fai, as well as from the Nam Power Station & Impacts Leuk power station. The Nam Leuk data was specifically collected to obtain information regarding the intensity of the processes of Modelling & Assumptions oxygen consumption by methane and organic maer. Results of Water discharged from the Power Station will be retained in the the dissolved oxygen and temperature measurements in the two RegulatingPond,wherethemajorityoftheflowwillbetransferred rivers are presented in Figure 3.42. to the Xe Bang Fai via the 27 km-long Downstream Channel.Apor- The results of the modelling, using water quality predicted for tion of the water discharged from the Power Station, equal to its the Nakai Reservoir, and discharge through the turbines in the natural inflow into the Regulating Pond, will be diverted into the Romero et al. scenario, and the water quality observed at Petit Saut, NamKathang.Toevaluatethepotentialwaterqualityconditionsin indicate that there will be no critical dissolved oxygen content in 90 Water Quality EAMP Main Text the Nam Kathang. The predicted evolution of dissolved oxygen the engineering work specifies that air should not be drawn into in the Nam Kathang for both the CWR and Petit Saut scenarios is the water in the pressure tunnel. presented in Figure 3.43. For the Xe Bang Fai, several scenarios were analysed: i) scenario Pesticides A used the predicted water quality from the CWR model; ii) sce- Increased agricultural activities in the Xe Bang Fai may lead to ele- nario B adopted the water quality discharge from Petit Saut and vated uses of pesticides. Some synthetic chemicals can be toxic to assumed a clean, efficiently functioning aeration weir and self- fish and have the potential to bio-accumulate in fish tissue to levels purification in the downstream channel; iii) scenario C assumed that are harmful to the human consumer. the same as scenario B except with a clogged and inefficiently func- tioning aeration weir; and iv) since the estimated biomass in the Social Impacts of Water Quality Changes Nakai Reservoir is less than at Petit Saut, scenario D adopted beer Many of the communities in the Project area live in close proximity water quality, with approximately halfthe methanecontentofPetit to the existing water bodies and currently utilise surface water and Saut (scenario B and C). Analysis results from these four scenarios groundwater for a variety of beneficial uses, including drinking are presented in Figure 3.44. water, recreation, washing, irrigation, fishing, and watering live- For CWR scenario A, no critical values of dissolved oxygen were stock. Therefore the quality of water is regarded as an important generated for the Xe Bang Fai. Equally, no critical values were issue, not only for aquatic life but also for the multi-use of water generated for the Petit Saut scenario B with a clean and efficiently by riverine and future reservoir residents. Any of the negative functioning aeration weir. However, for the Petit Saut scenario C, changes in water quality highlighted in the analysis above could with a clogged and inefficient aeration weir, the model predicts impact these beneficial uses of water, and therefore the communi- that the dissolved oxygen in the Xe Bang Fai would be 2 mg/l for ties themselves. (This is discussed in the SDP). a substantial portion of its length. Such a low concentration of dis- solved oxygen would be detrimental to fish populations. As indi- Mitigation of Potential Water Quality Impacts cated above, it is unlikely that the water from the Nakai Reservoir will be of similar quality to the reservoir of Petit Saut, because of To prevent adverse water quality conditions in the riparian release its much lower biomass. Therefore a higher concentration of dis- downstream of the Nakai Dam, the water for the riparian release solved oxygen and a lower concentration of methane are expected. will be drawn from the epilimnion and the discharge will be made Impacts Scenario D would not result in any critical values in dissolved oxy- through an aeration structure, a cone valve, that will spray water gen, with a minimum of approximately 4 mg/l. to the downstream reach. This will effectively aerate the water Assuming the aeration weir is maintained and working efficiently, and help fish populations to survive in pools downstream from the dissolved oxygen concentrations in the Xe Bang Fai should lie the Nakai Dam, should the water be of poor quality. The Romero somewherebetweenscenarioBandtheCWRscenarioA,presented et al. (2000) model predictions are that the quality of water enter- in Figure 3.45.Aclean aeration weir seems critical for the dissolved ing the aeration device for the riparian release and for dam spills oxygen in the Xe Bang Fai. Access for such cleaning would be pos- should generally be good, having low organic loads and moder- sible during the periodic low discharge on Sundays. ate to high dissolved oxygen concentrations. To alleviate impacts from the reduced flow, the analysis of riparian release and spills Other Factors will make recommendations on how the flow regime in the Nam Temperature Theun should be managed Aquatic weeds in the reservoir area, floating and submerged, can The colder water discharged from the Power Station will have a cooling effect on the Xe Bang Fai. This effect will be greatest in the be controlled through the annual seasonal drawdown and refill dry season, when there is less water in the Xe Bang Fai to buffer cycle. The shallow basin should prevent floating aquatics from the incoming Power Station discharge. In April, the power station moving into the minimum operating areas and most of the plants discharge temperature is estimated to be 26° C, which compares to an average of 31° C in the Xe Bang Fai. The warming process on the Power Station discharge in the Regulating Pond, and during its transition along the 27 km-long Downstream Channel, (which includes the aeration weir where the surface to volume ratio sig- nificantly increases heat transfer), could increase the water tem- perature by 1° C. Because of this warming process and the mixing of waters from the Xe Bang Fai and the Downstream Channel, it is expected that in the dry season, the temperature difference will be less than 3.5° C in the middle Xe Bang Fai and a maximum of 3° C in the lower Xe Bang Fai. This will impact Xe Bang Fai fish populations. In the wet season, the differential will be less, and will be buffered by the equal or greater quantities of water in the Xe Bang Fai, along with lower water temperatures. Supersaturation The entrance to the intake structure will be constantly drown and without vortices. Under normal operation there should be no air/water interface in the pressure tunnel or turbines, and therefore no mixing of air and water under pressure should result. Super- saturation is not expected to be an issue for the water discharge Figure 3.42: Results of water quality measurement in the Nam Kathang and from the Power Station. Even under load rejection, the design of Xe Bang Fai Water Quality 91 EAMP Main Text will be le in the extensive mud flats as the reservoir is drawn down. To help improve water quality in the Nakai Reservoir in the initial years aer inundation, NTPC will encourage the removal of bio- mass from the inundation area prior to flooding through firewood collection and the salvage of timber. A survey of present biomass in the inundation area is currently being undertaken, based on the interpretation of a Landsat satellite image of the Nakai Plateau from March 2003. This exercise will update the biomass estimate in the area to be inundated. The results will be used to propose means for maximizing removal of biomass (timber and firewood) in high biomass areas of the Nakai Reservoir. The Head Contractor's compliance with the existing construction schedule will help improve water quality conditions in the reser- voir during the initial years. It is particularly important to avoid situations similar to that which occured at the Nam Leuk hydro- power project reservoir. There, inundation occurred before the transmission lines were installed and the reservoir remained full without any possible exchange of water, for a longer period than planned. Even aer cuing and burning biomass before inunda- tion, the Nam Leuk reservoir turned anaerobic, resulting in fish kills in the reservoir and downstream aer the start of power pro- duction. Romero et al. (2001) carried out modelling of various destratifica- tion and direct oxygenation systems for the Nakai Reservoir. It was concluded that: i) the bubble plume system would result in oxy- genated conditions and lower nutrient concentration in the boom waters, but would not be feasible given the energy inputs for a res- Impacts ervoir the size of the Project's; and ii) direct oxygenation of boom water would be prohibitively expensive. Experiences from other reservoirs indicate extensive costs. The installation cost of destrat- ifers in North Pine Reservoir in Australia was US$ 13.9/ha at FSL, and operation costs were US$ 2.3/ha/month. If these costs were extrapolated to the Nakai Reservoir, the installation costs would be more than US$ 5 million, and the operation cost would be US$ 1.2 million/year. Even a high fish yield of 45 kg/ha would not then offset the costs of aeration and destratification. The intake structure for the Power Station is designed to draw water from the majority of the water column. The water discharge from the Power Station will therefore not consist only of poten- tially anoxic hypolimnion but also oxygenated epilimnion. Atech- nical drawing indicative of the intake structure is presented in Annex D. Toimprovethedissolvedoxygenconcentrationsinreleasedwaters from the Power Station, re-aeration of these waters will be pro- vided. This will be done by the discharge gates and structure at the regulating dam and the aeration weir located in the Downstream- Channel. The U-shaped structure will cause water to flow over the topofthebroad-crestedweirandfallintothechanneldownstream. The drop will be anywhere between 1.5 to 5.4 m depending on the discharge from the Power Station. This compares to the 1m drop of the Nam Leuk aeration weir. The Downstream Channel aeration weir will incorporate a specially designed nape with grids placed in a horizontal plane, designed to induce rainfall-type flow, and thus significantly increase the surface to volume ratio (Figure 2.13). This will enable entrainment of air into the water column and will be designed to increase the dissolved oxygen concentrations and reduce the methane and hydrogen sulphide concentrations. To protect water quality in the Nam Kathang two aeration struc- tures will be incorporated into the design of the Regulating Dam. The release structure of the Regulating Dam will include a hydrau- Figure 3.43: Predicted evolution of dissolved oxygen in the Nam Kathang lic jump and a weir is to be constructed at the end of the stilling for both the CWR (top) scenario A and the Petit Saut (bottom) scenario B basin. Both these additional structures will increase turbulence, for the month of April facilitating oxygenation and degasification of the water. 92 Water Quality EAMP Main Text Figure 3.44: The evolution of dissolved oxygen in the Xe Bang Fai for vari- ous CWR and Petit Saut scenarios Analysis of 1:30 scale models of both the Downstream Channel and Nam Kathang aeration structures concluded that the increase in the air/water interface and the aeration of water was effective over a range of flows (EDF 2002a and 2002b; LHM 2004). LHM (2004)concludedthatforoptimumaeration,thewater/airexchange surfaces must be maximized and therefore bubbles should be as numerous and remain as long as possible under the water before Impacts rising to the surface. In order to improve the weir's efficiency, the bubble formation zone had to be transferred away from the over- flowing nape in order to minimize disturbance. To achieve this, spliers were incorporated into the design to increase traversal velocities relative to horizontal velocities. In addition, during hydraulic testing, the weir's downstream portion was raised to achieve the target objective of uniformity of spilling over the entire nape. This recommendation has also been incorporated into the design of the aeration weir. LHM (2004) modeling also concluded that sediment deposits in the aeration wier have no influence on the overflowing nape. Technical drawings of these aeration struc- tures are presented in Annex D. The efficiency of the downstream channel aeration weir has been indicated to be around 70%. These efficiency forecasts are based on visualization of existing similar structures (weir and boom out- let gates at Petit Saut) (Alain Gregoire, pers. comm.). Past experi- ences of the effectiveness of similar aeration weir designs include: i) Canyon Dam, with a 68% oxygenation efficiency; and ii) South Holston, with a 60% oxygenation efficiency. The efficiency of the Downstream Channel aeration weir is based on a clean and functioning nape. Any bacterial or algal build up in the holes of the nape will lower its efficiency. Adequate access to clean the aeration weir's nape will be available during the periodic low discharge on Sundays. Monitoring To asses whether the Project is fulfilling its commitment, NTPC, under its contractual arrangements with GOL, will provide ade- quate monitoring of water quality in all water bodies concerned. Terms of Reference for the Water Quality Monitoring & Assessment Programme A Water Quality Monitoring and Assessment Programme (WQMAP) commenced early in 2005. The following section out- lines its aims, methodologies and expected outputs. Aims & Objectives of the Programme Figure 3.45: Predicted evolution of dissolved oxygen in the Xe Bang Fai for The overall aims of the Programme are to: i) achieve effective col- both the CWR (top) scanario A and the Petit Saut (bottom) scenario B for lection, analysis, interpretation and presentation of water qual- the month of April Water Quality 93 EAMP Main Text Impacts Figure 3.46: Section showing water level drawdown over long section from Intake to Dam Site ity data for surface water and groundwater in the Project area; · Develop a database for long-term storage and acquisition of ii) monitor whether NTPC is fulfilling its obligations stated in the water quality data; and Concession Agreement; and iii) assist in the formulation of appro- · Develop means to coordinate WQMAP with other ongoing priate mitigation measures and adaptive management strategies to and future monitoring programmes. help reduce the impact of any deterioration in water quality that may result from Project activities. 3. Mitigation Measures and Evaluation: The main objectives of the Programme are as follows: · Evaluate and recommend appropriate management and miti- gation measures that could be implemented to prevent/nullify 1. Development of the WQMAP: any adverse changes in water quality from pre-existing condi- · Develop a WQMAP that provide adequate information on the tions; and pre-construction, preliminary construction, construction and · Identify measures which may improve the WQMAP through operation phase groundwater and surface water quality; ongoing evaluation during the implementation phase. · Evaluate potential impacts resulting from construction and Approach & Methodology operational activities, with tailoring of the WQMAP to moni- tor for these potential impacts; United Analyst and Engineering Co. Ltd (UAE) are currently · Develop a Standard Operating Procedures Manual for sam- undertaking the WQMAP in close collaboration with the Lao pling, preserving and analysing surface water and groundwa- counterpart, Department of Irrigation (Dol) Analytical Chemis- ter; and try Laboritory. As such, a core component of the WQMAP is to · Provide training and technical support to the Lao agency con- provide sufficient training and technical support to strengthen the ducting the collection and analysis of samples. capacity of the Dol laboritory with a view to continuing involve- ment in this long -term monitoring programme. 2. Data Collection and Reporting: · Initially focus investigations on baseline data acquisition in Standard Operating Procedures Manual the pre-construction phase of the Project, then on the extent A Standard Operating Procedures (SOP) Manual with detailed of water quality change in the preliminary construction, con- stepwise instruction on how to conduct the WQMAPhas been pro- struction and operation phases; duced and updated as required: This manual utilizes well defined · Assess water quality, identify variations, trends and abnormal and widely used methodologies. All relevant stages and proce- levels, and investigate cases where trigger levels are exceeded; dures are detailed in the SOPManual, such as: i) sample collection; · Develop a coherent reporting system; ii) sample identification; iii) preservation techniques; iv) analytical 94 Water Quality EAMP Main Text techniques for each parameter; v) data management; and vi) QA/ Additional Parameter Requirements QC procedures. Pesticides & Other Synthetic Chemicals Parameters & Frequency for Surface Water Pesticides, herbicides and other synthetic chemical use in the The parameters given in Table 3.46 are initially included proposed Project area is expected to be minimal and their use is to be control- for monitoring surface water. A periodic review of this suite of led under the Pest Management Plan and the HCCEMMP. Hence parameters will be made and recommendations provided on the monitoring for such complex compounds and their residuals will initially not be undertaken. If it emerges that such chemicals are requirement for additional parameters. beingutilisedforProjectactivities,thenconsiderationwillbegiven The majority of the parameters for surface water will be monitored to monitoring for those specific compounds in use. with some indicating parameters (pH, conductivity, turbidity, etc.) Petrochemicals being monitored on a weekly basis. A review of the sampling fre- Petrochemicaluseandspillageduringconstructionistobecontrol- quency will assess whether data has statistical rigour and is ade- led by environmental measures to be outlined in the HCCEMMP. quate to answer the tasks set out in the objectives. If a major spill event occurs, then monitoring for such compounds Parameters & Frequency for Groundwater will also be required. Parameters presented in Table 3.47 are initially included for moni- Heavy Metals in Fish Tissue toring groundwater. Monitoring of these parameters is required Asaresultofthepotentialformercury,arsenicandleadtobioaccu- under GOL Resolution No. 953/MOH on water quality targets for mulateinfishtissuetolevelsthatcouldbeharmfultopublichealth, the WQMAPwill include the possiblelity to monitor for these met- rural water supply systems. alsinfishtissue.Procedureswillbedevelopedtotakeintoaccount: Thesamplingfrequencyproposedformonitoringexistingground- i) site selection; ii) timing of sampling; iii) target species and size water supply will be on a twice per year basis, at the end of the wet to be sampled; iv) type and number of samples per species; v) field season (November) and at the end of the dry season (May). handling procedures; vi) laboratory analytical procedures; and vii) Impacts trigger level procedures. Any domestic water supply systems established for communities as part of the Project's compensation package, or established for Biological Monitoring personnel associated with the Project, will require an initial assess- Given the inherent temporal and spatial dynamic of monitoring ment to ascertain whether the Project is supplying water of ade- aquatic ecosystems using only physico-chemical parameters, the quate quality. Aer this, the domestic water supply will be sam- WQMAP will be integrated with a biological monitoring pro- pled on a biannual basis. A review of the sampling frequency for gramme. The monitoring of several trophic levels: i) phytoplank- ton; ii) benthic macro-invertebrates; and iii) fish, will provide a groundwater will be carried out and recommendations provided if clearer understanding of any adverse water quality impacts that any adjustment to the sampling frequency is required. may develop, and provide an early warning system to monitor any proliferation of certain species of algae which can be toxic to both livestock and humans. Table 3.46: Proposed suite of parameters for surface water monitoring Surface Water Sampling Site Location Parameter Temperature The sampling site locations are presented in Figure 3.47. The loca- pH tions are chosen to enable assessment of water quality conditions Total Suspended Solids in the Nam Theun both upstream and downstream of the pro- Nitrate (NO3) - posed Nakai Dam and in the Nam Kathang/Nam Gnom, Nam Phit Calcium (Ca2 ) + and Xe Bang Fai. additional sampling sites might be required dur- Silica ing the main construction phase as the location of work camps and Total Iron construction sites are finalised and construction starts. Sampling Lead site locations for the Nakai Reservoir will be finalised aer inunda- Fecal Coliforms tion Dissolved Oxygen Conductivity Alkalinity Table 3.47: Suite of parameters proposed for groundwater monitoring Nitrite (NO2) - Parameter Total Phosphorus (TP) Potassium (K+) Conductivity Magnesium (Mg2 ) + Nitrate Mercury Iron Biological Oxygen Demand (BOD) Number of thermo-tolerant Coliforms Climatic conditions pH Turbidity Manganese Ammonia (NH4 ) + Odour Sodium (Na+) Total Hardness Manganese (Mn2 ) + Turbidity Arsenic Fluoride Chemical Oxygen Demand (COD) Arsenic Water Quality 95 EAMP Main Text Groundwater Sampling Site Location Reporting of Hazardous Levels The initial goal of groundwater monitoring is to collect indicative NTPCwillbeimmediatelynotifiedofanyhazardouslevelsaained baseline data for representative regions of the Project area. The or when a trigger level for a parameter has been exceeded. When number and location of the groundwater sampling sites is to be the trigger level is reached, the course of appropriate action will proposed once an assessment of domestic water supply system be assessed on a case-by-case basis. The results of analysis for sur- types, numbers and locations is carried out to facilitate the deci- face water shall also be compared to agreed-upon and recognised sion. In addition, any installation of domestic water supply sys- standards. NTPC will also be immediately notified if groundwater tems associated with the Project will require monitoring. parameter values exceed any one of the standards set by the GOL in resolution No. 953/MOH (14 July, 2003). The target values for Outputs rural water supply systems are presented in Table 3.48. Monthly Reports Values in excess of the Lao standard shall be regarded as a trig- ger for further investigation, including a major ion analysis. The A monthly report shall be submied during the course of the results of analysis should be compared to agreed-upon and recog- project which summarises all water quality data, including: i) nised standards for groundwater. parameters measured; ii) specific sample site locations, sampling dates and time of collection; iii) description of methodologies Water Quality Database and any deviations from the agreed methodology; iv) values for Adata management system is being developed and maintained for parameter mean, range, standard deviation and variance; v) inter- effective storage and retrieval of data. pretation of the data in terms of trend analysis and/or diagnosis of problematic levels; vi) recommendations to alleviate problematic Evaluation & Monitoring levels. Periodic review of sampling techniques, site selection, analytical Inter-Programme Cooperation techniques and other elements will be carried out of to assess the effectiveness of the WQMAP and to check whether it is success- Inter-programme cooperation with other relevant programmes fully addressing its specific objectives. Continual evaluation of might be required. WQMAP reports will serve primarily as an methodologies and data outputs shall be made and recommenda- assessment of water quality, but also to facilitate the development tions given. and management decisions for other programmes, such as the Res- ervoir Fisheries Management Plan. Aquatic Habitats & Fish Diversity Impacts Despite the high diversity of fish in mainland Southeast Asia, with some 900 species known (Koelat, 1989), and their impor- tance for humans as a source of protein, knowledge of fish biology over most of Asia is very incomplete and oen limited to lists of species (Koelat & Whien, 1996, Koelat, 1990). Lao PDR is no exception. A synopsis for the whole of Lao PDR recorded 203 spe- cies in 1974 (Taki, 1974). The list had grown to 481 species by 2001 (Koelat, 2001) aer five exploratory surveys. Even with Koe- lat's significant contribution to the increase in knowledge of fish distribution in Lao PDR since 1996, information on fish distribu- tion, biology and ecology remains basic, making it sometimes dif- ficult or impossible to prepare a proper and detailed assessment of impacts. In addition, data on fish distribution in Mekong River tributaries in Lao PDR and in the region is still insufficient to allow a comprehensive zoogeographic review. It will take years of surveys before a beer knowledge is acquired (Koelat, pers. com.). Ichthyological explorations of the Nam Theun, Xe Bang Fai and tributaries by Koelat were the first ever to occur (Koelat, 1996). Before these missions, no reliable data on fish distribution and biology was available for the Nam Theun and Xe Bang Fai basins. Surveys have targeted the main types of habitats found in these rivers: rapids, riffles, waterfalls, river confluences, pools (to some extent), slow water stretches of rivers, forest streams in their upper, middle and lower sections of the rivers and swamps on the Nakai Plateau. Stations surveyed are represented in Figure 3.48. This section is based on the work done by Dr. Koelat from 1996 to 2003 (Koelat, 1996, 1997, 1998, 2000, 2001, 2002, 2003). Fish Habitats The main types of habitats in the Nam Theun and the Xe Bang Fai are briefly described in this section. Species of fish presently recorded in the Nam Theun and Xe Bang Fai basins are presented in detail in Annex K. During the dry season, the types of habitats that are available to fish populations include waterfalls, rapids, rif- fles, forest streams, pools, underground water, swamps and stag- Figure 3.47: Water quality sampling sites proposed for surface water nant pools. During the wet season, most of these habitats change 96 Water Quality EAMP Main Text Table 3.48: Lao PDR water quality targets for rural drinking water Parameter Unit Lao WQ Target for Rural Drinking Water1 Conductivity µS/cm 1,000 pH pH 6.5-8.5 Turbidity NTU < 10 Nitrate mg/l 40 Manganese mg/l < 0.5 Fluoride mg/l < 1.5 Iron mg/l < 1 Taste & odour n/a Acceptable Arsenic mg/l < 0.05 Thermo-tolerant coliforms number/100 ml 0 Total hardness mg Ca/l < 500 Notes: 1: Taken from Resolution No. 953/MOH (14th July 2003) completely and some are displaced to other areas. Fish popula- tions frequently use habitats that are not available during the dry Figure 3.48: Fish distribution survey sampling site locations (Project Area season for spawning, incubation of eggs, and rearing of fry. In the & Surrounds) Nam Theun and Xe Bang Fai basins, habitats that are important to fish populations include riverbank terraces and floodplains, The Nakai Plateau including the flood plains at the confluence of the Xe Bang Fai Impacts with the Mekong River. Flooded areas serve as nursery grounds The Nam Theun meanders over the plateau in a succession of rela- and refuges for juvenile fish. Some habitats are underrepresented tively slow runs, rapids and deep pools. The substrate varies from sand (especially at the mouth of tributaries, e.g. Nam Xot, Nam in the surveys. The fish from the deep pools (up to 44 m upriver On) to rocks. The water is relatively clear. The fish fauna can be of the dam site) of the Nam Theun main stream were obtained by classified as a somewhat depauperate version of the middle and fishermen using gill nets, and hook & line. It is possible that other upper Nam Theun, where the species specialised for the fastest species occur only in such habitats, which were not surveyed with waters are missing. Extensive areas are flooded in the wet season ichthyocides aer consideration of the volume of waters and the and some more or less perennial swamps exist. Those surveyed quantity of chemicals required, the potential important quantity are inhabited by few species, all widely distributed in the Mekong of fish that would be killed by this operation, and the proximity of basin. human communities. Headwaters of the Nam Theun Basin Lower Nam Theun Basin The surveyed headwaters (Nam Phao, Nam Xot and Upper Nam The river section (as defined here) extends from Ban Katok to the Theun) are all on relatively steep slopes, and consist of successions confluence with the Nam Gnouang (and is inclusive of the Theun- of waterfalls, rapids, riffles and fast runs over stony to rocky sub- Hinboun headpond and dam).The river is wide, in a relatively strate, occasionally with sand banks. The water is very clear, except open landscape. It flows over a muddy to sandy substrate with in the upper Nam Phao, where it is contaminated with agriculture several sets of rapids. A few kilometres downstream, the Nam and organic waste from Ban Lak Sao. The fish fauna mostly con- Kading enters gorges. The fish fauna consists of a mixture of a dep- sists of species specialised for these very fast waters, many of them auperate (in terms of species number) version of the fauna of the previously known only from the Mekong basin in Yunnan. middle section of Mekong tributaries combined with species of the upper sector. Middle Nam Theun Basin This sector is a succession of rapids and runs in the gorges extend- ing between the lower Nam Theun (around Ban Katok) and upstream of the Nakai Dam. The fauna is not very diverse but con- sists of species specialised for this habitat. The river-reach between the confluence of the Nam Phao with the Nam Theun and the loca- tion of the proposed Nakai Dam is nearly 12 km long. During the dry season it includes four large and three small rapids areas. The pools are at least 50 m wide and 1 km long and one pool is 4.2 km long and 150 m wide. Through this reach the river gradient is high, averaging 3.33 m per km. As a consequence, the water velocity is relatively high. The river reach has four sandbars. For the most part, substrates in the reach are primarily rock and rock outcrops with large boulders. The water surface consists of about four hec- tares of rapids and 124 ha of pools and runs. Plate 5: Rapids on the lower Nam Theun near Ban Katok (Kottelat) Aquatic Habitats & Fish Diversity 97 EAMP Main Text Plate 6: Waterfall and rapids in the middle Nam Theun, upstream of the Plate 8: Nam Theun upstream of Ban Thalang, on the Nakai Plateau confluence with the Nam Phao (Kottelat) (Kottelat) Lower Xe Bang Fai Basin Upper Xe Bang Fai Basin The lower Xe Bang Fai, which runs from its mouth upstream to the Upstream of its underground course, the Xe Bang Fai flows mostly confluence with the Xe Noy, is characterised by a muddy to sandy over a succession of rapids, riffles and runs in a karstic landscape: boom, with occasional rocky outcrops and rapids. The water is 6 km of its course are in a natural tunnel. The water is very clear (visibilitywasatleasttwometresattheentranceofthetunnel).The turbid, although compared to most other lowland streams in the fish fauna is in part a subset of the middle Xe Bang Fai fauna spe- Mekong basin it is still clear, with a visibility of about 50 cm. The cialised for faster waters, and with some species otherwise known Impacts depth is variable, from several metres to a few centimetres on some only from the Nam Theun and from tributaries of the Mekong in sandbars. The fish fauna is similar to other flood-plain rivers in the Yunnan. middle Mekong basin. Fish Diversity & Endemicity Middle Xe Bang Fai Basin ThefishesoftheNamTheunandXeBangFaibasinshavebeensur- The middle Xe Bang Fai extends from the confluence of the Xe veyed at 42 sites in 1996, at 25 sites in 2002 and 16 sites in 2003 (Kot- telat, 1996, 1998, 2002, 2004). One hundred and thirty-one species Noy upstream to the outlet of its underwater course, some 117 km have been observed in the Xe Bang Fai and 68 in the Nam Theun upstream of Mahaxai. It flows in a succession of runs, riffles and (Annex K). Eleven species (18%) of the Nam Theun fishes and five occasional rapids and deep pools. The substrate is sand to rocks. (4%) of the Xe Bang Fai fishes were known from nowhere else at The water of the mainstream is unusually clear for a river of this the time of the first survey in 1996. As similar data was missing size in the lowlands. The fish fauna is shared with other similar for other river basins, additional surveys were necessary to decide habitats in tributaries of the Mekong, with a few additional spe- whether this apparent endemism was real or not. In 1997, several other basins of Lao PDR (Nam Xuang, Nam Ou, Nam Beng, Nam cies inhabiting the rapids and riffles. Small tributaries, such as the Tha, Nam Youan) were surveyed in order to identify which species Nam Phit, are characterised by very sluggish or standing waters, wereendemictotheNamTheunandXeBangFaibasinsandwhich usually very turbid, and are inhabited by species that prefer slow were not (Koelat, 1997). Figures 3.49 and 3.50 illustrate the sam- moving water. pling site locations of these additional surveys. The 1997 survey concluded that two species (Schistura punctifasciata, Terateleostris aspro) were considered as endemic to the Xe Bang Fai basin, with their distribution range including or restricted to areas upstream of the direct impacts of the Project. While they could exist in other basins they have not to date been collected. The failure to collect the species from other basins may be a function of the rareness of Plate 7: Sandbar at the confluence with the Nam Phao (Kottelat) Plate 9: Swamps on the Nakai Plateau, east of Ban Boua Kham (Kottelat) 98 Aquatic Habitats & Fish Diversity EAMP Main Text Plate 10: Waterfall in the headwaters of the Nam Theun (Kottelat) Plate 11: Rocky Stream in the headwaters of the Nam Theun (Kottelat) the species, its narrow habitat requirements, or may be a result of Scaphognathops theunensis is not restricted to Project area but also a limited sampling effort in other basins. Within the Xe Bang Fai, includes the middle Nam Gnouang and the Nam Kading. Until Terateleostris aspro was collected from a single locality in an area 2003, Tor ater was definitively known only from three specimens that will not be affected by the diversion of water to the Xe Bang said to have been collected on the Nakai Plateau. Another survey Fai. In 2002, Schistura punctifasciata was also collected from a loca- in May 2003 by Koelat, found Tor ater in sections of the Nam Xot tion upstream from the confluence of the Nam Phit that will not and the upper Nam Theun that will be unaffected by the Project. be impacted by the increased discharge to the Xe Bang Fai. The Observations and interviews with villagers suggest that Tor ater is Impacts 1997 survey also concluded that from the 12 species considered present in the upper reaches of the Nam Theun and its tributaries. as endemic to the Nam Theun ­ Nam Gnouang basin, eight had a In that area, it inhabits deep pools in stretches with a higher gradi- small to significant part of their known distribution range outside ent. Tor ater is absent from stretches with low gradients (e.g the the area that will be directly impacted by the Project. One endemic Nakai Plateau) and does not undertake long distance migrations. species(Banganaelegans)wasknowntobemigratory,buttheextent of its migrations is still not known. The species lives in the upper The fish is expected to be able to complete its entire life cycle in Nam Theun and Nam Xot. Juveniles have also been found in the these sections (Koelat 2004). Therefore all the species currently Nam Phao basin, indicating the species spawned there in 2002. In known to be present in the Nam Theun and Xe Bang Fai exist 2003, individuals of the whole known size range were observed in either in other basins or outside the area of direct Project impact. theupperNamXotandNamTheun,abovetheFSLofthereservoir. The diversity of fish in the Nam Theun is low compared with the Three species had their whole known distribution in areas which Mekong mainstream (Taki, 1974, Koelat, 1989, Roberts, 1995) and will be directly impacted by the Project and the Theun Hinboun the adjacent Xe Bang Fai basin. The fish fauna in the Xe Bang Fai project, and their survival was uncertain: Scaphognathops theunen- basinincludesatleast131speciesoffish­thatisconsiderablymore sis, Schistura cataracta, and Pseudecheneis sympelvicus. Since 1997 species than the Nam Kading/Nam Theun basin where 68 species the laer two species have been observed elsewhere in Lao PDR havebeenidentified(Koelat,2002).Sixty-seven(67)ofthe131fish (including the Nam Phao, the Nam Ngum and the Nam Ngiep), species in the Xe Bang Fai were collected from the Lower Xe Bang but an additional species, Tor ater, was reported as endemic to the Fai, while 96 species were found in the Middle Xe Bang Fai. Based Nakai Plateau. In March 2002, parts of the Nam Gnouang and Xe on the results of these surveys, the fish communities in the Nam Bang Fai basins were surveyed in order to assess the possible pres- Kading and Nam Theun are not comparable to the fish diversity in ence of Scaphognathops theunensis and Tor ater outside of Project the Xe Bang Fai. Major differences between the two rivers, such as area. The survey was successful in showing that the distribution of topography, habitats, zoogeography explain the disparity: habitats Plate 12: Rapids in the headwaters of the Nam Theun (Kottelat) Plate 13: The lower Xe Bang Fai, near its mouth (Kottelat) Aquatic Habitats & Fish Diversity 99 EAMP Main Text Plate 14: Middle Xe Bang Fai ­ exit of the underground course (Kottelat) Plate 15: Upper Xe Bang Fai near Phou Taloun (Kottelat) in the Xe Bang Fai are more diverse and the river has direct com- Faunistic Affinities munication with the rich Mekong fauna. In comparison, the Nam While the lower and middle Xe Bang Fai fauna can clearly be Theun has a rheophilic fauna, closer to the one of Yunnan and its described as a middle Mekong fauna, the Nam Theun and the high level of endemism, than to the Mekong fauna. upper Xe Bang Fai fish fauna is very distinctive from what is Mitigation: The populations of critical species shall be monitored known about the rest of the middle Mekong basin, and it shows in order to detect possible declining populations and to help pro- obvious affinities with Yunnan fish fauna. Several species reported vide recommendations for appropriate support measures (e.g. by Koelat were previously known from the Mekong basin in Yunnan (Folifer brevifilis, Garra theunensis, Hemiculterella macrolepis, restriction or ban of captures, establishment and use of captive Luciocyprinus striolatus, Onychostoma fusiforme, Poropuntius carina- Impacts stock for stocking and supporting wild population, increasing tus, Tor lateriviatus, Balitora lancangjiangensis, Homaloptera yunnan- areas of protected pools). For rivers in the NNT NBCA, sustainable ensis, Schistura dorsizona, Glyptothorax macromaculatus, G. zainaensis, management programs will be established under the SEMFOPthat Oryzias sinensis). Hemimyzon papilio and Pseudecheneis sympelvi- will benefit biodiversity conservation. cus are closely related to species known from the Mekong basin in Yunnan. Oreoglanis hypsiurus is closely related to species from northern Lao PDR and Yunnan. Botia nigrolineata and Rasbora atri- dorsalis from the Xe Bang Fai were previously known only from Xishuangbanna (Yunnan). Most of these species have since been found in other basins in northern Lao PDR(Koelat, 1997), making a continuity of distribution from Yunnan to the Nam Theun basin. They do not occur in the Mekong basin in northern Thailand, pos- sibly because of a lack of suitable habitats. Misgurnus anguillicau- datus, Rhodeus laoensis and Hemibarbus cf. umbrifer occur in or have affinities with species from Vietnam. The Nam Theun fish fauna consists mainly of species specialised for hill streams and fast flowing waters; these waters are usually cooler and have higher oxygen content than lowland streams. Restricted distribution to headwaters may result from the absence Figure 3.49: Catchment area of additional fish distribution surveys (Houa- Figure 3.50: Catchment area of additional fish distribution surveys (Savan- pahn & Xieng Khouang Provinces, Lao PDR) nakhet Province, Lao PDR) 100 Aquatic Habitats & Fish Diversity EAMP Main Text Plate 16: Luciocyprinus striolatus Cui & Cui, 1986. Found in the Lower Nam Theun. of morphologically suitable habitats downstream (some species may be unable to feed and reproduce in the lowland habitats), from the inability to survive at the temperature and oxygen con- centrations in the lowlands, or a combination of both. Koelat (1996) is of the opinion that there are no significant affinities with the Vietnamese fish fauna and one of the three species (Misgur- nus anguillicaudatus) belonging to the Vietnamese fish fauna might have been introduced in the rice fields near Ban Lak Sao. Fish Populations Impacts Koelat (1996) sampled different fish habitats in the Nam Theun and the Nam Kading to develop an estimate of the standing stock of fish in the basins during the dry season. As shown in Table 3.34, the highest standing stocks of fish are located at waterfalls and Plate 18: Juvenile (top) and adult (bottom) Tor ater Roberts, 1999. Found rapids, where high oxygen concentration, good light penetration in the Upper Nam Theun. and the rocky substrate allow an algae growth on which a variety of fish and invertebrates feed. The fish standing stock is lowest in habitats where the primary production is very low. the study is to quantitatively establish an index of the current fish resource in the section of the Xe Bang Fai to be impacted. The basis Koelat sampled three locations with seines to obtain informa- of the data is catch per unit effort (CPUE), which is commonly tion regarding the standing stock of fish in the Xe Bang Fai. He used throughout the world to monitor temporal trends in fish estimated that the standing stock in the Lower Xe Bang Fai was abundance, including Lao PDR (Warren, 1998, Noraseng and War- between 6 and 23 kg per hectare (Koelat, 1996). This number ren, 1999). The CPUE provides a relative index of fish abundance. of fish is considerably less than what was expected considering higher nutrient concentrations. This could be the result of fishing In total, seven villages are involved in the study. These villages activities by local fishermen and because samples were taken dur- are located along the entire length of the Xe Bang Fai between the ing the dry season when few fish from the Mekong were in the confluence of the downstream channel and the confluence of the river to spawn. Mekong (Figure 3.51). To collect the quantitative CPUE data three "skilled" fishers were selected from each village to record their Xe Bang Fai Baseline Fisheries Resource Survey dailycatchdatafromgillnetsonceperweek.Resultsfromtwoyears of sampling are presented in Table 3.49 (Warren, 2003, 2004). The LARREC and Warren, commissioned by NTPC, are undertaking results for fish species caught by fixed gillnets indicate that there a pre-operations baseline study of the aquatic resources in the are substantial differences in overall abundance between years Xe Bang Fai. This investigation began in 2001 and will continue and to some extent between locations on river stretches. Abun- until sufficient baseline data has been obtained. The objective of dance was lowest at Dan Pakse at the confluence with the Mekong. Monthly variations in abundance along the river channel reflect seasonal migratory behaviour of fish. Most of the catch consists of medium size cyprinids (Puntioplites spp, Hypsibarbus spp, Barbodes spp, Labeo chrysophekadion, Puntius orphoides). Catfishes (Pangasius siamensis, Clarias batrachus, Mystus wyckioides, Hemibagrus nemurus) and snakehead (Channa striata) are less important. Following COD the study will continue and is designed to establish if the operation of the Project will increase or decrease the availability and "catch- ability" of fish for use by the communities along the Xe Bang Fai. Migrations Three geographically-defined fish migration systems are thought to exist in the Mekong Basin: lower, middle and upper Mekong migrationsystems(Poulsenetal,2000,2002,2004).TheNamTheun Plate 17: Scaphognathops theunensis Kottelat, 1998. Found in the Lower and Xe Bang Fai basins fall within the middle Mekong migration and Middle Nam Theun, and on the Plateau. system. Within this river section floodplain spawning and nursery Aquatic Habitats & Fish Diversity 101 EAMP Main Text habitats are associated with the tributaries. Adults and juveniles migratory paerns are being collected with the long term LARREC spend the dry season in deep refuge pools in the mainstream chan- and Warren study of the Xe Bang Fai. nel. At the onset of the wet season, they migrate upstream along Fishes are harvested at different intensities in the different rivers the Mekong until they encounter a tributary, and then swim up the either as a source of protein or for sale in local markets. Fishing tributary until they encounter floodplain habitat or other possibly suitable spawning habitat. Many species spawn only once, soon gear and equipment reported from the Nam Kading/Nam Theun aer arriving on the floodplain, while others spawn several times and the Xe Bang Fai basins include explosives, poisonous plants, during the flood season, and a few others spawn only once at end nylon monofilament gill nets, spears, hook and line, cast nets, of the wet season or beginning of the dry season. The fry grow out scoop nets and many types of trap. Warren (2001) suggests that on the floodplain which acts as a nursery and contains rich forage. dri and fixed gillnets are the most important gear in terms of the As the flood water begins to recede from the floodplain, adults and size of fish landings made by fisherman from the Xe Bang Fai. The juveniles migrate back in the tributaries and move downstream to presence of only juvenile fish at some locations in the Nam Theun the Mekong. There are over thirty medium and large size species indicates locally intense fishing activity (Koelat, 1996). of cyprinid and pangasiid catfish which exhibit this general migra- Various surveys (GOL, 2001, Shoemaker et al., 2001) reveal the tion paern. importance of fisheries to the local economy. This is further dis- cussed in the SDP. The seasonal fish migrations between the Migration in the Nam Theun Mekong River and Xe Bang Fai are important components of the Various reports comment on upstream wet season migrations in economiclivelihoodsofvillagesontheXeBangFaiitselfandmany the Nam Theun (Norconsult, 1994; NIVA/NIN-NIKU, 1995; Kot- of its tributaries. telat, 1996; NORPLAN, 1996), but the knowledge base is fragmen- tary and incomplete. It is not clear if upstream migration is carried Fisheries out only by fish resident in the Nam Theun, or if it includes also Fishing effort in the Nam Theun below the Nakai dam is minor. migrating fish stocks entering from the Mekong. The difference in The main fishery in the Nam Theun is on the floodplain of the species diversity along the length of the Nam Theun suggests that Nakai Plateau. On the Plateau there are some 864 fishing house- one or more of the rapids (i.e. Keng Vang Fong) may constitute a holds (84% of all households). Almost all fishing is subsistence natural barrier to migration/dispersal for some fish species. Cer- (60% of catch is consumed), with some excess catch (40%) being tainly the Theun-Hinboun dam constitutes an additional impedi- sold. The main fishing gears are gillnets (targeting carps and cat- ment. It has been reported that fish up to 8 kg in size aempt to fishes such as Pangasius and bagrids), hook and line (targeting leap over the dam wall following the commencement of wet sea- Clarias, Pangasius, Mystus and Tor), traps (targeting snakeheads Impacts son. Species suspected of being longer distance migrants in the and eels), castnets (targeting small cyprinids and small floodplain Nam Theun basin include Bangana elegans and some Tor spp. resident species), linets, scoop nets, plunge baskets, harpoons Migration in the Xe Bang Fai and brushparks. Damming and fencing small creeks and hand col- The first major fish migration of the year commences at the begin- ning of the wet season. At that time, according to villagers, a large number of fish species begin migrating up the Xe Bang Fai, and its largertributaries,whileotherfishspeciesarebelievedtomovefrom deep-water pools to spawning areas in the Xe Bang Fai.According to Shoemaker (Shoemaker et al., 2001) together, these two migrat- ing groups include the following taxa: Cyprinids (Labeo chrysophek- adion, Labiobarbus sp., Sikukia gudgeri, Hypsibarbus sp., Puntioplites sp.), Catfish (Pangasius larnaudii, P. macronema, P. pleurotaenia, P. bocourti, Wallago au, W. leeri, Bagarius sp, Hemibagrus wyckioides, H. nemurus, Helicophagus waadersi, Laides sp., Mystus spp.), Mud perch (Pristiolepis fasciata), Glassfish (Parambassis siamensis), River loach (Schistura sp. or Nemacheilus sp.). During overbank flooding events fish migrate laterally to temporally inhabit adjacent flood plains for spawning and feeding. Migrations are a complex phenomenon involving dozens of species, each with its own migratory paern and different times of movement. Lile reliable data on fish migra- tions and reproduction in the Mekong basins is available (Tori, 1978, Koelat, 1996, Shoemaker, 2001). Elements of information on Table 3.49: Fish standing stock per habitat in the Nam Kading/Nam Theun basin Fish Standing Stock Number of Fish Species Fish Habitat Range Mean (kg/ha) (kg/ha) Range Mean Waterfall 927 927 11 11.0 Rapids 46 ­ 224 155 6 ­ 21 11.5 Riffles 78 ­ 129 100 12 ­ 15 13.6 Runs 46 ­ 117 81 8 ­ 9 8.5 Forest stream 40 40 14 14 Figure 3.51: Fisheries monitoring sites. 102 Aquatic Habitats & Fish Diversity EAMP Main Text lection are also practiced. Some fishermen have boats and engines Work in the Riverbed and range up to 10 km when fishing. Fishing takes place in the main river channels, and also in wetlands (targeting air breathing Construction of the coffer dams, the Nakai Dam and the Down- species such as Clarias, gouramies and snakeheads).Average house- stream Channel are activities that could potentially increase sedi- ment load. Fish living in clear water habitats are directly affected hold fish consumption is about 330 kg per year and total annual by increased suspended sediments that may damage their gills catch from the Nakai floodplain is estimated at about 285 t. Fish or accumulate in their gill chambers, leading to death. Indirect stocks on the Nakai plateau are considered significantly depleted effects include: i) silt deposition over rocky habitats; ii) destruction due to increasing fishing effort during the last decade. of spawning sites (some fish species may migrate to very precise The population of the mainstream Xe Bang Fai is some 40,601 per- spawninggroundsandmaynotbreediftheseareasbecomesilted); sons with an additional 3,356 fishers identified in the hinterlands iii) silt deposition over freshly laid eggs or newly hatched larvae; (SDP 2004). Some 67% of all households along the mainstream fish and iv) reduced primary production as a result of reduced light only for subsistence consumption, while the remainder sell part of penetration (affecting herbivorous fishes, fish preying on inverte- their catch (GOL, 2001). Fish constitutes the major source of animal brates that feed on algae, and fish that use algae as either a refuge protein. or spawning substrate). Fishing gear and equipment reported from the Nam Kading/Nam Mitigation: The works at the Nakai Dam site will expose the riv- Theun and the Xe Bang Fai basins include explosives, poisonous erbed. However a diversion tunnel associated with the two coffer plants, nylon monofilament gill nets, spears, hook and line, cast dams will create a shortcut in the course of the river during the nets, scoop nets and many types of trap. Warren (2001) suggests dry season, isolating the river from the main construction area. that dri and fixed gillnets are the most important gear in terms of As a consequence the dam construction should not result in an the size of fish landings made by fisherman from the Xe Bang Fai. increased sediment load in the river. The diversion tunnel will be Catch shows significant seasonal variation, and fishermen change completed before beginning any work in the riverbed. Standard their fishing gears to adapt to seasonal habitats and target spe- mitigation methods and limiting the construction of the diversion tunnel to the dry season should help limit the amount of sedimen- cies. The main Xe Bang Fai channel and some tributaries are the tation in the Nam Theun. Construction material, including mate- most important fishing ground during the dry season (when fish rial for the diversion works, will not be dumped in the river but Impacts congregate in refuge habitats such as waterfalls, rapids and deep transported to secure disposal areas, above the level of the rainy pools), while tributaries and habitats on floodplains (flooded for- season flows. Construc-tion sites will be cleared before they are ests, swamps, backyard ponds, paddy fields) are important during flooded. the wet season. The HC will adhere to the erosion plans set down in HCCEMMPs Catches consist mainly of cyprinids and catfishes, many of which to help limit sedimentation resulting from construction of the in-migrate from the Mekong mainstream. Catches in the flood- downstream channel. In the Xe Bang Fai, some species are adapted plains also include resident species such as snakehead, mud perch, to high loads of suspended solids, to which they are currently sub- spiny eels, climbing perch, walking catfish, and gouramies. Anec- jected to in the wet season. dotal information suggests that production has declined over the last 10-15 years. Average fish size and the number of species Infrastructure Construction caught have also declined. The reason for the decline is thought to Construction of infrastructure can affect the freshwater ecology be overfishing and use of small mesh monofilament gillnets. through increased sediment load (effects are as indicated above). Other than a number of trap ponds on the Nakai Plateau, there Impacts occur when: i) construction material is washed into the is no aquaculture activity in the Nam Theun basin. The level of water course; ii) unstabilised infrastructure is washed away in the aquaculture activity in the Xe Bang Fai is marginally higher, with rainy season; iii) small streams are dammed instead of bridged less than 3% of households involved. Backyard ponds, ricefield (this oen results in the creation of a reservoir of biologically dead fish culture, and village swamp fish culture are the most important water upstream of the weir and a dry stream bed downstream); types of fish culture. Net cages are least important. No production and iv) inappropriate bridges are constructed (e.g., partial dam- estimates are available for aquaculture activity in the Project area ming of the stream, pipes, extensive modification of the stream bed and banks). When temporary infrastructure or roads are con- Potential Impacts on Aquatic Habitats structed there is a greater potential for ii) and iii) to occur. Analysis of potential impacts is somewhat constrained by limited Mitigation: All infrastructure, including temporary constructions, information on fish distribution and biology, and no information will be stabilised and bridges will be built to respect the existing on the precise ecological requirement or the reactions to environ- stream/river bed and bank morphology. Construction material will mental stress of the fishes native to the surveyed area. The analysis be transported to disposal areas. Temporary roads will, as much presented here is derived from Dr Koelat's experience with other, as is possible, be built in the area to be flooded. Particular aen- related species in adjacent areas and expertise. Two main types of tion will be paid to the logging roads that will be necessary for clearing vegetation in the reservoir area, especially to those which impacts are presented: i) impacts related to the construction and may need to cross areas which will not be flooded. This action will ii) impacts related to the permanent changes to the various aquatic respect existing stream morphology. No streams (even temporary habitats. Mitigation measures are proposed whenever possible. ones) outside the flooded area will be dammed by road or infra- Construction Related Impacts structure construction. The possible impacts of the Project on aquatic habitats and bio- Water Pollution diversity during construction include: i) work in the riverbed; ii) Spills of fuel and chemicals may have direct and indirect impacts construction of Project infrastructure; iii) water pollution; iv) use on the aquatic fauna, as well as on humans and animals feeding on of explosives; v) vegetation clearing; and vi) limestone extraction aquatic products. Pollution most oen occurs where pollutants are in karstic formation. stored, but also when they are used incorrrectly. Aquatic Habitats & Fish Diversity 103 EAMP Main Text Mitigation: Retention tanks will be constructed around every area present, the opportunity to explore them scientifically should be whereliquidandsolidfuelsorchemicalsarestored.Emptypackag- taken. Particular aention will be given to avoid all types of pollu- ing material will be eliminated in the appropriate way. Recyclable tion in karstic areas, as in such places contamination may spread packaging will be preferred whenever possible. The construction faster and over greater distances than in any other soil types. force will be trained in the safe and proper use of fuel and chemi- cals and instructed in non-damaging disposal. Safety (human and Operation Related Impacts environmental) measures (legal as well as commonsense) will be The creation of the reservoir, the water quality of the reservoir, the controlled and enforced. diversion of water from the Nam Theun to the Xe Bang Fai, the Use of Explosives interruption of fish migrations and the destruction of spawning grounds will all have long-lasting impacts on aquatic habitats and Use of explosives in water is highly damaging for fishes and other biodiversity. They are presented in the section below. Other poten- aquatic organisms. If they are not killed instantly, their internal tial impacts to rivers are presented at the end of the section. Mitiga- organs may be severely injured leading to death within a few min- tion measures are discussed whenever possible. utes to a few days, even if they were at a considerable distance from the explosion site. In theory, lile or no explosives will be Reservoir Creation used underwater during construction of the Project. However The creation of the reservoir will have the following effects on the experience shows that at most construction sites, large quantities aquatic environment: transformation of the habitat from a lotic ofexplosivesarestolenordivertedfromtheirpropergoalandused environment (a flowing river with rapids) into a lentic environ- for fishing. Besides being illegal, fishing with explosives is a very ment (largely stationary water); creation of a relatively barren inefficient method as most killed fishes cannot be recovered.Addi- underwater landscape; increased water turbidity and tempera- tionally, the explosives damage the fish habitats and occasionally ture; seasonal fluctuations of water level; potential introduction of kill fishermen. As these occasional "fishermen" are usually Project exotic plants and animals; and changes in water quality. workers, this issue is also of concern for Project security. Impacts on native fish fauna: Species which need fast-running Mitigation: Explosives will not be used in the riverbed. Fishing waters will be negatively impacted or eliminated from the area with explosives by Project workers will be banned and the ban will (e.g. Bangana elegans, Barilius pulchellus, Garra theunensis, Onychos- be enforced. toma fusiforme, Scaphiodonichthys acanthopterus, most species of the Vegetation Clearing families Balitoridae, Sisoridae and Gobiidae). In order to reduce the extent of any anoxic conditions that may Because of sediment deposition, most of the stones, rocky outcrops Impacts develop in the initial years aer the inundation of the reservoir, and other elements of the underwater landscape will progressively some vegetation will be cleared from the inundation area. This will disappear. These are the main habitats of the species listed above. result in some short-term increased sediment load in the river dur- Algae living on the stones will disappear, as well as the inverte- ing the wet season. Early removal of riverine forest will affect the brate fauna associated with them. Fish feeding on these algae and riverine fish stocks by reducing food supply leading to reduced fauna are unlikely to switch to other food sources and will disap- stock abundance, which in turn will negatively affect the founding pear. Sediments may cover spawning grounds and affect most of stock once the reservoir is filled. the species of interest to the local subsistence fisheries: Bangana sin- kleri, Garra theunensis, Onychostoma fusiforme, Poropuntius carinatus, Mitigation: Several measures to reduce the transport of sediment Scaphiodonichthys acanthopterus and Scaphognathops theunensis. to the main river will be taken, including proper road construc- tion and sediment traps. Sediment traps will be checked frequently It is not certain whether submerged aquatic macrophytes will be and maintained. Sediment will be transported to proper disposal abletodeveloponthenewsubstrateorcopewiththefluctuationsin areas. The riparian forest along the Nam Theun will be kept intact water level.Algaewillprobably develop,but it isnot clear whether until dam closure, keeping a 50-100 m forest corridor along the the species presently growing on stones in fast flowing water will river. This corridor will have two main functions: i) it will con- be able to develop on a so substrate. Whether those algal species tribute to trapping sediments, ii) it will keep the riverine habitat growing on the so substrate can be used by the algae-eating fish intact as long as possible. If the riverine vegetation is eliminated now inhabiting the Nam Theun is be open to debate. Most of these right at the beginning, the siltation will increase and most fish will fishes scrape algae with the trenchant edge of their lower jaw and lose their food source, either allochtonous (insects, fruit etc. falling it is not known whether they are able to switch to other ways of in the water) or autochtonous (algae, invertebrates, etc.) and the handling their food items. fish population will be seriously decreased before the reservoir is The increased water turbidity will negatively affect all the species flooded. For fish to have a chance to adjust to reservoir conditions presently living in the Nam Theun mainstream. The real impact of and develop healthy populations, it is important to keep the origi- increased water temperature cannot be predicted, but it will result nal (founder) stocks as healthy as possible. in decreased oxygen concentration and the two factors might place Limestone Extraction in Karstic Formations some species under stress. The seasonal fluctuations of the water level will affect a signifi- Karstic formations usually include underground water bodies and cant part of the reservoir area within which limited terrestrial and streams that may host a very specialised, highly endemic fauna. aquatic life will be possible. Most of the Nam Theun fishes will Exploitation of limestone for construction work may threaten this probably be unable to use this area. Those species presently occur- component of biodiversity if quarries are located in these areas, ring in the swamps of the Nakai Plateau should have no difficulty either directly by destruction of the habitat or indirectly by pol- in colonising these habitats, but they are among the less interest- lution. ing species from the biological diversity point of view because Mitigation: The sites where limestone will be quarried and the they are widely distributed and abundant throughout the Mekong location where the downstream channel passes through karst will basin. Impact on Nakai Plateau floodplain: The total surface area be surveyed for possible presence of caves and springs. As this is of the current floodplain on the Nakai Plateau is approximately part of a very extensive karstic area, it is very unlikely that lime- 27 km2. Aer closure of the Nakai Dam, the reservoir waters at stone extraction will threaten any endemic species. If any caves are FSL will cover the entirety of this floodplain. During drawdown 104 Aquatic Habitats & Fish Diversity EAMP Main Text however, the floodplain will become exposed, and the reservoir but not restricted to, extinction of native species and sometimes will become largely confined to the existing Nam Theun. The exist- extinction of the subsistence fisheries, introduction of pathogens ing floodplain would therefore be converted into reservoir habitat (to both humans and animals), and habitat destruction (Koelat, for part of the year, and revert back to floodplain habitat during 1996b). The native aquatic fauna of the Nam Theun, already put at the remaining. The implication is that the total area inundated is stress by the Project, would be put under more stress if exotic fish in reality a reservoir/floodplain complex rather than a reservoir in species are introduced to the reservoir. This would affect not only the conventional sense. When inundated, the drawdown zone will the reservoir but could affect fish populations in the NNT NBCA likely be used by the reservoir fish stocks as a large breeding, nurs- as well. ery and forage habitat. Taken alone, any of these factors may have significant impacts on Impact of water level fluctuation: The seasonal fluctuations of the the different fish species, but may not be enough to place them at water level will affect living conditions for aquatic and terrestrial risk. When the factors are combined there is a synergistic effect fauna. Under infrequent extreme conditions a maximum draw- and a great likelihood that many species will simply disappear down of 12.5 m from FSL would cause 81.8% of the reservoir area from the reservoir. (i.e. 368 km2) to become exposed. This may lessen the impact of habitat modification in peripheral areas of the Nakai Plateau that Table 3.50 indicates the known or guessed adaptability of the Nam will be flooded for limited periods. Some wetland areas currently Theun fish species to reservoir conditions and habitat modifica- existing during the wet season are likely to persist and may ben- tion. For most species, no concrete data exist and the adaptability efit from greater water supply. These areas will continue to func- has been guessed on the basis of their known ecological require- tion more like floodplain/wetland habitats rather than reservoir ments. In some instances, we know that related species in other habitats. Drawdown may result in stranding of fish in small water areas have or have not adapted to reservoir conditions. bodies in some areas. When the reservoir is at FSL, a number of The extensive swamps and man-made reservoirs already existing islands will be formed, particularly in the western end of the reser- on the Nakai Plateau possibly give an image of what the aquatic voir area, and contribute to shoreline development which in turn community might be in most of the future reservoir. Their fauna is generally beneficial to the productivity of lioral fish species. consists of only a few ubiquitous species (Hampala macrolepidota, However, a large drawdown over a limited time period will result Channa striata, Clarias batrachus and Anabas testudineus) found in a rapid lateral displacement of the shoreline. This could nega- throughout Southeast Asia and species known elsewhere to live Impacts tively impact fish which breed in shallow water during this period exclusively in swamps and standing waters (Lepidocephalichthys by forcing them from breeding habitats, stranding larvae and fry, aff. hasselti, Trichopsis schalleri, Oryzias sinensis and Odontobutis and/or leaving spawn undefended against predators. The draw- aurarmus). A few other species will be present, in smaller num- down phase will concentrate fish stocks into a smaller residual vol- bers: Cyclocheilichthys repasson, Puntius aurotaeniatus, Rasbora ume of reservoir water, and this `concentration'effect will increase paviei, Danio fangfamgae, Pangio fusca, Channa gachua, and possibly the catchability of fish. Hypsibarbus vernayi, Mystacoleucus marginatus and Mastacembelus Infestation by floating macrophytes: There is a potential for float- armatus. Rhodeus laoensis may be present if the mussels it needs ing macrophytes such as Eichhornia or Salvinia to become estab- as a symbiotic host for its eggs and larvae are able to survive. The lished in the reservoir and form large floating mats. The infestation adaptability of Hemiculterella macrolepis, Poropuntius carinatus, Raia- results in localized deoxygenation below the mat and an increase mas guatus, Hemibagrus wyckoides and Pterocryptis inusitatus can in acidity, which can cause a reduced fish production in affected only be guessed. Several of the adaptable species are very widely areas. Infestation also affects fishing activity, navigation and can distributed in the Mekong basin or in Southeast Asia and are of damage turbines in the power station. Water level fluctuations of lile conservation value. the magnitude predicted for the Nakai Reservoir will contribute Mitigation: There is no direct mitigation for many of the impacts substantially to the control of floating macrophytes by stranding in the reservoir area and it will be more efficient to concentrate on and desiccation. This has been the experience in other reservoirs compensation actions, particularly in the protection of the NNT with a high dam wall (Bernacsek, 1984, 1977). NBCA. Most of the species at risk in the reservoir area also occur Drawdown zone vegetation: The drawdown zone will likely upriverandanefficientandsoundmanagementoftheNNTNBCA become covered in terrestrial vegetation tolerant of temporary will ensure the safe survival of the species as long as they do not inundation. Wind fetch across the plateau will likely aerate lio- need extensive migrations for the completion of their life cycles. ral water and reduce the deoxygenation effect of annual inunda- The fragmentation of their range will result in the genetic isolation tion of the vegetation. Drawdown vegetation will produce large of the populations in the different tributaries. Except for large size quantities of biomass and become the basis of the trophic web in species with low population densities and possible migration (Tor the drawdown zone. The annual input of nutrients from drowned lateriviatus, T. tambroides, Scaphognathops theunensis, Luciocyprinus vegetation will allow substantial productivity of fish stocks, and striolatus and Bangana elegans), this should not have any significant cause the lioral zone to function as a large spawning ground, impact. But, as fast swimmers and large predatory fish, the popu- nursery and foraging area, and contribute to reservoir fish pro- lation density of Luciocyprinus striolatus is probably low and the duction. Rooted aquatic macrophytes may not become abundant fragmentation of its range could be a significant impact. Accumu- in the reservoir because annual drawdown of greater than 3.5 m lations of boulders and stones could be created at different depths negatively affects rooted aquatic macrophytes (Bernacsek, 1984). and in areas where they will not be covered by deposited silt to However some species may survive in residual wetlands, thus compensate for the rocky habitats that will be lost. directly contributing to the food supply of herbivorous fish spe- Landscapingofpartofthefloorofthereservoircouldavoidthefor- cies, and providing extensive surface areas for periphyton growth mation of small lakes where fish can be trapped and subsequently which are eaten by grazing fish species. stranded when the water lever decreases. Priority areas should be In many reservoirs exotic species of plants and animals have determined for protected fish sanctuaries where the main tributar- been introduced, voluntarily or not. Very few of these introduc- ies enter the reservoir. tions have had the expected results and very few resulted in a real No introduction of new species is planned for the reservoir for at increase of fish productivity. Most introductions have had very least the first 5-10 years. This is the minimum time required for negative impacts on the native aquatic communities including, the local aquatic communities to stabilise aer creation of the res- Aquatic Habitats & Fish Diversity 105 EAMP Main Text Table 3.50: Fish species of the Nam Theun basin, their known or guessed adaptability to reservoir conditions and distribution Family (Species) Adaptability Distribution Family (Species) Adaptability Distribution Cyprinidae Sisoridae Bangana elegans Unlikely to adapt Endemic Glyptothorax laosensis Not adaptable Limited Cirrhinus molitorella Adaptable Wide Glyptothorax macromaculatus Not adaptable Limited Cyclocheilichthys repasson Adaptable Wide Glyptothorax zainaensis Not adaptable Limited Danio fangfangae May adapt Wide? Oreoglanis hypsiurus Not adaptable Endemic Folifer brevifilis Not adaptable Wide Pseudecheneis sympelvicus Not adaptable Limited Garra cambodgiensis Not adaptable Wide Oryziidae Garra cf cyrano Not adaptable Limited Oryzias pectoralis May adapt Wide Garra theunensis Not adaptable Wide Oryzias sinensis Adaptable Wide Hampala macrolepidota Adaptable Wide Odontobutididae Hemibarbus cf. umbrifer May adapt Wide Neodontobutis aurarmus Adaptable Limited Hemiculterella macrolepis Unlikely to adapt Wide Gobiidae Hypsibarbus vernayi May adapt Wide Rhinogobius lineatus Not adaptable Limited Luciocyprinus striolatus1 May adapt Locally restricted Papuligobius ocellatus Not adaptable Wide Mekongina erythrospila Unlikely to adapt Wide Anabantidae Mystacoleucus marginatus Unlikely to adapt Wide Anabas testudineus Adaptable Wide Neolissochilus stracheyi Not adaptable Wide Osphronemidae Onychostoma fusiforme Not adaptable Limited Trichopsis schalleri Adaptable Wide Opsarius pulchellus Unlikely to adapt Wide Channidae Poropuntius carinatus May adapt Wide Channa gachua May adapt Wide Puntioplites falcifer Adaptable Wide Channa striata Adaptable Wide Puntius aurotaeniatus Adaptable Wide Mastacembelidae Raiamas guttatus Unlikely to adapt Wide Mastacembelus armatus May adapt Wide Rasbora paviei Unlikely to adapt Wide Ambassidae Impacts Rhodeus laoensis May adapt Endemic Parambassis sp. May adapt Limited Scaphiodonichthys acanthopterus Not adaptable Wide Scaphognathops theunensis May adapt Endemic Tor ater Unlikely to adapt Endemic ervoir. If anoxic waters develop in the reservoir at some locations Tor cf. tambra May adapt Wide and for some time, this stabilisation period will be longer. Aquac- Tor tambroides May adapt Wide ulture development of the reservoir will focus on species already Tor laterivittatus May adapt Limited/wide? locally present (e.g. species of Tor and Bagarius, Hemibagrus wyck- Gyrinocheilidae oides, Bangana elegans, Hypsibarbus vernayi, Luciocyprinus striolatus Gyrinocheilus amonieri Not adaptable Wide and Scaphognathops theunensis) and there is no requirement to introduce exotic species. The potential benefit of such introduction Balitoridae is by far outweighed by the potential threat of disease and decline Balitora cf. annamitica Not adaptable Limited in biodiversity. Balitora lancangjiangensis Not adaptable Wide Hemimyzon papilio Not adaptable Limited Species occurring in the lower Nam Theun in quieter stretches might be stocked into the reservoir, but their potential impact on Homaloptera smithi May adapt Wide the native fauna should first be carefully examined using the Food Nemacheilus arenicolus Unlikely to adapt Endemic and Agricultural Organisation (FAO) guidelines and code of prac- Schistura sombooni Unlikely to adapt Limited tice (Coates, 1995). Other species from the lower Nam Theun that Schistura kongphengi May adapt Limited might develop in the reservoir are Puntioplites falcifer and Cirrhinus Schistura atra Not adaptable Endemic moliorella. Schistura nudidorsum Not adaptable Endemic From a fisheries point of view it is important to plan the final clo- Schistura obeini Not adaptable Endemic sure of the dam between the months of July and October. Dur- Schistura dorsizona Not adaptable Limited ing the month of June aer the first rainfall of the wet season, Schistura sp big head Not adaptable Endemic? many fish species migrate upstream for spawning. Some of these Schistura tubulinaris May adapt Endemic upstream migrating fish species migrate downstream in July while Cobitidae the majority ofspeciesmigrate downstreamin October/November. Lepidocephalichthys aff. hasselti Adaptable Wide If closure takes place between July and October, a large number of Misgurnus anguillicaudatus Adaptable Wide fish species will be trapped in the reservoir, including fish larvae Pangio fusca May adapt Wide and juveniles. This will benefit production of fish during the first Bagridae months aer inundation and will accommodate a higher fish yield Hemibagrus wyckoides Adaptable Wide than if the dam was closed at another time of year. Experience from Pseudomystus siamensis May adapt Wide otherregionalreservoirsshowsthatthereductioninthe number of Siluridae species may be an artefact created by inappropriate closure sched- Pterocryptis inusitata Unlikely to adapt Endemic ule (Bernacsek 1997). However most of the species which really need to migrate upstream also need to return downstream. Most Clariidae of these species prefer rapids and they will not be able to grow in Clarias batrachus Adaptable Wide the reservoir. 106 Aquatic Habitats & Fish Diversity EAMP Main Text Reservoir Water Quality Shallow water gravel beds (e.g. downstream of the Nam Phit Decompositionofsubmergedvegetationwillaffectreservoirwater confluence) will be permanently flooded, at least until the river chemistry during the first few years in what is termed the `trophic deposits new gravel beds. With the loss of these gravel beds, sev- upsurge' phase. Impacts include: i) local deoxygenation of the eral species may disappear from that reach of the Xe Bang Fai (e.g. water column, leading to stress and avoidance by fish, ii) produc- Schistura daubentoni, S. isostigma, S. punctifasciata, Nemacheilus long- tion of toxic gases (ammonia, methane and hydrogen sulphide), istriatus, Serpenticobitis zonata, Amblyceps serratum).All of these spe- and iii) release of nutrients into the water column (leading to phy- cies were observed in the Xe Bang Fai upstream of the Nam Phit toplankton blooms and enhanced fish productivity and bumper confluence or in other river basins. As a consequence, their future catches). At some concentrations, hydrogen sulphide and ammo- is not at risk, assuming that they are not threatened in the other nia are toxic for aquatic organisms. The exact lethal concentrations parts of their distribution. may vary from species to species and there may be a synergistic Apparently, the remaining species and communities may not be effect with other factors (temperature, presence of other chemicals, affected by the change in water level. The habitat of some could be presence of pathogens, etc.). Only very few fish species are able shied laterally. Our knowledge of the life history and ecology of to survive in anoxic waters more than a few minutes and they all these fishes is still too limited to allow a prediction of the possible belong to species with the least conservation value. impact of these changes. The main impact will be the transforma- Mitigation: Water quality mitigation measures are discussed in tion of the Xe Bang Fai from a river with cycles of shallow-slow more detail earlier in the chapter. Vegetation will be removed and deeper-swi river into a permanent deep and swi river, even before flooding the reservoir. This clearance is not limited to valu- during the dry season. It is likely that a significant number of spe- able timber but also includes non-commercially valuable timber cies will not be able to survive locally under these permanent con- collected for firewood. The priority shall be to clear the vegeta- ditions and a lowering of fish diversity and productivity is to be tion in areas which will be permanently flooded. The results of expected. In the case of the Theun Hinboun project, a significant the ongoing biomass survey of the inundation area will be used diminution of standing crop has been noted since the start of the to as a means for maximizing removal in areas of high biomass. operation. The vegetation along the Nam Theun will be removed at the last The diversion will introduce cooler water into a warm lowland moment in order to reduce the stress to the aquatic community. river. This difference in temperature will be reduced by passive Impacts Trees that are le standing form important surfaces for periphy- warming of the water in the 27 km run from the power station to ton growth, and will provide forage and shelter for some fish spe- the Xe Bang Fai.Aeration of the water in the Downstream Channel cies. This is particularly important in the deep water pelagic zone willalsoassistthiswarmingprocess.Inthedryseason,thetemper- which will otherwise be a largely featureless landscape. In the ature difference is expected to be less than 3.5° C in the upper Xe drawdown zone which is only temporarily flooded, tree species Bang Fai. In the wet season, the differential will be less, and will be that normally withstand regular floods will not be removed, but buffered by greater quantities of water in the Xe Bang Fai. Alone, can be harvested later if they do not survive. These tree species the change in temperature is possibly not significant (Koelat, pers. might create new habitats for fish populations in terms of refuge com.), but in synergy with the other impacts it could significantly and spawning, and a substrate for algal growth and invertebrate increase the stress on the aquatic community. Fish are sensitive to refuge which the fish feed upon. rapid changes in temperature, which can result in stress and leave them susceptible to diseases, especially fungal infections. In the To monitor the evolution of water quality within the reservoir, wet season, the quantities of water in the Xe Bang Fai will buffer a water quality monitoring programme will be developed, the the Power Station discharge. In the dry season, the Xe Bang Fai outputs of which will assist in decision-making processes of the will be mostly comprised of the Power Station discharge and will Reservoir Fisheries Management Plan (RFMP) and help in the for- largely take its characteristics from this discharge. Because of this, mulation of appropriate mitigation measures and adaptive man- sudden temperature changes in the Xe Bang Fai are not expected. agement strategies. Details of the programme objectives, method- ology and its inter-programme coordination with the RFMP are It is known from other areas that rapid increase of the discharge in discussed earlier in Chapter 3. tributaries, lower water temperature and changes in water chemis- try are among the stimuli that initiate the start of migratory move- Water Diversion ments. The diversion of Nam Theun waters into the Xe Bang Fai Diversion of Nam Theun waters into the Xe Bang Fai will have and then the Mekong may enhance wet season conditions and thus the two obvious consequences of increased flow in the Xe Bang affect some species by providing an increase in flooded areas, in Fai and reduced flow in the Nam Theun, with several secondary the lower Xe Bang Fai. For spawning and nursery grounds, the consequences including changes to water quality. long-term impact of these changes is not known. The LARREC and Warren study outlined earlier in this section will give an indication Increased Xe Bang Fai Flow: The increased flow in the Xe Bang of how the fish populations respond to the increased discharge, the Fai will result in the increase of the minimum water level in the change in the channel configuration, and to the potential effects on river. Several habitats will definitively disappear, some may be dis- water quality in the Xe Bang Fai. placed and others will be altered. Several dry season rapids will be permanently flooded and some extensive rocky outcrops that form Mitigation: Mitigation methods to help minimize impacts result- permanent rapids will be dis-placed. Some stretches functioning ing from erosion and water quality are discussed earlier in the as rapids only during high discharge may become permanent rap- Chapter; including the Regulating Dam, the Aeration Weir and ids. It is likely that most rapids-inhabiting species could be able to bank protection at the Downstream Channel confluence. In terms adjust to these shis. of the quantity of discharge, operations of the Regulating Dam will limit any increases in discharge to 20m3/s/hr which should prevent More significant is the fact that some of the rapids may be spawn- flash flooding but also dampen any discharge stimuli for migra- ing grounds. Some species may need shallow waters in the rapids tion. To sustain fish populations that may develop in the Nam Phit, for spawning and an increased water level may have significant NTPC will release a guaranteed 30 m3/s during the times when the negative impact on their reproductive success. The lack of reliable Power Station is not generating. This guaranteed release can be information on fish reproduction and migration does not allow sustained for a period of 32 hours. Any socio-economic impacts further discussion of this impact. resulting from the modified discharge regime will be either miti- Aquatic Habitats & Fish Diversity 107 EAMP Main Text gated or compensated for as detailed in the Xe Bang Fai Strategy the distance they travel or the obligate character of the migration of the SDP. One compensatory option is a fisheries replacement is not known. programme to replace any losses of fish currently caught in the The degree of adaptability of migratory species is also not exactly Xe Bang Fai. The programme could include (i) stocking fish in rice known. Thus, when the dam is closed, migratory species may: i) fields; (ii) introducing fish ponds into irrigated areas; (iii) introduc- disappear for reasons not related to migration (habitat destruction, ing irrigation, rice-fish and fish ponds to existing rice fields; and pollution, etc); ii) be unable to reproduce because they cannot com- (iv) cage culture. Improvement of natural fisheries management plete their migration; oriii)be able toreproducewithout migration could increase fishery yields significantly and thus help counter or find new migratory routes and spawning sites. Some migratory any losses resulting from the Project. fish species may travel relatively long distances between precisely Reduced Nam Theun Flow: The reduced flow in the Nam Theun delimited feeding and breeding grounds. Long distance migra- willresultinadecreaseinwaterlevelcomparedtothepresentlow- tory fish are already impacted by the Theun Hinboun project dam est level, but the existing morphologywill onlybe slightly affected. that obstructs the Nam Theun some 100 km downstream of the The deep pools will remain and large species, which would be proposed Nakai Dam. Others may migrate for a few kilometres affected by the decrease in absolute water volume, would likely between different places within the main river, or between the take refuge in these pools. Runs, riffles and rapids will become main river and tributaries. It is objectively impossible to assign narrower and shallower, with slower water. The slower water may these species to any of these categories, but it seems that Bagar- affect the survival of some species of Balitoridae and Sisoridae will ius yarrellii and Hemibagrus wyckioides may migrate over relatively likely reduce population size. It will very significantly reduce the long distances in the Nam Theun basin. In many localities of the habitats suitable for the endemic Scaphognathops theunensis. The lower and middle Nam Theun and on the Nakai Plateau, the pres- virtual suppression of most of the seasonal, cyclic successions of ence of juveniles and large adults of the two Tor species indicates low and high waters will probably have a much more significant that they probably have several spawning grounds and possibly impact on the aquatic diversity than the reduction of the minimum do not undertake extensive migrations. flow. It is likely to severely affect their growth, reproduction and Spawning Grounds: As well as the presence of barriers to long- migrations. range migrations, such as the Theun Hinboun dam further down- stream on the Nam Theun, a problem remains for those species For many species, variations in the water discharge play an impor- migrating only in the Nam Theun (between the lower Nam Theun tant role as a stimulus for the start of migration. Suppression of and the Nakai Plateau or the headwaters). Such fishes may be this stimulus may seriously affect migrations in the Nam Theun more numerous than the species involved in long-distance migra- below the dam, but also between the Nam Theun and its tributar- Impacts tions, but they may be more likely to have numerous spawning ies, such as the Nam Phao, (ie tributary flow will be greater than grounds in the basin and so be able to pursue their lifecycles in mainstream flow, and aract migrating fish away from the main- the tributaries of the reservoir or downstream from the reservoir, stream). Several fish species which typically select lentic habitats providing that the minimum discharge is sufficient. The presence may become established and compete with rheophilic species. The of juvenile Tor laterivitatus of apparently the same size class (20-40 occasional flood spills from the reservoir may be the source of such mm) in numerous stations across the whole Nam Theun basin sup- species, as well as upstream migrants from Nam Theun-Hinboun ports this hypothesis. This also seems to apply to Bangana elegans, reservoir and intermediate tributaries. for which juveniles of apparently two size classes occur both in the A permanent low water level will have a negative impact on fish headwaters and downstream of the dam site. The flooding of the as it will drastically reduce the available food sources, reduce the Nakai Plateau will probably result in the destruction of part of the number of hiding places and increase predation (by other fish as spawning grounds of some species, but as the data on reproduc- well as terrestrial animals and humans) and will increase their sen- tion biology and migration are incomplete, and as there is no pre- sitivity to diseases through increased stress. cise information on the location of spawning grounds, it is difficult to comment on this aspect. Mitigation:ModificationsoftheNamTheunrivertopographywill narrow some rapids, in areas where the river is wide and shallow, Mitigation: Fish ladders have been constructed at many dams to and will maintain stretches of deep and fast rapids. As the fishes allow for fish to migrate. The concept has been developed in north- most interesting from the biodiversity point of view are specialised ern and temperate countries of Europe andAmerica and has some- for rapids, this can be an important mitigation and compensation times worked. They work mainly where the fish fauna consists of for the loss of habitats. only one or two species for which the fish passage facilities are spe- cifically designed. These are mostly trout and salmon, fishes that Interruption of Fish Migrations & Destruction of Spawning are known to be good jumpers, and the ladders (a succession of Grounds: closely set weirs with resting pools) are not obstacles to migration FishMigration:ThecompletionoftheNakaiDamwillblockpossi- Fish ladders (or fishways) have rarely been constructed in tropi- ble migrations between the Nakai Plateau and downstream areas, cal countries, and when they have, they were of a wrong design from the Nam Theun above the Theun Hinboun project. Upstream or of inappropriate size, as at the Pak Mun Hydropower Project migration across the Nakai Dam will be completely blocked to in Thailand. There is no report of instances were they have been species occuring in the lower river section. Downstream migra- efficient, but there are accounts of their inefficiency (Roberts, 1994). tion will be theoretically possible via the occasional flood spillage. These failures can be aributed to poor construction (ladders lead- Information on fish migrations in the Nam Theun is at present ing from a dry place of the river to a place in the reservoir that incomplete and somewhat contradictory, and does not allow clear is dry at the time of migrations), poor or no maintenance (ladder conclusions about which fish migrate, during which season and filled by sediments in a few days) and poor design (lack of bio- for what purpose. logical considerations). Important biological considerations are: i) tropical fish communities usually include numerous species The following species observed in the Nam Theun seem to under- (sometimes more than a hundred) and each species may have dif- take migrations: Bangana elegans, Hypsibarbus vernayii, Scaphognath- ferent requirements in terms of season, hydrodynamism, position ops theunensis, Tor tambroides, Tor lateriviatus, Bagarius yarrellii and in the water column, and swimming behaviour; ii) fish must find possibly Hemibagrus wyckioides. The exact timing of the migration, the entrance to the ladder; and iii) aer ascending a ladder, the 108 Aquatic Habitats & Fish Diversity EAMP Main Text fish (or their offspring) will have to come back down through the The Nam Phit is dry most of the year for most of its course. Only barrier structure, i.e. the dam. For example, migratory catfishes the lowermost reach has permanent water. The Project will trans- usually follow the boom of the river and are unlikely to find the form the middle and lower Nam Phit from a temporary stream entrance to a fishway located along the shoreline. As all fishways with a dry riverbed most of the year, into a wide channel with constructed in tropical locations to date have been of the "salmon" constant flow. As there is no permanent aquatic diversity (the type, catfishes, which are not able to jump out of the water, cannot stream is repopulated from downstream populations during each use the ladders. This example could apply to most other tropical wet season), the impact on it will be very limited. Re-aeration of fish species. the water in the Downstream Channel should make dissolved Water Pollution oxygen suitable for the establishment of fish populations. But the species likely to colonise such a channel will probably be differ- Any increase in the use of pesticides, fertiliser and other synthetic ent from the original Nam Phit fauna and may take several years chemicals associated with Project activities has the potential to to become fully established and flourish. The present lower Nam elevate their concentrations in the surrounding water. Although Phit community will be unable to establish viable populations in low concentrations of these synthetic chemicals may not be acutely the channel as the current will be too swi. The lower Nam Phit toxic to aquatic organisms, they may exhibit chronic effects and fish fauna is typical of sluggish streams and most species have not potentially bio-accumulate to levels that are harmful to humans. been observed in the mainstream Xe Bang Fai, where dry season Mitigation: A Pest Management Plan has been developed to flow is inferior to the channel discharge. The fish in the Nam Phit ensure the safe storage, use and disposal of synthetic chemicals. A currently survive the high water discharge in the wet season by detailed discussion of this occurs later in this chapter and the Pest moving laterally into the flooded lowlands. Management Plan is presented in Annex M. The Downstream Channel will pass through a small seasonal Potential Impacts by River Sector wetland downstream of the tunnel. It is part of the floodplain of Potential impacts and mitigation measures are listed here by river the Nam Phit. Depending upon how the channel is constructed sector and refer to the above descriptions of the different impact throughthiswetlandarea,partsofthewetlandcouldbemaintained types. The potential impacts resulting from Project operations on or could be drained. However, the wetland may be recharged on the Nam Theun and Xe Bang Fai, together with the mitigation occasion when discharge in the Downstream Channel is greater Impacts measures, are presented above. Additional aspects, unique to a than the two-year flood event. given sector, are also discussed (Table 3.51). The annual in-migration of large fish species from the Mekong and Nam Theun Headwaters Xe Bang Fai into the flooded forest will likely continue in some form (although it is likely that the forest itself will be altered by the If the NNT NBCAis properly and successfully managed, integrat- change in hydrology). It is not clear what effects there will be on ing social and biodiversity issues, the Project is not likely to have the migration of fish into the caves of upstream tributaries of the much impact on the headwaters of the Nam Theun. If the NNT Nam Phit, or on the annual spawning aggregation and fishery for NBCA management is not enforced, then the following impacts Schistura or Nemacheilus sp or spp at the confluence of the Nam can be predicted: deforestation and the resulting rapid siltation Phit with the Xe Bang Fai. During the first few years, diversion of most riverbeds; overfishing, introduction of exotics and their flow will likely cause some change in water quality of the Nam pathogens, and pollution with pesticides. Phit. Flooding of terrestrial vegetation will release nutrients but Some species may migrate between the headwaters and the main deoxygenation is not likely to become a major problem due to Nam Theun on the plateau and unsuitable habitat in the reservoir downstream flushing and mixing with well oxygenated water in maynegativelyimpacttheirpopulations.However,thisshouldnot the Xe Bang Fai. There may also be some erosion and consequent lead to extinction as it seems that they should still be able to find increase in turbidity which could affect some sensitive fish species. acceptable conditions at the river mouths to support smaller popu- Eventually the Nam Phit channel should stabilize under the new lations. Species needing to migrate between the headwaters and discharge regime, which would only be temporarily and infre- the middle or lower Nam Theun are likely to disappear locally. quently disrupted by Power Station shutdown episodes. Nam Phit Mekong Mainstream Table 3.51: Main potential Impacts by river sector Main Potential Impacts Additional Aspects Unique to the Sector/Remark Reservoir area Reservoir creation and reservoir water quality. Some of the fish species present in the reservoir may disappear if recruitment is dependent on migration between the plateau and downstream. Nam Theun between Dam Site & confluence with the Nam Phao Construction period, reservoir water quality, reduced Nam Theun discharge and interruption of fish migration. Nam Theun downstream of confluence with Nam Phao Construction period, reservoir water quality, reduced Nam Theun discharge and Adverse impacts may be more serious because of synergistic effects with impacts of the Interruption of fish migration. Theun Hinboun Project. Middle and lower Xe Bangfai Reservoir water quality and increased Xe Bang Fai discharge. Importance of fish to the human population along the Xe Bang Fai. Underground water in Khammouane Limestone NBCA and other karstic formations Construction period and reservoir water quality. Such environments are extremely sensitive, especially to pollution. As there is no known connection between the Nakai Plateau and the karstic formations, pollution is only a remote possibility. Aquatic Habitats & Fish Diversity 109 EAMP Main Text Changes in the run-off and probable changes in the water tempera- alternately temporarily quartering fish in floating cages inside the ture and chemistry of the Nam Kading, Nam Theun and Xe Bang ponds and ricefields until the flood recedes. Some trap ponds on Fai may interfere with the natural stimuli responsible for the start the Nakai Plateau floodplains are likely to be seasonally or per- of migration, but the biological data is not available to speculate on manently flooded. The Project will create new opportunities for this. Most Mekong fish do not spawn in the Mekong mainstream cage culture in the reservoir and possibly also in some peripheral but enter flooded areas and the tributaries, usually during the wetlands, which would readily compensate losses. wet season, to spawn (Taki, 1978). Some travel only a few hun- dred metres while others may undertake extensive travels (usually Terrestrial Biodiversity large-size species, including Bangana behri, Cirrhinus microlepis, C. molitorella, Probarbus spp). Tributaries are of the utmost importance for Mekong mainstream fish; without access to tributaries, most Baseline stocks would be negatively affected and some may even disappear. This section examines forest diversity and wildlife resources that It is likely that the increased discharge in the Xe Bang Fai may occur in the inundation zone (Zone 1), the dividing hills (Zone instigate spawning migrations into the river. However, this can 2), the reselement area (Zone 3), and the area downstream of only be observed once the Project is operating. the Nakai Dam (Zone 4). These Zones are the major ecosystems The increase in average flood discharge during the wet season of affected by the Project. the Xe Bang Fai will result in a larger area of floodplain inunda- Units of Biodiversity & Zoogeography tion in the lower Xe Bang Fai and this should contribute to fish production. The area of the Project straddles two regional biotic units. The reservoir and drainage basin (Zones 1 to 4) are located in the Potential Impacts on Fisheries Annamite (Trung Son) mountain chain, while the Power Station, Nam Theun Fisheries Downstream of the Nakai Dam Downstream Channel, and Transmission Lines (Zones 7, 8, 13 and Fishing in the lower Nam Theun will be heavily impacted by the 14) are in the Central Indochina lowland plains. A number of new Nakai Dam due to a severe reduction in discharge (both during species of mammals, birds, fish and plants have been discovered in the wet season and the dry season) and due to blockage of fish the Annamite Mountains, which is recognised as an area of global migration. This will result in deterioration of the fish production significance in terms of biodiversity (Baltzer et al., 2001; Wikrama- habitat and the fishery stock itself. A more detailed description of nayake et al., 2002; Koelat, 1998). Wildlife species of global and the impacts of the Project on the fisheries of the Nam Theun and national conservation significance recorded in the NNT NBCAare listed in Table 3.52 and the full list of mammals, birds, reptiles and Impacts the possible mitigation measures are presented in the Riparian Release section. amphibians recorded in the area is presented in Annex J. Fisheries Resources and Fishing Methods of Nakai Plateau and The regional climate and the diversity of geological conditions in Reservoir this area have fostered a wide variety of habitat conditions. The climate of the area is postulated to have led to a highly diverse The floodplain and riverine fishery of Nakai plateau will be trans- formed into a reservoir fishery, with some residual floodplain deciduous forest at the expense of evergreen forests. At one time, characteristics. The existing river fishery will largely cease to the Nakai Plateau maintained an extensive coniferous forest that exist in its current form during the wet season due to inundation had its own set of flora and fauna. The combination of moist tropi- of the river channel and blockage of upstream fish migration by cal forests of the higher Annamites and generally cooler lowlands the Nakai dam. During the dry season drawdown a portion of the inIndochinaledtoagreaterexpanseof"new"grasslandsandallu- original river channel will re-emerge, but fishery conditions will vial marshlands with their representative fauna such as tiger, Eld's not be equivalent to pre-impoundment in terms of the fish stocks deer, hog deer, rhinoceros, elephant, kouprey, banteng,water buf- which will be present (ie some rheophilic species will be replaced falo and other related extinct forms (Lekagul and McNeely, 1977). by lentic water species). Various residual aquatic refuge habitats The contemporary mammalian faunas are more or less island rem- will continue to exist in the drawdown zone. These will possibly nants and many of them have only been discovered at the end of benefit from an increased water supply which could prevent some the twentieth century. Thus, a faunal collision of lowland Asian wetlands from desiccating by the end of the dry season. The major forms, highland forms in Pleistocene refugia, and in-migrants expansion in area of lentic habitats on the plateau will cause a pro- from cooler northern steppes has led to this extraordinarily high liferation of lentic fishery resources to occur. Existing fishing gears diversity, isolation, and endemism. A review of zoogeographic are adequate to harvest most of the species in the reservoir and relationships for Lao PDR in Duckworth et al. (1999) assigns the drawdown zone wetlands. NNT NBCA area to their "Annam" unit, which extends over the mountains into Vietnam and to the South China Sea. Since most of Mitigation: Strategies for developing infrastructure and fishing the catchment is remote, sparsely populated and difficult to access, techniques with the goal of achieving the economical potential a large portion, particularly within the NNT NBCA, remains in of the reservoir fisheries are discussed in the Reservoir Fisheries near pristine condition. Management Plan in the SDP. Fisheries Resources and Fishing Methods of Xe Bang Fai Basin Primary Habitat Elements A detailed discussion on the impacts and mitigation measures for Interacting biophysical (elevation, soil type, moisture, flooding, the fisheries of the Xe Bang Fai is presented in the Xe Bang Fai slope), climatic and anthropogenic factors (logging, burning, agri- Strategy of the SDP. culture, fuelwood collection, hunting, non-timber forest product gathering) have resulted in the development of a mosaic of forest Aquaculture Activity and vegetation types in Zones 1-4. The Project is unlikely to have major impacts on existing aquac- The habitats that will be impacted by the Project are classified ulture (which are generally underdeveloped in the Project area as based on the existing forests and land use types. They include: dry a whole). There is some risk that increased flooding in the lower evergreen forest, mixed deciduous forest, dry dipterocarp forest, Xe Bang Fai could threaten pisciculture in ponds and ricefields. broadleaf and coniferous forest, coniferous forest, lowland river- This can be mitigated by raising bunds to prevent flooding, or ine forest, riparian gallery forest, open woodland forest, savannah, 110 Terrestrial Biodiversity EAMP Main Text Table 3.52: Wildlife species of global and national conservation significance recorded recently in the NNT NBCA and on the Nakai Plateau Scientific Names Common Names GTS NRS Scientific Names Common Names GTS NRS Reptiles Rhinolophus paradoxolophus Bourret's Horseshoe Bat VU PARL Platysternon megacephalum Big-headed Turtle EN ARL Rhinolophus malayanus Malayan Horseshoe Bat 0 PARL Cuora galbinifrons Indochinese Box Turtle CR ARL Rhinolophus thomasi Thomas's Horseshoe Bat NT PARL [Cuora trifasciata] [Chinese Three-striped Box Turtle ] CR CARL Rhinolophus affinis Intermediate Horseshoe Bat 0 PARL Cyclemys dentata Asian Leaf Turtle NT PARL Hipposideros cineraceus Least Roundleaf Bat 0 PARL Pyxidea mouhotii Keeled Box Turtle EN ARL Hipposideros rotalis n/a PARL Sacalia quadriocellata Four-eyed Turtle EN PARL Hipposideros scutinares n/a PARL Indotestudo elongata Elongated Tortoise EN ARL Hipposideros armiger Great Roundleaf Bat 0 PARL Manouria impressa Impressed Tortoise VU ARL Aselliscus stoliczkanus Stoliczka's Trident Bat 0 PARL Amyda cartilaginea Asiatic Softshell Turtle VU PARL Myotis annectans Hairy-faced Myotis NT LKL Physignathus cocincinus Water Dragon 0 PARL Myotis montivagus Large Brown Myotis NT LKL Varanus bengalensis Bengal Monitor 0 PARL Myotis ricketti Rickett's Large-footed Myotis NT PARL Varanus salvator Water Monitor 0 PARL Miniopterus schreibersii Common Bent-winged Bat 0 PARL Python molurus Burmese Python NT PARL Murina huttonii Hutton's Tube-nosed Bat NT LKL Python reticulatus Reticulated Python 0 PARL Nycticebus coucang Slow Loris DD LKL Ptyas korros Indochinese Ratsnake 0 PARL Nycticebus pygmaeus Pygmy Loris VU LKL Ptyas mucosus Common Ratsnake 0 PARL Macaca nemestrina Pig-tailed Macaque VU PARL Ophiophagus hannah King Cobra 0 PARL Macaca assamensis Assamese Macaque VU PARL Birds Macaca mulatta Rhesus Macaque NT PARL [Coturnix chinensis] [Blue-breasted Quail] 0 LKL Macaca arctoides Bear Macaque VU PARL Lophura diardi Siamese Fireback NT PARL Semnopithecus francoisi François's Langur (Hatinh Langur) EN PARL Rheinardia ocellata Crested Argus VU ARL hatinhensis [Pavo muticus] [Green Peafowl] VU ARL [Semnopithecus phayrei] [Phayre's Langur] 0 ARL Anser anser Greylag Goose 0 ARL Pygathrix nemaeus Douc EN ARL Cairina scutulata White-winged Duck EN ARL Hylobates leucogenys White-cheeked Crested Gibbon DD PARL Picus rabieri Red-collared Woodpecker NT 0 Cuon alpinus Dhole EN ARL Buceros bicornis Great Hornbill NT ARL Ursus thibetanus Asiatic Black Bear VU ARL Impacts Anorrhinus tickelli Brown Hornbill NT PARL Ursus malayanus Sun Bear DD ARL Aceros nipalensis Rufous-necked Hornbill VU ARL Mustela sibirica Siberian Weasel 0 LKL Aceros undulatus Wreathed Hornbill 0 ARL Mustela strigidorsa Back-striped Weasel VU LKL Alcedo hercules Blyth's Kingfisher NT PARL Arctonyx collaris Hog Badger 0 LKL Ketupa flavipes Tawny Fish Owl 0 LKL Melogale sp(p). Ferret badger sp(p). 0 LKL Treron sieboldii White-bellied Green Pigeon 0 LKL Lutra lutra &/or Lutrogale Eurasian and/or Smooth-coated Otter DD/VU (C)ARL perspicillata Ducula aenea Green Imperial Pigeon 0 ARL Aonyx cinerea Oriental Small-clawed Otter NT ARL Gallinago nemoricola Wood Snipe VU LKL Viverra megaspila Large-spotted Civet 0 PARL Vanellus duvaucelii River Lapwing 0 ARL Prionodon pardicolor Spotted Linsang 0 LKL Vanellus cinereus Grey-headed Lapwing 0 PARL [Arctictis binturong] [Binturong] 0 ARL Glareola lactea Small Pratincole 0 PARL [Hemigalus owstoni] [Owston's Civet] VU LKL Milvus migrans Black Kite 0 ARL [Felis chaus] [Jungle Cat] 0 ARL Ichthyophaga humilis Lesser Fish-Eagle NT ARL [Prionailurus viverrinus] [Fishing Cat] VU LKL [Ichthyophaga ichthyaetus] [Grey-headed Fish-Eagle] NT ARL Catopuma temminckii Asian Golden Cat VU LKL [Aquila clanga] [Greater Spotted Eagle] VU LKL Pardofelis marmorata Marbled Cat VU LKL [Aquila heliaca] [Imperial Eagle] VU LKL Pardofelis nebulosa Clouded Leopard c ARL Microhierax melanoleucos Pied Falconet 0 LKL Panthera pardus Leopard 0 ARL Ardea cinerea Grey Heron 0 PARL Panthera tigris Tiger EN ARL Ardea purpurea Purple Heron 0 PARL Elephas maximus Asian Elephant EN ARL Ciconia nigra Black Stork 0 ARL Rhinoceros sondaicus &/or Lesser One-horned Rhinoceros &/or CR CARL Pitta soror Blue-rumped Pitta 0 PARL Dicerorhinus sumatrensis Asian Two-horned Rhinoceros Urocissa whiteheadi White-winged Magpie 0 PARL Sus scrofa &/or Sus buc- Eurasian Wild Pig &/or Heude's Pig 0/DD PARL Cissa hypoleuca Indochinese Green Magpie 0 PARL culentus Terpsiphone atrocaudata Japanese Paradise-flycatcher NT LKL Cervus unicolor Sambar 0 PARL Cinclus pallasii Brown Dipper 0 PARL Muntiacus vuquangensis Large-antlered Muntjac DD Turdus dissimilis Black-breasted Thrush 0 LKL Muntiacus rooseveltorum &/ Roosevelts' Muntjac &/or Annamite DD LKL Turdus feae Grey-sided Thrush VU LKL or Muntiacus truongsonensis Muntjac [Niltava davidi] [Fujian Niltava] 0 PARL Bos gaurus Gaur VU ARL Bos javanicus Banteng EN ARL Ampeliceps coronatus Golden-crested Myna 0 PARL Naemorhedus sumatraensis Southern Serow VU PARL Sitta formosa Beautiful Nuthatch VU PARL Pseudoryx nghetinhensis Saola EN ARL Jabouilleia danjoui Short-tailed Scimitar Babbler NT PARL Ratufa bicolor Black Giant Squirrel 0 PARL Paradoxornis atrosuperciliaris Lesser Rufous-headed Parrotbill 0 LKL Callosciurus inornatus Inornate Squirrel VU LKL Emberiza aureola Yellow-breasted Bunting NT 0 Trogopterus / Hylopetes Small flying squirrel sp(p). 0/EN/0 LKL Mammals sp(p). Manis pentadactyla Chinese Pangolin NT ARL Rattus sikkimensis Sladen's Rat VU 0 Manis javanica Sunda Pangolin NT ARL Chiromyscus chiropus Fea's Tree Rat 0 LKL Cynocephalus variegatus Sunda Colugo 0 LKL Hystrix brachyura East Asian Porcupine VU 0 [Rhinolophus luctus] [Large Woolly Horseshoe Bat] 0 PARL Nesolagus timminsi Annamite Striped Rabbi DD LKL Notes: 1. Scientific and English-language names follow Duckworth et al. (1999) with amendments for bats and murids. 2. Global status follows the IUCN 2004 red list of threatened animals www.redlist.org. CR = Critically Endangered; EN = Endangered; VU = Vulnerable; NT = Near-threatened; DD = Data Deficient; 0 = least concern; n/a = not assessed. 3. National risk status follows Duckworth et al. (1999). ARL = At Risk in Lao PDR; PARL = Potentially At Risk in Lao PDR; CARL = Conditionally At Risk in Lao PDR (i.e. taxon is certainly At Risk if extant in Lao PDR); LKL = Little Known in Lao PDR. 4. Species not certainly known from the NNT and Nakai Plateau area are in square brackets. 5. GTS = Global Threat Status; NRS = National Risk Status Terrestrial Biodiversity 111 EAMP Main Text Impacts Figure 3.52: Forest types & land use within the Project area Table 3.53: Occurence and account of loss of habitats in the Project area Forest Type/Land Use Area of Habitat in the Percent Occurrence Area Lost or Degraded Percentage Loss to 3 Provinces1(ha) in the 3 due to the Project Loss Rank Provinces1 (ha) the Project Upper Dry Evergreen 447,505 7.4 16,820 3.8 5 Lower Dry Evergreen 11,878 0.2 0 0.0 ­ Upper Mixed Deciduous 1,480,886 24.6 19,119 1.3 11 Lower Mixed Deciduous 182,666 3.0 469 0.3 13 Dry Dipterocarp 716,417 11.9 5,511 0.8 12 Gallery Forest 4,091 0.1 286 7.0 3 Coniferous Forest 1,849 0.0 93 5.0 4 Mixed Broadleaved & Coniferous 100,838 1.7 27,208 27.0 1 Bamboo 20,111 0.3 0 0.0 ­ Ray 92,486 1.5 1,603 1.7 8 Savannah 79,092 1.3 0 0.0 ­ Scrub 126,746 2.1 216 1.6 14 Rice Paddy 544,133 9.0 8,716 1.6 9 Other Agriculture 6,103 0.1 174 2.9 6 Barren Land & Rock 211,072 3.5 165 0.1 15 Grassland 68,237 1.1 9,560 1.4 10 Swamp 45,955 0.8 4,702 10.2 2 Urban 10,788 0.2 302 2.8 7 Water 89,694 1.5 0 0.0 ­ Total 9,023,453 94,944 Note: 1. The three provinces are Khammouane, Bolikhamxai and Savannakhet 112 Terrestrial Biodiversity EAMP Main Text Plate 19: Nam Theun downstream of the dam showing mixed deciduous/ dry evergreen forest Plate 20: Nam Theun near Ban Thalang showing riverine/ bamboo forest grasslands, wetlands, agricultural areas (lowland and upland) and food or nutrients, as well as those which provide other essential temporarily deforested areas. These land cover types are described requirements for life, such as cover. The use and importance of a in Annex H and shown in Figure 3.52 and Plates 19-24. habitat can be determined using three general approaches: i) by As indicated in the Table 3.53, the total footprint of the Project will direct observation during the course of surveys or inventories; affect approximately 95,000 ha of land. During construction, this ii) through research involving more detailed observation and will increase to approximately 130,000 ha of land. The largest area experimentation; and iii) by intersecting known habitat affinities that will be impacted by the Project is the mixed broad-leaved and Impacts with the presence and condition of suitable habitat. The habitat coniferous forest (27% of this vegetation type in the three prov- affinities for the Project area are derived from WCS (1995, 1996, inces impacted by the Project). The second most affected area will be swamp (10%), and the third the gallery forest (7%). and 1997) and Duckworth et al. (1999). Generally, areas that are difficult to access and are rarely visited by knowledgeable scien- A number of surveys to determine the forest composition and to tists are ascribed a habitat value by inference using pre-existing record the structure of the tree canopy of the Nakai Plateau and adjoining NNT NBCA have been carried out (Burnside, 1996, information from the literature. The work carried out in the NNT IUCN, 1998, Margules Groome Poyry, 1996, WCS, 1995a, WCS, NBCA, Nam Theun ­ Phou Hin Poun Corridor and Nakai Plateau 1995b, WCS, 1996, Jarvie, 1997). However, there have been only by WCS, IUCN, DUDCP, and during the preparation of the EAMP, a few systematic surveys to determine the floral composition of employed relatively crude survey methodologies. Nevertheless, the main forest ecosystems, and therefore lile is known about for most part, these are the only objective observations available the regional and national conservation status of plant species of for the area. Surveys were carried out primarily using direct sight- Lao forests. Studies of wildlife distribution and NTFP use at the ings and indirect evidence (tracks, signs, etc.) and through inter- subsistence level by human communities tended to categorise views with local residents. These efforts have provided a basis for findings in terms of major forest communities and not in terms of the current knowledge base of the wildlife and plant associations habitat types. in the study areas. Nevertheless, they do not permit any measure Three species belonging to the Gymnospermae deserve special of variability, statistical confidence, or assessment of completeness. mention. Fokienia hodginsii is the only species of its genus and is Data continue to be intermiently collected and are expected to restricted to south China, Lao PDR and Vietnam. This species pre- progressively reveal additional and significant information about fers high elevation habitats and is not present on the Nakai Pla- the wildlife and their habitats. teau, but found in the upper reaches of the NNT NBCA, which according to Jarvie (1997) may be one of the last significant ref- uges for the species. However, this species is planted in northern Vietnam. Keetelaria evelyniana is endemic to the region, and occurs in Lao PDR and Vietnam (Jarvie, 1997). It occurs occasionally on the Nakai Plateau, but is locally common in the NNT NBCA and is grown on plantations in Vietnam. Pinus laeri is more widely distributed in the region. Most of the old-growth stands of Pinus laeri in the Project area have been impacted by logging, though substantial areas remain above the inundation zone at several sites on the northeast bank of the Nam Theun and in the southernmost sections of the Plateau. The habitat it provides, both on the Nakai Plateau and the NNT NBCA, highlights the need for special meas- ures directed towards its conservation. Habitat Affinities of Wildlife Wildlife habitat is that space where the animal lives over the sea- sons of a year. Habitat most oen has come to mean a physical location that contains both the resources that are exploited for Plate 21: Grassland typical of the Nakai Plateau Terrestrial Biodiversity 113 EAMP Main Text Plate 22: Wetlands on the Nakai Plateau Plate 23: Agricultural land on the Nakai Plateau Reservoir Area alluvial shelves lie along both sides of the Nam Theun, about 25 m The inundation area was evaluated by grouping habitats and above the water surface in January, and support a low 12 m-tall for- determining the potential wildlife species that could be present est containing abundant bamboo (Bambusa arundinacea, Oxytenan- there. Since extensive population estimates were not performed, it thera parvifolia) with small trees and shrubs. There is no distinctive is not possible to determine the viability of the populations for the riparian forest along the river except the bamboo. Below this area majority of species. In contrast to other fertile .at areas in Southeast the vegetation is patchy, comprising several grasses, a sedge and Asia, surveys by WCS (1995) found that the wildlife assemblage severalbroadleafherbspecies.Thesespeciesareprobablyconfined on the Nakai Plateau is sparsely populated. WCS (1996a) further to the clay-rich alluvium. Vegetation lines the riverbanks except noted that the mammal species recorded were at population levels where rock outcrops border the Nam Theun. Specific habitat types Impacts below that expected for intact forest tracts that have very low hunt- for the Nam Theun gorge were identified from the vegetation map, ing pressure and wildlife trade. The secondary, dry deciduous, augmented by partial coverage by aerial photography. The habi- evergreen and conifer forest habitats of the Nakai Plateau support tat types along the Nam Theun downstream from the Nakai Dam at least 210 bird species, and probably several dozen more The cur- are presented in Table 3.56. These habitats are typical of this area, rent significant loss of habitats on the Nakai Plateau is occurring although other habitats are also present in minor amounts. The in the pine forests, the riparian areas along the rivers and tributar- primary habitat of interest in Zone 4 is the river habitat. ies, and in the wetlands. Data from aerial photo analysis, Burnside (1996), and WCS (1995), points to a nearly complete loss of once Dividing Hills significant (>40% of the total area) Nakai Plateau non-flowing wet- The vegetation types and habitat elements of the dividing hills are lands. Although the riparian zone supports two key or indicator dominated by dry evergreen forest and to a lesser extent by mixed mammal species, the non-flowing wetland habitats, on the other deciduous forest. Other vegetation types and habitat elements hand, are remarkable for having lost their key or indicator mam- occurring in the dividing hills are outlined in Table 3.57 mals. The 13 key bird species and 4 key mammal species currently found in the wetland and riparian habitats do not include the Eld's Resettlement Area deer and the hog deer, which are presumably extirpated. Some of The proposed reselement site of approximately 21,000 ha is situ- these, as well as species which make significant use of wetlands, atedonthesouthwestsideoftheinundationarea,where17villages such as tiger, are candidates for an extensive conservation effort. will be relocated. The predominant vegetation type is broadleaf The inventory presented in Annex J of wildlife species recorded in the NNT NBCAand on the Nakai Plateau is based on information gathered by different workers to date. An exception is the Asian elephant, which is now reasonably well known following the stud- ies of Boonratana (2000) and Khounboline (2002). A summary of these observations is presented in Table 3.54 and 3.55. Nam Theun Downstream from the Nakai Dam The Nam Theun gorge downstream from the Nakai Dam is an area of open, dry evergreen forest bisected by the river. Here, the Nam Theun dramatically changes character from the slow, warm, 75 m- wide river of the Nakai Plateau to a 50 km-long 40m-wide series of alternating rapids and pools cuing through the sandstone and mudstone rock, with large boulders strewn within the river chan- nel. These areas provide considerable habitats for invertebrates that provide food for fish in the river. An occasional remnant, a quarter-hectarepoolthatisseparatedfromtheriverandfrequently dries during the dry season, is another feature of this diverse ripar- ian zone. The vegetation along the Nam Theun downstream from the dam site consists of good quality primary evergreen forest. Flat Plate 24: Degraded forest area on the Nakai Plateau 114 Terrestrial Biodiversity EAMP Main Text Table 3.54: Key bird species recorded from flowing and non-flowing wetlands on the Nakai Plateau. Key Bird Species Threat/ Risk status Wetlands association Status on Nakai Plateau International Red List White-winged Duck EN Flowing and non-flowing wetlands near trees Localised resident in 1994-1995; no subsequent information Blyth's Kingfisher NT Shaded forest streams Well distributed resident in suitable habitat Wood Snipe VU Shaded forest streams Winter visitor or passage migrant with few records; possibly much overlooked Lesser Fish-Eagle NT Shaded forest streams and rivers Resident, several pairs in 1994-1996; no subsequent information [Grey-headed Fish- NT Forest rivers and lakes on gentle terrain A few possible records perhaps stem from confusion with preceding species Eagle] [Greater Spotted VU Open areas especially around wetlands1 Non-breeding visitor; two records, not certainly identified to species Eagle] [Imperial Eagle] VU Open areas especially around wetlands1 One fly-over migrant, not certainly identified to species Lao At Risk List Greylag Goose ARL Large wetlands amid open areas One record only; certainly not common Tawny Fish Owl LKL Presumed flowing and non-flowing wetlands Occurs, presumed resident, but distribution and abundance unclear near trees River Lapwing ARL Wide rivers with extensive seasonally-exposed Well distributed breeder in suitable habitat in 1994-1996; no subsequent sedimentary features information Grey-headed PARL Short turf, bare mud and open marshy areas Fairly numerous winter visitor Lapwing in and around wetlands1 Small Pratincole PARL Very wide rivers with extensive seasonally-ex- One record only; certainly not common posed sand- or gravel bars or rock outcrops Impacts Black Kite ARL Open areas usually near wetlands1 Non-breeding visitor, now very scarce Grey Heron PARL Wide variety of open wetlands Scarce non-breeding visitor Purple Heron PARL Wide variety of secluded wetlands Scarce non-breeding visitor Black Stork ARL Mostly forest-stream ecotone, sometimes in Non-breeding visitor, now very scarce more open wetlands Notes: 1. Although individuals may be found outside wetlands with some regularity, species probably depends upon wetlands 2. Species predominantly of narrow forest streams are excluded See also Table 3.52 Table 3.55: Key mammal species recorded from flowing and non-flowing wetlands on the Nakai Plateau. Key Mammal Species Threat/ Risk status Wetlands association Status on Nakai Plateau International Red List Rhesus Macaque NT Riverine forest and scrub1 Common Eurasian and/or Smooth-coated Otter NT/VU Flowing and non-flowing wetlands Frequent Asian Small-clawed Otter NT Flowing and non-flowing wetlands Frequent [Fishing Cat] VU Habitat not well known1? Not certainly recorded but seems likely to occur Asian Elephant EN Flowing and non-flowing wetlands1 Viable population with predictable sea- sonal movements encompassing defined parts of the Plateau Lao At Risk List [Jungle Cat] ARL Grassland, scrub, open deciduous dipterocarp forest and Presumably occurred historically but may other non-closed-forest habitats with ready access to stand- now be locally extinct ing water1 Notes: 1. although individuals may be found outside wetlands with some regularity, species probably depends upon wetlands 2. insectivores, bats, murids and species from other orders that are predominantly of narrow forest streams are excluded See also Table 3.38 and coniferous forest, which covers 53% of the total area proposed Wetlands for reselement. Other vegetation types represented are dry ever- green (33%), secondary (7%), mixed deciduous (5%) and grassland Non-flowing wetlands of the Nakai Plateau include permanent (1%). Riverine fringe and riparian habitats are also present in the and seasonal freshwater lakes and ponds, marshes, and flooded area. The area is generally fragmented by human occupation and grasslands. Many of the wetlands exist as depressions up to one use. metre deep. Other wetlands are associated with grassland, bam- Terrestrial Biodiversity 115 EAMP Main Text Table 3.56: Habitat types of the Nam Theun Gorge Table 3.57: Habitat types for the dividing hills Vegetation Types/Habitat Elements Nam Theun Gorge Corridor Vegetation Types/Habitat Elements Dividing Hills (% of 41,705 Ha) (% of 32,560 Ha) Mixed deciduous 28 Mixed deciduous 15 Dry evergreen 66 Dry evergreen 51 Open/scrub 4 Open/scrub 35 Old field succession 1.5 Old field succession 1.5 Karst/limestone/outcrop 1.0 Karst/limestone/outcrop 1.0 Bamboo 3.0 Bamboo 3.0 Savannah grassland openings 1.0 Savannah grassland openings 1.0 Agriculture (upland paddy) 0.5 Agriculture (upland paddy) 0.5 Sandbars 0.2 Sandbars 0.2 boo, savannah and woodland vegetation in poorly drained areas. available and are provided below. The assessment of habitat type Many lakes and ponds on the Nakai Plateau are located in open and vegetation cover is ongoing and will be included in the next grasslands where livestock is maintained by the local villages. version of the EAMP. Claridge (1996) estimated that 50 km2 of seasonal wetlands exist on the entire Nakai Plateau, of which approximately 27.4 km2 will The chronology of biomass clearing on the Nakai Plateau between be inundated by the Nakai Reservoir. Wetland plant communities the years of 1973 and 2003 was assessed through the comparison in the Nakai Plateau change in species composition along a mois- of supervised classifications of MSS and TM satellite images for ture gradient. The most abundant types of vegetation associated the years 1973, 1989, 1996 and 2003. From 1973 to 1989 clearing with ephemeral wetlands include Panicum maximum and Eragros- and logging was concentrated largely within the inundation area, tis sp. in the weest areas, Eragrostis malayana in the drier areas, with some clearing apparent in the adjacent proposed reselement and Lasiandra sp. occurring in the relatively dry, outer fringe of the area (Figure 3.53). The proportion of clearing occurring outside the wetland areas. These wetlands are flooded to varying degrees for inundation zone in the period 1989 to 1996 was greater than that approximately 8-10 months of the year. Lasiandra sp. is the domi- inside the inundation zone. This coincides with a period of intense nant pioneer species in the waste ground that frequently borders logging activity from 1994 to 1998, of between 217,000 m3/yr and Impacts ephemeral wetlands. In permanent wetlands, Phragmites sp. is 441,000 m3/yr as indicated in the (BPKP) logging report of 1998- found in water up to approximately one metre in depth. Species 1999. extending out from the weest areas are Zoysia sp., Panicum maxi- Basedontheanalysis,thefollowingconclusionshavebeenreached mum, and Eragrostis sp. Vegetation in the driest, upper zone of the and are presented in Figures 3.54 and 3.55: i) from 1973-2003, for- permanent wetlands includes Eragrostis malayana, Zoysia matrella, est cover within the area of the Nakai Plateau decreased from 71% Centella asiatica, and Veronica undulatum. Submerged aquatic veg- to 60%; ii) for the same period, forest cover within the inundation etation includes Ceratophyllum demersum and Vallisneria spiralis in zone decreased from 61% to 48%; iii) 57% of all clearing in the shallow, sheltered, permanently inundated areas up to one metre period 1989-1996 occurred outside the inundation zone; and iv) deep. These species provide important refuge areas for cyprinid 43% of all clearing in the period 1996-2003 occurred outside the fish species and are a food source for other herbivorous fishes. Key inundation zone. bird species inhabiting the wetland areas are presented in Table 3.54. Key species of mammals that utilise the wetland habitat are It seems that the establishment of the NNT NBCA in 1993 (Berk- listed in Table 3.55. A variety of crabs, shrimps, frogs, snails, tor- müller et al. 1995), which covers the area to the north of the inun- toises will also be affected as the wetland habitats in which they dation area, has been largely ignored by the logging operators in are found become inundated. this period, with 57% of all clearing occurring outside the inunda- tion demarcation. Between 1989 and 1996 very lile of this change Dynamics of Habitat on the Nakai Plateau of forest cover can be aributed to shiing cultivation. The trend is Logging on the Nakai Plateau has been ongoing for the last 20 reversed in the following period, 1996-2003, when the boundary of years, primarily based on a concession by GOL to the state enter- the NNT NBCA was observed more stringently by logging opera- prise Bolisat Phatana Khet Phoudoy (BPKP). BPKP was allocated tors. The proportion of clearing occurring outside the inundation control over the Project's entire catchment. From the early 1980s zone decreased in the period from 1996 to 2003, but was still sig- BPKP developed and expanded timber harvest, transport and nificant (43%) (Aruna Technology, 2004). In the last years logging processing capacities. When the Project started to develop, BPKP activity has slowed considerably, as shown by visual reference of was directed by GOL to focus logging activities within the inun- 2000 SPOT multispectral data and the 2003 Landsat ETM data. The dation zone because the commercially valuable pine would not report of the World Bank logging survey team of 2002 noted that survive inundation. Volume of timber extracted expanded from no logging has occurred in this area since 2000. However, clearing earlier levels of 20,000-40,000 m3/yr to nearly 441,000 m3/yr in 1995 of limited scale within the NBCAarea still occurred in this period, (BPKP Logging Report, 1998-99). This rate of clearing would have but could not be aributed to logging or shiing cultivation. removed a total of 1.1 million m3 of commercial pine and hard- In addition to the current threats from logging, traditional collec- wood, representing virtually all of the commercial volume in the tion of NTFPs focusing on tree species, with emphasis on fragrant inundation area (Prosser, 1997). woodsand barks, may also be puing pressure on forest resources. To help further clarify the dynamics of the habitat loss, Aruna The availability and use of NTFPs is important during years of Technology (2004) conducted a detailed chronological assessment poor agricultural harvest. Bamboo, wood, raan and leaves are of biomass clearance, for both within and outside the reservoir used for construction and making implements. Traditional medi- area and to estimate the biomass currently present in the inunda- cal practitioners also rely exclusively on non-timber forest prod- tion area. The details for the chronology of biomass clearance are ucts for medicines. 116 Terrestrial Biodiversity EAMP Main Text Impacts Figure 3.53: Historical clearing on the Nakai Plateau, 1973-2003. Potential Impacts reach between the dam and the Nam Phao. Additional impacts Impacts to the terrestrial ecosystems on the Nakai Plateau will mayoccurdownstreamfromtheNamPhao,buttheseareexpected be fairly significant during the construction, operation of the to be minor. The primary impacts associated with the Nakai Dam reservoir and operation of the Power Station. They will be either and the 12 km reach downstream from the dam to the Nam Phao direct impacts related to the physical clearance, degradation or include the following: i) reduction in discharge and encroachment disturbance of ecosystems and/or indirect impacts resulting from of vegetation into the river channel; ii) periodic flooding of the area increased population and improved access. A full accounting of and possible scour of established vegetation; and iii) construction habitat loss as a result of the Project has been undertaken and has of the access road to the dam site and the dam itself. rationalised the adequacy of the conservation offset (Annex I). Because the amount of water discharged from the dam will be The Annex indicates that the lower mixed deciduous, dry dipte- reduced from an annual average of approximately 238 m3/s to an rocarp, and mixed broadleaf and coniferous habitats are not rep- annual average, taking into account the riparian release and spills, resented in the NNT NBCA, but this impact was not considered of just 16 m3/s, the potential for encroachment of vegetation into significant at provincial and national levels. The greater loss will the river channel is quite likely, in addition to a change of the river- be the environmental conditions of the river in this area, which bed vegetation. These encroachments could provide an additional constitutes a habitat for the white-winged duck. This species has source of food for mammals moving through the corridor between restrictive habitat preferences, and any habitat loss would be of the NNT NBCA and the Phou Hin Poun NBCA, and may create global significance, as discussed further in Annex I. new habitats for mammals, reptiles and amphibians that will be present in the pools associated with this reach of the river. How- The various impacts will be discussed relative to the following ever, during extremely wet years when the reservoir is filled and components: i) the Nakai Dam and the downstream Nam Theun; spill occurs to the Nam Theun, much of this vegetation will be ii)theNakaiReservoir;iii)theregulatingpondandtheDownstream scoured and the establishment of vegetation in the area will then Channel; iv) the Xe Bang Fai; and v) the Transmission Lines. resume. The nearby forest should not be affected. The reduced Nakai Dam & the Downstream Nam Theun flows in the Nam Theun from the Nakai Dam to the confluence with the Nam Phao will have an impact on terrestrial wildlife rely- Approximately 1,325 ha have been allocated for the construction of ing on fish in this stretch of the river.Anumber of terrestrial verte- the Nakai Dam and its access road. The construction of the Nakai brates depend upon the aquatic diversity and productivity of the Dam itself will only require 10-15 ha of clearance. Apart from the Nam Theun for food and shelter. The key and indicator species actual siting of the Nakai Dam, the main impacts to the terrestrial are diverse because the gorge has a diversity of habitats not seen system will occur downstream from the Nakai Dam in the 12 km in more uniform forested areas. Bird species of special concern Terrestrial Biodiversity 117 EAMP Main Text ment of vegetation into the channel downstream from the Theun Hinboun dam. Whilst severe impact on the vegetation is not con- sidered likely, the dependence of key and threatened species of mammals on the aquatic ecosystem is an important element of the Nam Kading's biodiversity. An analysis of the riparian release will be conducted in the near future and its findings incorporated into the EAMP. Nakai Reservoir The Nakai Reservoir operation will affect forests, woodlands, and land cover in the inundation zone, of which 57% has already been disturbed (Figure 3.55). Forest and woodland plant communities andlandusetypesontheNakaiPlateauconsistof13ecotypes, and form a mosaic of habitats that once was inhabited by an outstand- ing density and diversity of wildlife species. These species have come under increasing pressure over the last 30 years from sele- ment expansion, logging and hunting. The impacts associated with the initial filling of the Nakai Reser- voir are discussed in the construction and development impacts section. The reservoir will be refilled and drawn down on an annual basis. At full supply level, the reservoir will be at El 538 m, this will flood approximately 450 km2 of land area on the Nakai Plateau, approximately 40% of the total area of the Nakai Plateau. At FSL, all forests, savannah, grasslands and wetlands within this area will be inundated by the reservoir and their vegetation will be lost. During the drawdown period, the reservoir area could be reduced to a surface area of approximately 82 km2. This will create numerous wetland areas where fishing could occur as well as a Impacts vast area of mudflats, devoid of permanent terrestrial vegetation. It is expected that grasses and shrubs could become established along the margins of the reservoir area, with similar species those in the existing wetlands on the Nakai Plateau. The marginal areas of the reservoir could serve as a food source for livestock and potentially provide supplementary garden area for the Reselers. It is unknown how this potentially diverse range of habitatswillinfluencetheprevalenceofwildlife,particularlywhen so much of it will be either in or adjacent to a protected area. More commonly, some species such as shorebirds and shoreline breed- ers, ungulates, and others species could be negatively impacted Figure 3.54: Percentage change in land cover over time include the lesser fish-eagle and perhaps black stork. The mammal species include oers. The intact riparian habitat is important for the many species reaching highest densities in the forest--stream ecotone. It is currently not known whether the amount of prey in this section of the river will increase, remain static or decrease for birds such as the lesser fish-eagle and mammals such as oers. Downstream from the Nam Phao, the discharge in the Nam Theun will be increased as other tributaries discharge into the Nam Theun. However, the reduction in discharge, as a consequence of storage of water in the Nakai Reservoir,willcontinuedownstream. The reduction in discharge will increase the number of days that the Theun Hinboun reservoir will discharge its minimal riparian release of 5 m3/s. As a result, the discharge to the Nam Kading will be significantly reduced and there is a potential for encroach- Figure 3.55: Percentage of area cleared (1973-2003) 118 Terrestrial Biodiversity EAMP Main Text where large areas are exposed with extensive mudflats, when the Threatened Species reservoir is drawn down. Theareaofshorelinelioralzonewillvarybetweenapproximately Baseline Conditions 25 km2 at minimum operating level to approximately 200 km2 at Currently, there are 35 mammal species, 14 bird species, and 10 FSL.Themoistsoilswillharbourawidearrayofsemiaquaticinver- reptile species recorded in the NNT NBCA and Nakai Plateau tebrates such as molluscs and insects, as well as vertebrates such as (Table 3.52) that are classified as globally threatened, near-threat- snakes and turtles, thus providing a forage area for predatory ani- ened or data deficient according to the IUCN Red List of Threat- mals. The standing vegetation exposed at drawdown (mostly dead ened Animals (IUCN, 2004). In addition, there are 45 species com- trees) may provide cover for some wildlife species as well. How- ever, the degree to which this area will provide the resources lost prising 17 mammal species, 21 bird species, and seven reptile spe- by inundation of the original wetlands is difficult to determine. cies that are considered nationally at risk, potentially at risk, or It is recommended that both habitat requirements and alternative lile known in Lao PDR (Duckworth et al., 1999). Current threats, areas that can be utilised by vulnerable species be studied prior to such as hunting, to some species or to the overall biodiversity are inundation. Such mitigation measures are discussed in Chapter 6. well documented in a number of reports, but detailed knowledge The many vulnerable key species include the black stork (Ciconia on their distribution and intensity is still limited. nigra), Blyth's kingfisher (Alcedo hercules), lesser fish-eagle (Ichthy- Investigations into bats and rodents, in particular, are still limited, ophaga humilis), river lapwing (Vanellus duvaucelii), snipes (Gallingo with new species still being identified. For example, Francis et al., spp.), tawny fish-owl (Ketupa flavipes) and potentially congeners, (1996) have identified six range extensions (e.g. of bats previously and white-winged duck (Cairina scutulata). only believed to occur in peninsular Malaysia and Borneo) and Information gained from the study of habitat requirements and alternative areas can then be used to preserve or enhance areas containinghabitat orfoodresourcesthatwouldotherwisebeavail- able to the species of concern. The information can also be used to evaluate the likelihood that migrating birds might be able to find and utilise neighbouring wetland areas on the Nam Hinboun, Impacts Nam Thon and Xe Bang Fai, all less than 60 km away. However all these areas are presumably heavily hunted and thus are unlikely to be suitable under current conditions. In addition, 2,700 ha will be impacted by construction activities related to Road 8B as detailed in Annex I and will divide the cor- ridor area, possibly hindering movement and migrations of mam- mals and other wildlife from the NNT NBCA to the Phou Hin Poun NBCA. Thepresenceofthereservoirmaymakesomeareaseasiertoaccess, in particular for hunting, and therefore increase the vulnerability of the wildlife. For example, all of the dividing hills will become accessible if hunters camp for a night. Regulating Pond & Downstream Channel At FSL the regulating pond will inundate approximately 1.5 km2. The placement of the regulating pond in this area will require removal of vegetation and will impact a 4.6 km stretch of the Nam Kathang channel. All vegetation will be removed along the Down- stream Channel. The Downstream Channel will pass through rice paddies and secondary forests and will impact a small wetland downstream of the tunnel (Figure 3.56). Xe Bang Fai Impacts to the terrestrial resources along the Xe Bang Fai are pri- marily aributable to the increase of discharge in the river to an average of 220 m3/s and the associated loss of land, in particular riverine forests, along the river through erosion. The increased dis- charge, particularly during the dry season could also prevent the migration of mammals and other wildlife across the river. Transmission Lines The clearance of vegetation (4,650 ha) for construction and access roads required for routine maintenance of the easements are the main impacts associated with the transmission lines. The major- ity of the 500 kV transmission line traverses agriculture land, scrub and degraded forest. However, approximately 62 km passes throughlowlanddryevergreenforest,secondarysuccessionmixed deciduous and dry dipterocarp forest. The development of certain protocol will be required so as to minimise disturbance. Figure 3.56: Downstream channel alignment and habitat/land use types Terrestrial Biodiversity 119 EAMP Main Text at least two new species (Francis et al. 1999, Robinson et al. 2003) among 44 species of bats captured. Thus, surveys and censuses of 2003).Although lowlands (below El 200 m) provide optimum hab- much longer duration and intensity, covering all habitat types at itat, it is known to occur up to El 1,400 m, especially on plateaux all seasons and using a wide range of methods for lengthy periods supporting sluggish perennial rivers and pools (BirdLife Interna- are needed to obtain a picture of species present, their distribu- tional, 2003). The white-winged duck is very secretive, oen only tion and abundance. Wildlife species recorded or provisionally feeding at night, and although essentially sedentary, some birds recorded in the area, currently totaling over 100 mammals, over make short dry-season movements in response to low water lev- 400 birds, 38 reptiles, and 25 amphibians are listed in Annex J. els. In addition, the birds are relatively intolerant of human distur- There are various mammals and birds that are strictly or nearly bance and may abandon an area aer only a single contact with endemic to the Annamite mountains, some of which occur in the humans (Drilling, 2001), although this is evidently not so on the NNT NBCA and/or the Nakai Plateau, or can be expected to do Nakai Plateau. so.. These include François's langur, douc, white-cheeked crested Besides being threatened by hunting, the Nakai Plateau white gibbon, Owston's civet, saola, large-antlered muntjac, Annamite winged duck population will be impacted once the reservoir is muntjac, Heude's pig, Annamite striped rabbit, crested argus, inundated, and the loss of riparian habitat associated with inunda- short-tailed scimitar babbler. None of these is endemic to the Nam tion will likely result in their extirpation. However, given that the Theun basin and immediate surroundings. . In addition, other taxa ducks are intolerant to human intrusion and given that there're no very likely to have endemic representatives include the inverte- adequately protected sites within Lao PDR, neither translocation brates, reptiles and amphibians as well as plants. nor ex-situ conservation should be carried out. Nevertheless, alter- Management aention, including monitoring as indicators of the native measures must be drawn up to give the ducks an opportu- health of the wider environment, will be directed at least in part to nity to survive specific species. The most obvious of these is the Asian elephant, The Elephant Population because it is an umbrella species: by managing everything needed to retain elephants, many other species will persist. Other species There are reportedly two distinct sub-populations in the NNT can not readily be selected pending a baseline survey to assess NBCA. One is located in the northwestern part of the Nakai Pla- what is still present. White-winged Ducks are so rare that they teau, where the Nam Xot drains into the Plateau, and the other would merit specific aention, but it is not clear if there has been is located in the southeastern part of the Plateau where the Nam anyrecordaer1995.However,itislikelythatindicatorspeciesfor Theun drains into the Plateau (Boonratana, 2000). Based on dung directing management and monitoring aention should include density estimation, Boonratana (2000) gave a conservative estimate some water-forest ecotone species (fish-eagles, fish-owls, Blyth's of 94 individuals for the northwestern sub-population, but sug- Impacts kingfisher), some sensitive to hunting (hornbills, fish-eagles), and gested that the area could support up to 450 individuals during some that are both typical of open wetland edge and sensitive to the wet season. In a later study, Khounboline (2002) suggested that hunting (grey-headed lapwing, grey heron). If the reservoir creates the northwestern sub-population was likely to comprise about 120 suitable habitat for river lapwing, this would also be a good candi- individuals from six groups. date to consider. Careful thought should be given in the baseline The areas of concentration and the main travel routes of the north- survey to select monitoring indicators where enough data can be western sub-population during one wet season are primarily gathered to indicate trends with some statistical confidence. around Nong Pak Tok, Kouangten, Nam Gnalong, Ban Thalang, Nam Theun (between Ban Sopphaen and Kouangten), and at the The White-Winged Duck mineral licks Poung Phai, Poung Ta-ee, Tha-Xang and Poung Mak Apopulation of five to ten pairs of white-winged duck was identi- Pat. Boonratana (2000) summarised the seasonality in habitat use fied from the western end of the Nakai Plateau (WCS, 1995, Evans as follows: et al. 1997), which may not likely be viable on the long term. The · Use of the northwestern part of the plateau throughout the nearest known population to the Nakai Plateau is close to the year by the resident sub-population, and for some parts of the Cambodian border in the Xe Pian NBCAon the southern Bolovens year by the southeastern sub-population; Plateau. The area is a region of freshwater lakes, ponds, marshes · Use of the mineral licks throughout the year by the northwest- and seasonally flooded grassland in Aapeu Province, approxi- ern sub-population, and intermiently by the southeastern mately 130-150 km south southeast of the Nakai Plateau. Histori- sub-population; cally, the white-winged duck was widely distributed from north- · Wider, but more intensive use, of the northwestern part of the east India and Bangladesh, through Southeast Asia to Java and plateau during the wet season by both the resident and south- Sumatra, Indonesia. However, it has since undergone a dramatic eastern sub-populations; decline such that, in 1997, its global population was estimated at · High use of the Nam Theun riverine habitats (especially 450 individuals, and the total population for Lao PDR, Thailand, between Nam Gnalong and Nam Poungphai) during the peak Vietnam and Cambodia was estimated at 130 individuals (BirdLife wet season by both the resident and southeastern sub-popula- International, 2003). tions; It continues to decline throughout its range, largely aributable · Use of parts of the central forest area in Phou Hin Poun NBCA, to widespread hunting and lowland deforestation, compounded primarily at Kuan Xam, during the wet season; and locally by drainage and conversion of wetlands. The resultant · Higher use of bamboo patches for feeding rather than any small, fragmented populations are vulnerable to extinction from other habitats during the wet season. stochastic environmental events, loss of genetic variability, distur- Boonratana (2000) suggested that current observations were pri- bance, hunting and collection of eggs and chicks for food or pets. marily due to a higher availability of food in the northwestern part Hydropower development, inappropriate forest management, and of the Plateau during the wet season. In addition, frequent and pollution are more localised threats (BirdLife International, 2003). regular visits to the mineral licks clearly indicate the importance of The white-winged duck inhabits standing or slow flowing natu- these resources to the Asian elephant. Hence, the species distribu- ral and artificial wetlands, within or adjacent to evergreen, moist, tion and movement are also governed by the distribution of these deciduous or swamp forests, on which it depends for roosting and mineral sources (Olivier, 1978, Davies & Payne, 1982, Sukumar, nesting,usuallyintree-holes(Drilling,2001,BirdLifeInternational, 1989, Boonratana, 1997 & 2000, Khounboline, 2002). 120 Terrestrial Biodiversity EAMP Main Text Constituents of mineral licks usually differ for di.erent mineral- Afinal threat will be the improved accessibility of the NNT NBCA between licks, therefore resulting in a tendency for elephants to to residents of the rese.lement reselement areas and visitors, from visit as many mineral licks as possible (Lekagul & McMeely, 1997, the reservoir itself. The potential impacts to threatened and species Boonratana,2000, Khounboline, 2002). Furthermore, observations include the extirpation of the populations from the Nakai Plateau showed that mineral licks were visited more oen during the wet and to some extent from the NNT NBCA. season or aer rain, when water dissolving the nutrients allows them to be easily consumed (Lekagul & McMeely, 1997, Khounbo- Natural Habitats Accounting and Adequacy of line, 2002). Offsets In addition, peak rains most likely served as a trigger for different Interacting biophysical, climatic and anthropogenic factors have groups from both sub-populations to congregate along the Nam resulted in a complex mosaic of vegetation types in the Project Theun, apparently to socialise and mate (Boonratana 1997, 2000). area. A summary of the habitat types found in the Project area The elephant population in the Nakai Plateau is currently is presented in Table 3.58. Eleven habitat types are found in the threatened by poaching for ivory and by snares meant for other maximum Project footprint of 130,589 ha. The maximum Project large mammals (possibly leading to death from injury-caused footprint ploed on the maps does not represent the actual area to infections),and these threats will likely escalate with increasing be impacted, but rather the area within which the final construc- demands for wildlife and/or their products. They are also threat- tion zones will be located. In fact construction activities will prob- ened by habitat reduction due to agricultural encroachment, and ably impact less than 50% (in some case less than 10%) of the land from injuries caused by resident humans in their aempts to deter required under the Concession Agreement, called here "Project the elephants. Footprint". This is because the land requirement was defined at Human-elephant conflicts, as currently observed, apparently the stage of the Basic Design, when final location of Project infra- arise from habitat reduction, poaching, disturbance from past log- structure components was not finalized, and sufficient flexibility ging and related activities, and the elephants' acquired taste for required. The actual area to be directly impacted will be signifi- agricultural crops. Khounboline (2002) documented a number of cantly less (less than 50%) than the maximum Project footprint. encounters between humans and elephants that resulted in three However, as part of the project's precautionary approach, this persons killed and one seriously injured. Without mitigation maximum figure is used throughout this accounting document. Impacts measures, human-elephant conflicts will likely escalate once the The most dominant habitat in the Project footprint is disturbed/ reservoir fills in, primarily through competition for the remaining regenerating forest. The second most dominant is mixed broadleaf severely reduced and fragmented habitats. This will require proac- andconiferous,followedbyuppermixeddeciduousforest.Intotal, tive human intervention that includes making available suitable 109,620 ha of forest habitat is represented with disturbed/regener- habitats, ensuring abundant food supply, and avoiding the reset- ating forest making up 27% of this forested area. The remaining tlement of dislocated humans to known elephant ranges. 20,969 ha is made up from non-forest habitat types, of which agri- Likewise, it is expected that the reservoir will disrupt and restrict culture and swamp habitats cover an area of 11,995 ha (57%) and the movements and gene flow of the elephants. Over time how- 4,682 ha (22%) respectively. ever, the reservoir may not necessarily form a barrier. Boonratana (2000) estimated that the over water distances, along some of the Natural Habitats of High Conservation Significance known travel routes are less than 1.5 km at the FSL, and not more The coniferous forest on the Nakai Plateau, probably the most than400mattheMOL.Nevertheless,thisismerelyanassumption, extensive in Indochina, is dominated by Pinus laeri both in terms therefore appropriate mitigation measures must be developed and of stem density and biomass. P. laeri has been raised out of syn- implemented, whether the elephants will swim across parts of the onymy with Pinus merkusii. P. merkusii is found only in northern reservoir or not. Sumatra and the Philippines, and P. laeri is distributed in Viet- Potential Impacts nam, Lao PDR, Cambodia, Thailand and southern Myanmar; also in extreme southern China (Hainan Island), but possibly intro- Potentialsourcesofimpacttothethreatenedandendangeredatrisk duced there. It is found from sea level to El 900 m, usually in open, species are derived from the following sources: i) increased human savannah-like areas that are frequently burned by native peoples population on the Nakai Plateau resulting in increased hunting (de Laubenfels, 1988). P. laeri is listed as "threatened" by IUCN pressure and increased competition for the same resources; ii) but in the lowest category of "low risk". On the Nakai Plateau, the destruction of habitats for the threatened and endangered species; tree density of the coniferous pine forest averages 58.6 trees per and iii) increased human access to habitats where the threatened hectare, with trees exhibiting an average diameter at breast height and endangered species occur. The increased human population of 57.1 cm, indicating that this is old growth forest (Robichaud, on the Nakai Plateau will engender considerable hunting pressure 2002; Margules Groome Poyry 1996), probably about 60 years old. on wildlife and other natural resources. This is particularly true The species is adapted to fire and is a light demanding, heat and through the construction period and could likely continue through drought tolerant tree, growing well on sandy soils, such as those the operational period. The value of wildlife for the communities on the Nakai Plateau. P. laeri does not regenerate under its own of the Nakai Plateau is considerably greater than that of domestic canopy unless there is fire. It is therefore likely possible that their livestock. The former is considered a "free" resource or a source presence on the Nakai Plateau is linked to human-set fires for for additional income, and the laer is usually as maintained as the agriculture. Though low in plant diversity in comparison to other family's asset or kept for festive occasions. tropical forested ecosystems, this natural habitat is a valuable eco- Asecond source of impacts to the threatened and endangered spe- system which is poorly represented in Lao PDR. cies will be the destruction of habitats. To a large extent, habitats The riverine forest of the Nakai Plateau, which has yet to be eco- for theAsian elephants will be lost through the inundation of their logically or botanically characterised, is likely an ecosystem of mineral licks, forage areas and migration routes. Similarly, the high conservation significance. Similar natural habitats are found increased human population on the Nakai Plateau and inundation elsewhere in the Nam Theun catchment, along the Nam Choun of its habitat will likely cause the white-winged duck to disappear and Nam Seng, but these are unlikely to be as extensive as on the from the area. Plateau. Terrestrial Biodiversity 121 EAMP Main Text Table 3.58: Summary of thematic habitats found in the Project Footprint resinous wood) has been observed in the interior of the NBCA (based on FIPD, 2002) (Timmins and Evans, 1996). With increasing population and com- mercial demand, these products and other NTFPs, are likely to be FIPD Forest Thematic Habitats Area (ha) % of Project Foot- print Area subjected to unsustainable collection. Forest Unsustainable Agricultural Practice Disturbed/regenerating or unstocked 29,236 22.4 Long-term residents of the NBCA tend to use traditionally sus- forest tainable agricultural practices. However, it has been observed that Mixed broadleaf & coniferous forest 27,217 20.8 recent arrivals to the NBCA practice a short-cycle, unsustainable Upper mixed deciduous 21,688 16.6 form of farming (WCS, 1995). These swidden agriculture systems clear new land once their Dry Dipterocarp 14,430 11.0 present site is exhausted. This unsustainable agricultural practice, Upper dry evergreen 13,596 10.4 coupled with increasing population, is placing increased pressure Lower mixed deciduous 3,140 2.4 on NNT NBCAnatural resources. Gallery/riverine forest 254 0.2 On-going Land Development Activities on the Plateau Coniferous forest 59 0.0 Naturalhabitatsarecurrentlybeingconvertedasaresultofhuman Total all forest 109,620 83.8 activities. It is not possible to determine quantitatively what per- Non forest centage of this ongoing degradation of natural habitat could be perceived as having occurred in anticipation of the Project. Clear- General agriculture 11,995 9.2 ance may well have been a continuation of practices not related to Swamp 4,682 3.6 the Project; such as planned harvesting, collection by local com- Water 2,535 1.9 munities or uncontrolled commercial logging. Grassland 846 0.6 Project Impacts Rock 717 0.5 Project impacts on forest and forest biodiversity will occur dur- Urban 194 0.1 ing pre-construction, construction and operational phases, and are Total non forest 20,969 16.2 characterised as either direct or indirect impacts. Direct impacts Impacts are related to the clearance, degradation or disturbance of forest Grand Total 130,589 100.0 and forest biodiversity as a result of Project construction activi- ties and operations. Indirect impacts may result from increased Current Threats population and improved access to the forest, therefore generat- ing increased pressures on forest resources. With the exception of A variety of threats to the integrity of the natural habitats and the fragmentation and buffer zones, the following account on natural survival of its biodiversity currently exist and are identified below. habitat degradation focuses primarily on the direct impacts.Adis- These threats are independent of the Project and would probably cussion on indirect impacts is earlier in Chapter 3. also exist in a no-Project scenario. Accounting for Degradation & Conversion Logging The impacts within the immediate footprint are taken to be abso- P. laeri is a medium-value timber that has been extracted from lute land-take; where degradation or conversion resulting from areas both within and outside the reservoir inundation area, and vegetation removal, construction, inundation or suffcient distur- from the NBCA. This logging will continue ­ legally or illegally bance is considered as total degradation of the current habitat. ­ unless proper management and enforcement is instituted (Salter However, in reality, with the exception of the Nakai Reservoir, the et al, 1991 in Malaysian Environmental Consultants, 2003). GOL is Project footprint is larger than the actual long-term requirement making efforts to ensure that remaining stands outside the inunda- for construction and associated activities. The outstanding areas tion area are conserved by imposing a total ban. Current controls not required for construction may experience some disturbance appear to be effective, but the value and location of the remaining in terms of temporary vegetation clearance, water quality, ero- P. laeri stands puts them in jeopardy. sion, etc. For the most part, this disturbance will be temporary in Fokienia hodginsii is one of the most valuable timbers in Lao PDR nature and eventually, those impacted areas not required for direct and grows in areas of high-altitude near the Vietnam border (Tim- construction might, in some instances, be able to re-establish their mins and Evans, 1996). Logging within the NBCAtook place in the original natural habitat assemblage, although the duration will be mid-1990s, but appears to have ceased for now. In addition to the determined by the extent of disturbance. Therefore, the extent of direct impacts that logging has on the forest, construction of log- natural habitat degradation discussed below can be considered as ging roads facilitates access to critical natural habitats within the a worst case scenario and an over representation of actual extent NBCAand leads to increased hunting and extraction of resources. of impact. Commercial Extraction of Wildlife & Non-Timber Forest Calculations indicate that of the 130,589 ha of maximum Project Products footprint,62%willbenaturalhabitatandtheremaining38%willbe either non forest habitat, or disturbed/regenerating and unstocked The wildlife trade is currently a major drain on NNT NBCA forest. For specific habitat types, the ranked extent to be affected is resources (Robichaud, 2002), with a variety of mammal, birds and presented in Table 3.59. The major habitat degradation will be in reptiles being hunted for consumption or medicine. Vietnamese mixed broadleaved and coniferous (20.8%), disturbed/regenerat- traders regularly cross the border to hunt or purchase wildlife ing and unstocked (20.7%), and upper mixed deciduous (16.6%) from villagers. These cross-border poachers are intensively snar- natural habitats. Other habitats that will be significantly impacted ing wildlife up to 20 km inside the NNT NBCA(IUCN, 1999). Con- are dry dipterocarp, upper dry evergreen and rice paddy, repre- siderable extraction of raan and Aquilaria malaccensis (a fragrant senting between 9-11% of the maximum Project footprint. Details 122 Terrestrial Biodiversity EAMP Main Text Table 3.59: Thematic habitat types ranked by area to be affected by the Project Total Area within the Project (ha) Percentage of Respective Totals Rank FIPD Thematic Habitat Footprint Fragments Footprint + Fragments Footprint Fragments Footprint + Fragments 1 Mixed broadleaved & coniferous 26,972 246 27,217 27.5 0.8 20.8 2 Disturbed/ regenerating & unstocked forest 18,667 8,340 27,007 19.0 25.6 20.7 3 Upper mixed deciduous 18,450 3,239 21,689 18.8 9.9 16.6 4 Dry dipterocarp 5,225 9,204 14,429 5.3 28.3 11.0 5 Upper dry evergreen 9,508 4,088 13,596 9.7 12.6 10.4 6 Rice paddy 8,617 3,291 11,908 8.8 10.1 9.1 7 Swamp 4,596 86 4,682 4.7 0.3 3.6 8 Lower mixed deciduous 441 2,700 3,140 0.4 8.3 2.4 9 Water 2,535 0 2,535 2.6 0.0 1.9 10 Ray 1,365 95 1,460 1.4 0.3 1.1 11 Grassland 838 7 845 0.9 0.0 0.6 12 Scrub 152 615 767 0.2 1.9 0.6 13 Barren land & rock 63 654 716 0.1 2.0 0.5 14 Gallery/riverine forest 254 0 254 0.3 0.0 0.2 15 Urban 194 0 194 0.2 0.0 0.1 16 Other agriculture 88 0 88 0.1 0.0 0.1 17 Coniferous forest 59 0 59 0.1 0.0 0.0 Impacts 18 Unclassified 0 1 1 0.0 0.0 0.0 Totals 98,020 32,567 130,588 100 100 100 of the habitat areas to be disturbed by individual components of Fragmentation the Project are presented in Annex I and discussed below. In addition to the 98,020 ha of land potentially directly occupied, Reservoir 32,567 ha of land will be encircled by Project components. These The inundation of the 450 km2 Nakai reservoir will submerge veg- encircled habitats will experience indirect impacts resulting from etation below El 538 m, covering approximately 38% of the total fragmentation. This fragmentation accounts for 25% of the total Nakai Plateau. For the majority of these habitat types, their value 130,588 ha in the Project area (Table 3.61). The majority of this will be lost. The degradation of habitats on the Nakai Plateau due fragmentation will occur in the Reservoir Zone. In terms of area, toinundationofthereservoirisanunavoidableconsequenceofthe the predominant habitat types that will be impacted by fragmen- Project. However, not all habitats within the inundation area are tation are dry dipterocarp (9,204 ha) and disturbed/regenerating natural habitats ­ some have already been extensively disturbed and unstocked forest (8,340 ha), which respectively represent 28% by human activity. Approximately 15% of habitats on the Nakai and 26% of the total area to be fragmented. In terms of proportion Plateau have already been disturbed, of which 12.6% is within the fragmentation, for lower mixed deciduous and dry dipterocarp inundation area (Table 3.60). forest over 60% of the total impacted area is due to fragmentation. Therefore 13% of the area to be inundated by the Nakai Reservoir Approximately 30% of the total impacted area for upper dry ever- has already been disturbed. Natural habitats remaining in the green and disturbed/regenerating and unstocked forest is also due inundation area are mainly primary forest bordering slow-flow- to fragmentation. ing rivers, small lakes and wetlands. These natural habitats to be Though these habitats are not directly replaced or altered, the affected by inundation include mixed broadleaf and coniferous Project will result in fragmentation of this once contiguous habitat (28%), upper mixed deciduous (18%) and upper dry evergreen area. The constraints made by Project components on the biologi- (5%). An estimated 4,363 ha of swamp habitat will be affected cal exchange between fragments are not quantifiable, and there- to some degree, but depending on their location and the annual fore the significance of this fragmentation is unknown. Neverthe- drawdown cycle of the reservoir these habitats may not be perma- less, the severity of impact will be less than the total loss caused by nently lost. land-take for construction. Table 3.60: Extent of natural habitats & disturbed habitats within & outside of the inundation area Area Natural Habitat Natural Habitat % of Disturbed Areas Disturbed Area % Total Area (ha) Total % of Plateau Area (ha) Plateau (ha) of Plateau Reservoir (Plateau land take) 32,128 25.1 16,103 12.6 48,231 37.7 NNT NBCA Plateau 76,802 60.0 3,051 2.4 79,853 62.3 Total Plateau Area 108,930 85.0 19,154 15.0 128,084 100.0 Terrestrial Biodiversity 123 EAMP Main Text Table 3.61. Fragmentation of habitats caused by the Project Habitat Type Area Fragmented (ha) Total Area Impacted (ha) Fragmentation as a % of Total Area Barren land & rock 654 716 91.3 Lower mixed deciduous 2,700 3,140 86.0 Scrub 615 767 80.2 Dry dipterocarp 9,204 14,429 63.8 Disturbed/regenerating & unstocked forest 8,340 27,007 30.9 Upper dry evergreen 4,088 13,596 30.1 Rice paddy 3,291 11,908 27.6 Upper mixed deciduous 3,239 21,689 14.9 Ray 95 1,460 6.5 Swamp 86 4,682 1.8 Mixed broadleaved & coniferous 246 27,217 0.9 Grassland 7 845 0.8 Water 0 2,535 0.0 Gallery/riverine forest 0 254 0.0 Urban 0 194 0.0 Other agriculture 0 88 0.0 Coniferous forest 0 59 0.0 Total 32,567 130,588 24.9 Construction Downstream Channel: In the Gnommalat area, the construction of Impacts Reselement Area: The proposed reselement area of 18,732 ha the Downstream Channel will affect over 1,650 ha of land, which, will be situated on the southwest side of the reservoir. Figure 3.72 because of the greater presence of human population, predomi- (page 144) shows the 25 potential relocation sites and the habitat nately consists of rice paddy and agricultural land (48%). In terms types in the reselement area. The predominant natural habitats of forested natural habitats, 550 ha of dry dipterocarp will be in this area are mixed broadleaf and coniferous (55%), upper dry affected. Direct impact on forest in this area is therefore negligible. evergreen (22%) and upper mixed deciduous (18%). This impact includes the spoil areas as currently indicated. In total, only 750-1,000 ha will be degraded through conversion 115/500 kV Transmission Lines: Initially, the clearance of vegeta- to agricultural land and house plots. The proposed sites for the tion for the construction of both 115/500 kV Transmission Lines agricultural land and house plots have already been cleared or and their associated access tracks may affect up to 4,650 ha of land. degraded to varying degrees by past agricultural and logging activities. The majority of the remaining area indicated in the reset- This includes the section of the 115 kV Transmission Line from tlement area is allocated to sustainable forest management, and as Mahaxai to Thakhek, under the responsibility of EDL. The Trans- such the impact from the Project should be positive. mission Line alignments traverse rice paddy and agriculture land Nakai Dam: Approximately 1,325 ha has been allocated for the for 26% of the total area. These agricultural areas will not require construction of the Nakai Dam and its access road. The main sin- clearing, other than the area occupied for the construction of the gle natural habitat to be impacted for this construction will be in tower footprints. Other habitat types that will be affected by the upper dry evergreen forest (35%). However, much of the habitats construction of the Transmission Lines include dry dipterocarp directly adjacent to the Nakai Dam consist of unstocked or dis- (24%), disturbed/regenerating forest (19%) and unstocked for- turbed/regenerating forest (51%). The construction of the Nakai est (19%), which will require some degree of vegetation clearing. Dam itself will only require 10-15 ha of clearance, much of which There is a degree of flexibility in the precise final alignment, and will be in the inundation area aer the dam is closed. where possible the final route of the Transmission Lines will avoid Upgrade & Construction of Road 8B: On the Plateau, the upgrad- areas of major vegetation. ing of existing portions of Road 8B together with the construction During the operational phase, the Transmission Lines will impact of the new alignment will impact approximately 2,700 ha of habi- a substantially smaller area than indicated above. The impact will tats.Uppermixeddeciduous,mixedbroadleafandconiferous,and be limited to the actual tower footprints themselves and routine upper dry evergreen natural habitats represent 70% of this area. clearing of vegetation within the easements. An estimated 782 ha Power Station & Regulating Pond/Dam: Potentially, the construc- of habitat will be cleared for the Transmission Line tower foot- tion of the Power Station and regulating pond/dam will impact a prints and easement, over half of which will consist of lowland dry total of 900 ha. Much of the forest directly adjacent to the Power Station and regulating pond/dam construction areas is already dipterocarp forest (Table 3.62). degraded from past road construction and agriculture activities. These calculations are based on the assumption that no clearing This is reflected by the fact that over 60% of the area to be affected would be required in rice paddy and agricultural land, and mini- by the Power Station and regulating pond/dam comprises of either mal clearing would occur in unstocked and disturbed/regenerat- unstocked or disturbed/regenerating forest. ing forests. 124 Terrestrial Biodiversity EAMP Main Text Table 3.62: Degradation of natural habitats in Transmission Line Easements Easement Vegetation Type Segment 1 - 115/500 kV Line (ha) Segment 2 - 500 kV Line (ha) Segment 3 - 115 kV Line (ha) Total (ha) Lower dry evergreen forest 56 100 36 192 Lower mixed deciduous forest 42 100 12 154 Dry dipterocarp forest 126 240 16 382 Total 224 440 64 728 Buffer Zones ous forest (3.2%). Approximately 21,689 ha and 14,429 ha of upper No direct construction is planned to take place in the buffer zones sur- mixed deciduous and dry dipterocarp will be lost respectively, but rounding the Nam Kading and Xe Bang Fai. The primary impact associ- this represents only 1.5-2% of their total area in the three prov- ated with the Project will be the modification of hydrological regime. inces, and should not be considered as a significant degradation. Nam Kading: The buffer zone extends 270 m on either side of the The degradation of already altered land such as rice paddy, agri- Nam Kading and encompasses 11,377 ha of terrain. The major culture and urban habitat types will affect between 1.4 and 2.2% natural habitats present in the buffer zone include upper dry ever- of the provincial area but these are social rather than biodiversity green (25%) and upper mixed deciduous (11%) habitat, but the conservation issues, and are covered in the RAP. lesser valuable habitat types of unstocked and disturbed/regener- In summary, in terms of significance of the natural habitat lost the ated forest together represent almost 40% of the total buffer zone. natural habitats ranked 1-6 are those of concern for offset meas- The main concern in this zone is the reduction in flow aributed ures. However, the following should be considered when inter- not only to the Project but also to the operation of the Theun Hin- preting the significance of the natural habitat degradation: boun Hydroelectric Project. Whilst severe impact on the vegetation · The majority of the impact on the dry evergreen forest will not is not considered likely, the dependence of key and threatened spe- be land-take. This concerns the buffer area of the Nam Kading cies of mammals on the aquatic ecosystem is an important element. as it flows through the Nam Kading NBCA. Though inside the Impacts Xe Bang Fai: The Xe Bang Fai will experience almost a doubling maximum Project footprint area, the buffer is not expected to of the annual discharge. The subsequent increases in erosion will, experience significant impacts as a direct result of the Project; to some degree, impact the habitats surrounding the Xe Bang Fai. · The majority of gallery/riverine forest is located in the lower The buffer zone is similar in size to that of the Nam Kading, at reaches of the Xe Bang Fai. This is a naturally dynamic area 11,753 ha. However, due to the greater densities of human popula- changing shape over time, and so communities are able to tion in the area, the habitat types in the Xe Bang Fai buffer zone are adapt to periodic changes in river flow and exploit new habitat predominantly rice paddy and agricultural land (44%). Dry dipte- as it is made available. Increased dry season flow and erosion rocarp (21%) is a prominent natural habitat that could be affected created by the Project may favour early colonizers of the gal- in this zone. lery/riverine forest community; · Swamp conditions may develop on the sandy soils of the Pla- Significance of Natural Habitats to be Degraded or teau'sfloodedvalleys,currentlycoveredbymixedbroadleaved Converted and coniferous forest; and · The degradation of the lowland dry dipterocarp, lowland dry National Level of Significance evergreenandlowlandmixeddeciduousforestsmaynotbesig- At a national level of significance, the maximum Project footprint nificant in terms of conservation value. These lowland forests will impact only 0.6% of the national area. In terms of natural hab- exist in relatively densely populated areas and have been sub- itats, the maximum Project footprint will encompass 10% of the ject to much disturbance and exploitation. These forests have national area of swamps , 0.8% of lower mixed deciduous area, and long been used for timber and firewood collection, hunting, 0.5% of dry evergreen and coniferous forest (Table 3.63). Therefore and gathering of NTFPs ­ activities which have subsequently from a national perspective the degradation of natural habitat is reduced the complexity, diversity and density of the forests. insignificant, with the possible exception of swamps. The clearing of the forest for agriculture has le fragmented The comparison on a national level requires cautious interpreta- remnants that do not have the habitat values associated with tion due to discrepancies in data. The national level assessment similar vegetation communities in less populated areas. Taking was limited to using the 1992 FIPD data for the whole country. these factors into consideration, the proposed clearing in the lowland areas (for Power Station, Downstream Channel and Sub-National Level of Significance Transmission Lines) will not pose a significant threat to natural Terrestrial Natural Habitats: To minimise speculative accounting, habitats. details of the significance of the natural habitats to be degraded or Therefore,atthesub-nationallevelofsignificancethemajornatural converted at a sub-national level were generated for Bolikhamxay, habitat degradation will be in the mixed broadleaf and coniferous KhammouaneandSavannaketProvinces(Table3.63).Thetotalarea forest. This natural habitat class can be considered as a fire climax of 130,586 ha that will be degraded or fragmented by the Project that has created a mosaic of broadleaf and conifers, with conifers represents only 2.2% of the total area of these three provinces. The dominating in areas that have been recently burnt, but unable to greatest impact will be on mixed broadleaved and coniferous for- regenerate under their own canopy. In time they are replaced by est, with a total of 27,217 ha being potentially affected. This repre- broadleaf species. The conifers on the Plateau appear to have been sents 27% of the total habitat found in the three provinces. Swamp selectively logged, which would leave organic maer in the soils habitat (see footnote 1) degradation represents a 10% loss of the of the logged areas, and thus favour broadleaf regeneration. The original provincial extent. Other important natural habitats that species of this community are expected to be relatively quick to will register significant degradation at a sub-national level are gal- exploit the opportunity. As a result of the Project land-take how- lery/riverine forest (6.2%), dry evergreen forest (3%) and conifer- ever, the areas with the necessary environmental conditions that Terrestrial Biodiversity 125 EAMP Main Text Table 3.63: Habitat occurrence and degradation for Bolikhamxay, Khammouane and Savannaket Provinces Total Provinces Total National NT2 NT2 Project Area % of NT2 Foot- % of NT2 Habitat Degrada- Habitat Type Area (ha) Area (ha) Project + Fragmented print + Local Footprint + tion Rank in the 3 (FIPD 2002) (FIPD 1992) Area (ha) Areas (ha) Provinces Nation Provinces Mixed broadleaved & coniferous 100,838 0 26,972 27,217 27.0 na 1 Swamp 45,955 46,934 4,596 4,682 10.2 10.0 2 Gallery/riverine forest 4,091 0 254 254 6.2 na 3 Coniferous forest 1,849 12,333 59 59 3.2 0.5 4 Dry evergreen 459,383 2,566,847 9,508 13,596 3.0 0.5 5 Water 89,694 181,654 2,535 2,535 2.8 na 6 Rice paddy 544,133 923,020 8,617 11,908 2.2 1.3 7 Dry dipterocarp 716,417 1,444,411 5,225 14,429 2.0 1.0 8 Urban 10,788 20,064 194 194 1.8 1.0 9 Lower mixed deciduous 182,666 383,056 441 3,140 1.7 0.8 10 Ray 92,486 457,031 1,365 1,460 1.6 0.3 11 Upper mixed deciduous 1,480,886 7,203,863 18,450 21,689 1.5 0.3 12 Agricultural 6,128 113,204 88 88 1.4 0.1 13 Non-forest 2,056,982 8,643,727 19,657 28,619 1.4 0.3 14 Barren land & rock 211,072 217,082 63 716 0.3 0.3 15 Bamboo 20,111 835,979 0 0 na na 16 Forest plantation 0 1,230 0 0 na na Unclassed or cloud 1,547 0 0 0 na na Total 6,025,024 23,050,433 98,020 130,586 2.2 0.6 Impacts favour development will be reduced and these cannot be recreated life between the NNT NBCA and the PHP NBCA. Therefore the or substituted elsewhere. size of the fragmented area in the PHP ­ NNT corridor may be Aquatic Habitats:Atotal length of 673,135 m of river will be inun- less important than its location in a critical area between the NNT dated by the reservoir out of a total length of 2,340,919 m found on and PHP NBCAs. The biological function of the corridor area is the Nam Theun catchment above the Nakai Dam. This represents difficult to quantify, and it is hard to assign biological indicators 29% of the total length and should be considered as a significant to assess any changes in function. Concerns have been raised over degradation. Outside the inundation area, the change in hydrol- the movement of elephants and the small remnant population of ogy will alter the environmental equilibrium of river habitat. It is White-winged ducks (if still present) in the corridor. not possible at this stage to quantify the degradation of river habi- In addition to direct land-take, the effects of reduced river flow on tats that might occur through sluggish river sections, rapids, pools, aquatic communities needs also to be considered. The proposed sand banks, etc. reduction in flow in the Nam Theun below the dam site to a mini- Impacts on Protected Areas: It is anticipated that the Project will mum flow of 2 m3/s will have a significant impact on the aquatic directly impact approximately 1,181 ha of land within the PHP community, especially in the 12 km section of the Nam Theun ­ NNT Corridor. This represents only a 2.6% impact on a total cor- between the dam site and the confluence with the Nam Phao. Fur- ridor area of 45,123 ha. Figure 3.57 illustrates the areas of impact ther downstream, the effect on the flows of the Nam Kading in the within the PHP ­ NNT corridor. It should be pointed out that the Nam Kading NBCAwill also be influenced by the management of Project will not directly impact the NNT NBCA through construc- the Theun-Hinboun dam. tion activities: the only protected area to be directly impacted will be the PHP ­ NNT Corridor. Importance of Natural Habitat Degradation to Species Overall an estimated 10,567 ha of protected area will affected by Assuming the principles of the planned salvage logging are fol- Project activities. The majority of this area is not subject to physical lowed, when the water level in the reservoir rises, few if any ter- land-take. Over 85% of this total area will experience only indirect restrial animals will be either forced out of their natural habitat or impacts, which include: trapped in isolated pockets. Natural habitat degradation will have · The areas surrounded by fragmentation caused by Project an impact on biodiversity at the community, species and genetic roads and facilities in the PHP ­ NNT corridor on the Plateau levels. ­ 4,317 ha or 40.9%; and Using the habitat criteria for species whose niche has a river type · River buffer around the Nam Theun and Nam Kading as it component, the following species will be affected: flows through the Nam Kading NBCA and the PHP ­ NNT · The White-winged duck will experience degradation of the corridor ­ 5,062 ha or 47.9%. existing habitat on the Nakai Plateau (but new suitable habi- The significance of impacts on the protected areas needs to go tat is expected to be formed in the Special Conservation Areas beyond quantifying immediate land-take alone. The issues of north of the reservoir); and concern for the NNT NBCA and neighbouring protected areas · The fish eagles, the Crested and Blyth's Kingfisher, and the include the effect on function at a regional level, and at the local River lapwing, have ranges that cover higher elevations. Some level the impact on biological functioning and movement of wild- 30% of their habitat will be degraded. 126 Terrestrial Biodiversity EAMP Main Text Elephants TheAsian elephant has been identified as a species of special inter- est to the Project, as natural habitat degradation will be extensive for the species, and there exists a potential for increased conflict with the human population. It is the key large mammal on the Plateau, and hence the conservation of this species can ensure the conservation of other species using the same natural habitats. Current threats are from hunting and natural habitat degradation. The main Project impacts on the elephant population include fur- ther degradation of natural habitats (including critical resources such as mineral licks), increased access for poachers, disruption of movement paerns, and increased conflicts with the resident human population (which can lead to injury and death to both humans and elephants). Elephants in the northern end of the Pla- teau range into the NNT NBCA and the PHP NBCA. Past experi- ence with elephants in reservoir areas indicates that inundation may not alter habitual movements significantly, but the risk still remains that new routes may be adopted. Creation of Habitats The Project will create a host of habitats, primarily in the inunda- tion zone of the Nakai Reservoir. Potentially, the habitats that will be created include: Figure 3.57: Habitat areas impacted within the NNT-PHP Corridor. · Lacustrine habitat of the reservoir; · Islandhabitats withvariousforesttypesformedby the inunda- tion; Impacts Inundated Areas & Wildlife Movements · Ephemeral and permanent swamps adjacent to the reservoir; · Smaller lakes, pools and sluggish streams created by the back The inundation area of the Nakai Reservoir will impact both nat- water of the reservoir; and ural habitats and wildlife. Some species that habitually cross the · Mudflats and seasonal grasslands created by the annual reser- Plateau may continue to do so aer inundation. During periods voir drawdown. when the reservoir water level is at FSL, movement will be limited The extent and connectivity of these permanent and ephemeral to flying and swimming species. The banks are steep in this area, habitats will depend on both seasonal variations in rainfall and and there will be lile change to the surface area of the islands as seasonal dynamics of inundation resulting from the operation of the water changes depth. Species able to swim, such as elephants, the Project. On an annual basis, these habitats will undergo both will be able to island hop and swim across the corridor. In periods increases and decreases in size. There is a degree of scientific when the reservoir water level is low, constraints on movement uncertainty aached to the creation and characterisation of these may possibly be similar to those experienced before the Project. habitats as they have a broad possibility of becoming functional In general, the terrestrial species that use the river corridor to habitats supporting a wide array of both plant and animal diver- travel will likely find the reservoir an impediment to their move- sity. The habitats created by the Project will take time to stabilize ments. However, the relatively shallow slopes of the dividing hills and support communities. Fluctuations in niche volume created adjacent to the reservoir are not expected to be a major constraint by seasonal changes in reservoir level could cause a decrease in the population of some species that aempt to adapt to the new to north-west/south-east movement. conditions. It would therefore be premature to speculate on the White-winged Duck possible contribution of these habitats created by the Project in supporting certain communities or populations of conservation The reported five to ten remaining pairs of White-winged duck importance. The enclaves that will be created on the northeast side select natural habitats below 600m (WCS, 1995). The length of of the reservoir have the potential to form important habitats, such river degradation below 600 m due to inundation totals 664,542 m. as wetlands and small lakes, for fish spawning and feeding and Comparing this degradation to that remaining in the NNT NBCA for other important species associated with these types of habitat. shows a shortfall of 27,216 m. Comparing the same degradation to The potential of the northern part of the reservoir and the north- just the area within the NNT NBCA, the shortfall rises to 370,535 ern embayments to become appropriate/acceptable habitats for the m. This implies that the available natural habitat for the White- ducks has already been mentioned. The feasibility of creating slow- winged duck will decline to 30% of the current area when the res- flowing artificial wetlands close to the existing White-winged duck ervoirisinundated,leavingonlysuitablehabitatinabandbetween habitats but above the inundation zone, is worthy of investigation. El 538 to 600m. However, new suitable habitat should form in the Area to be Protected by the Project embayments and Thousand Islands parts of the reservoir. Considering the low population numbers of the White-winged The principle offset for degradation of natural habitat by the Project is the financial assistance and management support for the duck, this local degradation of its fundamental niche area may not conservation of the 338,718 ha NNT NBCAand adjacent protected be significant. In terms of resource needs, the reduced area may areas. This management is under the control of the Nam Theun be sufficient to support the current population. There is however 2 Watershed Management and Protection Authority. To assist the an issue is the viability of the remaining population (they have operations of the WMPA, a management framework and detailed not been seen for nearly ten years) and preservation of the genetic operational plan, the SEMFOP, has been developed. The frame- diversity they contribute to the world population. work and plan should ensure the long term sustainable manage- Terrestrial Biodiversity 127 EAMP Main Text short term prevent local extinction. Without some form of man- agement presence to protect the NNT NBCA from unsustainable human use and natural habitat degradation, biological diversity in all the region's protected areas will experience decline. The current threats to the NNT NBCA, highlighted earlier in this annex, will continue unless adequate resources can be made avail- able for its management and protection. Figure 3.59 shows that northern and central parts of the NNT NBCAhave been disturbed, while the southern parts appear to have experienced relatively lit- tle human activity. Therefore it is imperative that successful man- agement is implemented to prevent any further degradation of this globally significant area. Adequacy on a Habitat Level: As Table 3.64 shows, with few exceptions, the areas of analogous forest and habitat type offset in the NNT NBCA significantly exceed those that will be lost as a result of the Project. In particular, the natural habitat types of dry evergreen, upper mixed deciduous, coniferous and gallery/riverine forest are fully offset by the conservation of the NNT NBCA. However, not all natural habitat types will be represented in the offset area, and of those that are, their representation may not be equivalent to the Figure 3.58: Regional Protected Areas. area of impact in the maximum Project footprint. These exceptions include swamp habitats, mixed broadleaf & coniferous, lower ment of the area. The Project will provide initial funding of US$ mixed deciduous and dry dipterocarp forest. 6.6 million for activities prior to the start of Project operations, and In terms of aquatic habitats, the NNT NBCA will protect 859 km US$ 1 million for each year of the operating phase thereaer. GOL of river with slope < 5°, compared to the 622 km of degradation currently has few resourcestodevote tothe conservation andman- due to the inundation of the reservoir. This conservation of similar Impacts agement of conservation areas. habitat can be considered as an adequate offset for the degradation of aquatic habitats due to the reservoir. Adequacy of Offsets It has already been suggested above that using the uplands area of Regional & Global Significance of the NNT NBCA: The northern the NNT NBCAas an offset for impacts to lowland natural habitat Annamite Mountains are of outstanding importance in terms of typesmeansthatenvironmentalimpactattheregionalandnational global and regional biodiversity. In recent years, two endemic spe- levels shall be minimal. There is potentially a significant shortfall ciesofungulateshavebeendiscovered­thesaola(Pseudoryxnghet- of mixed broadleaf and coniferous forest in the NNT NBCA offset inhensis) and the large-antlered muntjac (Muntiacus vuquangensis), compared to the area lost from inundation. However, despite con- and Heude's pig (Sus bucculentus), long thought to be extinct, has cern about the potential loss of diversity of conifers at the genetic been rediscovered in the area (Duckworth et al., 1999). Several spe- level, the degradation of the forest community and species popu- cies of fish, mostly new to science, were considered to be endemic lation is not the main issue. The greater degradation will be the to the Nakai Plateau ­ e.g. Scaphognathops theunensis and Tor ater environmental conditions of the river in this area that constitutes ­ but now are known to inhabit headwaters of the Nam Theun a natural habitat for a number of species, including potentially catchment outside the zone of direct impact. the White-winged duck. This species, if its continued presence is The NNT NBCA, within these northern Annamite Mountains, is confirmed on the Nakai Plateau, has restricted habitat preferences, the largest protected area in Lao PDR and is considered one of the and any habitat degradation would be of global significance. most important protected areas in Asia (Robichaud, 2002) and of Neither lower mixed deciduous nor dry dipterocarp natural habi- global significance (MacKinnon, 1997). On a regional level, the tats are represented in the NNT NBCA, and therefore the offset NNT NBCAhas the country's most important forest cover in terms cannot be seen as adequate for these habitat types. However, at of extent and quality (Berkmuller et al., 1995), and is ranked the a national and provincial level the impact on both these natural highest overall in terms of threatened bird and mammal species habitats is not perceived as significant. (Ling, 1999). The decision on whether the degradation of one natural habitat The NNT NBCAis contiguous with the Vu Quang Nature Reserve area can be compensated by the conservation management of in Vietnam. The PHP ­ NNT and NNT ­ HNN corridors link NNT another is subjective and depends on the values assigned to the NBCA with Hin Nam Nor NBCA and Phou Hin Poun NBCA natural habitat degraded or protected. The fact that the security respectively (Figure 3.58). of the NNT NBCA has been made dependent on the Project is not The proposed northern extension of the NNT would link it with a relevant issue. What is relevant is the possible loss of biological the proposed Pu Mat Reserve in Vietnam. As a result of its central diversity through non-effective management of the NNT NBCAin location, the NNT NBCA is considered a linchpin for protected a no-Project scenario. The security of the NNT NBCA is of critical area systems in the region. The NNT NBCAacts as a core through importance for regional as well as global conservation. Thus any which genetic material is transported between the surrounding degradation of individual natural habitat elsewhere could be out- protected areas.Apart from the value of the varied natural habitats weighedbythepotentialgainsinimprovedregionallyandglobally for species richness, the biological functions of the NNT area are important biological communities in the NNT NBCA. To use the assumed to regulate populations and species distribution. From White-winged duck as an example, the degradation of its existing a management point of view, these biological functions provide habitat may be potentially severe, but as it is believed that there is a regulating mechanism to sustain biological diversity, and in the currently only a small population, this may not be significant. 128 Terrestrial Biodiversity EAMP Main Text Impacts Figure 3.59: Historical clearing 1973-present. All remaining individuals could be accommodated in the area Conclusion available and if hunting and habitat disturbance (for this and other species) can be minimised, then it is possible that the area of suit- Natural habitats in the Project area are currently being converted able habitat can be increased even though the absolute size of the as a result of human activities. From 1973-2003, forest cover within existing habitat declines. In this way, effective land resource man- the area of the Nakai Plateau decreased by 11% to 60% cover, and agement can more than offset degradation. forest cover within the inundation zone decreased by 13% to 48%. Table 3.64 Adequacy of the NNT NBCA as an offset for Project impacts (ha) Habitat Type Maximum Project Maximum Project Footprint NNT NBCA % of Immediate Area % of Immediate & Fragmented Footprint + Fragmentation Offset in NNT NBCA Areas Offset in NNT NBCA Dry evergreen 9,508 13,596 189,219 100 100 Upper mixed deciduous 18,450 21,689 48,513 100 100 Gallery/riverine forest 254 254 934 100 100 Coniferous forest 59 59 51,262 100 100 Non-forest 19,657 28,619 43,813 100 100 Ray 1,365 1,460 2,124 100 100 Agricultural 88 88 1,052 100 100 Urban 194 194 63 32.5 32.5 Rice paddy 8,617 11,908 1,507 17.5 12.7 Swamp 4,596 4,682 181 3.9 3.9 Mixed broadleaved & 26,972 27,217 45 0.2 0.2 coniferous Lower mixed deciduous 441 3,140 0 0 0 Dry dipterocarp 5,225 14,429 0 0 0 Barren land & rock 63 716 0 0 0 Water 2,535 2,535 0 0 0 Total 98,020 130,586 338,718 Terrestrial Biodiversity 129 EAMP Main Text Of 130,589 ha of maximum Project footprint that could poten- GOL has recently adopted the protected area competence stand- tially be affected, 62% will be natural habitat and the remaining ards developed by the ASEAN Regional Centre for Biodiversity 38% will be either non-forest habitat, disturbed/regenerating or Conservation. These will serve as important guidelines in devel- unstocked forest. The major habitat degradation will be in mixed oping the capacity of WMPA personnel. A training needs assess- broadleaved and coniferous (20.8%), disturbed/regenerating and ment, intensive capacity development and on-the-job training unstocked (20.7%) and upper mixed deciduous (16.6%) natural programmes would be required. The management would need to habitats. Other habitats that will be significantly impacted are dry develop a proactive, highly organised and well co-ordinate patrol- dipterocarp, upper dry evergreen and rice paddy, representing 9- ling plan, possibly with additional human resources from the dis- 11% of the maximum Project footprint. An estimated 10,567 ha of trict military and police, and the local communities. protected area will be affected by Project activities. The majority Zonation will be required, and locations of work camps and the (85%) of this area is not subject to physical land-take but indirect carrying capacity of the campsites will be determined to minimise impacts of fragmentation or river buffer. impacts on wildlife and their habitats. To minimise impact on the From a national level perspective, the degradation of natural habi- Plateau, the majority of the proposed work camps are located in tat is insignificant, with the exception of swamps (see footnote 1). the lowland Gnommalat plain, with possibly a single work camp The Project will encompass 10% of the national swamp area. From located northeast of the Nakai Dam, adjacent to Road 8b, to pro- a sub-national perspective the greatest impact will be on mixed vide workers for dam construction (the location of work camps broadleaved and coniferous forest and swamps, with 27% and is given in Figure 2.18). Waste disposal facilities will need to be 10% of the total habitat found in the three provinces potentially developed for both human waste and garbage, to prevent trans- impacted. Other natural habitats that will register significant deg- mission of diseases to wildlife and liering. radation at a sub-national level are gallery/riverine forest (6.2%), dry evergreen forest (3%) and coniferous forest (3.2%). Minimisation of Impacts During Impoundment The areas of habitat types offset in the NNT NBCA significantly During the construction phase, prior to impoundment of the Nakai exceed those that would be degraded as a result of the Project. Reservoir, a wildlife specialist will analyse known and potential Dry evergreen, upper mixed deciduous, coniferous and gallery, threats to animal populations in the Nakai Reservoir area, and pre- gallery/riverine forests are fully offset by the conservation of the pare a detailed plan to minimise impacts on animal populations NNT NBCA. Lower mixed deciduous and dry dipterocarp natural when the Nakai Reservoir is formed. While it is recognised that habitats are not adequately offset by the conservation of the NNT the NNT NBCA is a large area of protected habitats, some animal NBCA. However, the impact on these natural habitats is not per- populations may already occupy many of the suitable habitats. In addition, problems may arise in relocating some species from the Impacts ceived as significant at either the national or provincial level. Nakai Plateau because habitats in the NNT NBCAare significantly Mitigation Measures & Enhancements different. Although some populations of threatened species will The following are recommendations for further evaluation of the likely stabilise once hunting is managed, habitat suitability in the species, and potential measures for improving their habitats and NNT NBCA will nevertheless need to be evaluated prior to filling managing the populations.. the Nakai Reservoir, in order to identify suitable habitats for these species. Monitoring for Wildlife In addition, an important precautionary measure to undertake Although not exhaustive, basic baseline information on the Nakai prior inundation is with respect to human reselement. Resele- Plateau wildlife is available from various studies (Delacour 1929, ment of affected villages should neither be anywhere near the ele- Francis et al. 1996, WCS, 1995b, 1996a, Timmins and Evans 1996, phants' known range nor near any critical wildlife habitats (feed- Evans et al. 1997, 2000, Evans and Timmins 1998, Duckworth et al. ing patches, mineral licks, and leks). The former is to avoid the 1998a, 1998b, Thewlis et al. 1998, Boonratana, 2000, Khounboline, likelihood of displaced elephants seeking food in or near human 2002) that could be used to initiate a monitoring programme. Fur- selements and/or agricultural lands, therefore effectively pre- thermore, the programme needs only to focus on certain indica- venting escalation of human-elephant conflicts. tor species (e.g. elephants, primates, hornbills) to monitor wildlife When the reservoir fills, wildlife will be drowned, displaced or and habitats, and to focus on certain human activities to monitor stranded on the islands formed. Gradual filling of the reservoir impacts on wildlife and habitats. Detection of as-yet unrecorded to resemble natural floods may eventually cause many animals to species and confirmation or refutation of hitherto provisionally move to higher ground. However, specialists will need to be iden- recorded species can be simultaneously carried out with the moni- tified at least a year before the planned inundation, and a wild- toring programme. More species would likely be added to the list life rescue plan will have to be established and fully operational of monitoring indicators once monitoring has been continuously at least six months before the planned inundation. This includes carried out for several years. establishing and training teams, identifying viable and potentially A rigorous monitoring programme would obtain data that could viable islands, establishing holding areas, acquiring appropriate detect actual changes and trends in populations, and data that equipment and drugs, and identifying release sites.As new islands could be statistically tested. Rigorous methods would produce will be formed each year, the training component should include realistic census data and density estimates, important for conser- the training of locals to manage the operations as and when the vation and management. However, they would require very large needs arise. time investments by competent human resources to monitor the In addition, animals stranded on islands will be vulnerable to ecological parameters and to manage the data. poachers. Hence, there needs to be intensive and extensive patrol- Minimisation of Impacts During Construction ling of the reservoir islands, and this will likely require additional human resources and equipment (speedboats, electric outboards, To minimise the impacts of work camps related to the construction radios, and spotlights) for the first few years. Patrolling before of the dam, a priority will be to ensure that the HCCEMMPs are inundation would comprise a combination of boat, o.-road bike, well advanced before construction begins. In addition, WMPAper- and foot patrols. Aer inundation, focus of patrolling would be sonnel must acquire the relevant competence, in particular, patrol- on the use of boats, and occasionally on foot for some of the larger ling must be in place. islands. 130 Terrestrial Biodiversity EAMP Main Text The proposed investigation will focus on: including the assessments of: i) population size and distribu- · Potential methods for early mitigation to encourage animals to tion; ii) migratory paerns; iii) current suitability of habitats and move before filling of the reservoir; resource use for elephants; and iv) how future habitat suitability · Developing an understanding of how the Nakai Reservoir will will change as a result of inundation. fill and how and where islands will form; Boonratana (2000) has made recommendations, which included: · Comparing data with past and current wildlife surveys; · Carrying out a study on the ecological importance of mineral · The need for communication and co-ordination between licks to the elephants and other herbivores. This study was NTPC, GOL, WMPA, district and provincial authorities and conducted by Khounboline (2002), who examined the com- villagers; position of mineral licks in the Nakai Plateau and provided · Development of measures to manage organised hunting par- some insight into the nutritional value of mineral licks to the ties; and elephants, and their influence on the elephants'ecology, behav- · Identification of methods for enforcement activities to mini- iour and ranging paerns; and mise hunting and wildlife trade. · Carrying out a long-term study on the ecology and behaviour In addition to these pre-emptive measures, a decision regarding of the Asian elephant on the Nakai Plateau, for at least three physical rescue of animals stranded on the islands will include: continuous years before the reservoir fills and for at least three · Identification of competent specialists to lead and manage the continuous years aer that. operation; Thus, efforts must geared towards maintaining or achieving high · Identification and training of field teams involved in the rescue quality habitat, which is characterised by: i) proximity to water, operation; foraging areas, and mineral licks; ii) availability of a mosaic of · Selection of equipment and methods for wildlife capture, habitat types; iii) availability of preferred food plants; iv) low lev- transport and release; els of habitat fragmentation and alienation; v) contiguous areas of · Fulfilling specific requirements for equipment and resources habitat sufficiently large to support a viable population; and vi) for rescue efforts; retention of seasonal movement corridors. · Establishment of criteria for euthanasia of injured animals; In addition, Khounboline (2002) suggested testing known meth- · Establishment of animal handling procedures; ods (detection methods, passive deterrents, and active deterrents) Impacts · Development of a programme schedule; and for protecting crops from elephant raids, with the aim of develop- · Necessary training for field teams to prevent hunting of vul- ing practical tools that can be used by the local rural communities. nerable animals; This study will be incorporated into the elephant programme to Management of Key Wildlife Species help reduce the impact on elephant-human conflict once the res- As mentioned above, about 40% of the plateau will be inundated ervoir fills. and of the remaining area, about 50% of the forests are in rela- The mitigation measures to conserve elephant populations will tively good condition. There may be sufficient habitat to maintain need to take into account the population dynamics and the exten- viable populations of most of the Nakai Plateau fauna. However, siveuseofresourcesontheNakaiPlateau.Inaddition,thepotential some wide-ranging predators (e.g. tiger) are territorial and they for increased interactions with human populations must be incor- may require an area the size of the reservoir just to maintain a few porated into the management plan. In terms of mitigation meas- breeding males. Other animals such as elephants move seasonally ures against the impacts of habitat loss, escalated human-elephant between widely dispersed resources or ephemeral resources like conflict and other related issues arising primarily through creation bamboo,andthereforerequirespecialmitigationandmanagement of the reservoir, Boonratana (2000) proposed the following: measures. The primary management programme to be developed · Creation of artificial mineral licks in the NNT NBCA, with the and implemented for the key bird and mammal species, identified aim of drawing the elephants away from the currently exist- earlier as presently found on the Nakai Plateau, will be based on ing mineral licks to alternative mineral sources on the northern proactive patrolling and enforcement, not only for the plateau but side of the reservoir; and also for the NNT NBCA. · Identification and habitat improvement of "elephant islands". Management of Key Wildlife Species There is a strong likelihood that within time, the elephants will reuse their traditional routes, thereby causing escalation in As mentioned above, about 40% of the plateau will be inundated human-elephant conflicts. Thus, suitable "islands" should be and of the remaining area, about 50% of the forests are in rela- selected for habitat improvement before their formation. Cri- tively good condition. There may be sufficient habitat to maintain teria for selection should include only those islands that are viable populations of most of the Nakai Plateau fauna. However, along the elephants' routes and those that are well distanced some wide-ranging predators (e.g. tiger) are territorial and they from human selements. may require an area the size of the reservoir just to maintain a few breeding males. Other animals such as elephants move seasonally Of equal importance is reseling affected villages well away from between widely dispersed resources or ephemeral resources like the elephants' known range, as displaced elephants are likely to bamboo,andthereforerequirespecialmitigationandmanagement seek food in or near human habitations. Thus, distancing the reset- measures. The primary management programme to be developed tled villages (and where they are allowed to carry out agricultural and implemented for the 16 key bird and mammal species, identi- activities) will lessen the chances of human-elephant conflicts. fied earlier as presently found on the Nakai Plateau, will be based NTPC has requested the assistance and expertise of WCS for the on proactive patrolling and enforcement, not only for the plateau development and implementation of the elephant programme. but also for the NNT NBCA. This programme, to start in the dry season of 2004, is to design and test management plans that could serve to reduce potential Elephant Conservation Programme human­elephant conflict along the south shore of the reservoir. In TheAsian elephant is the key large mammal on the Nakai Plateau, order to do so, it is necessary to accurately determine the size and hence any programme designed to conserve this species will very distribution of the elephant populations across the entire Plateau, likely benefit other species using the same habitats. Thus, there assess the current habitat/resource use, identify seasonal move- needs to be a clear understanding of the area for the elephants, ment paerns and the quality of habitat that will be available to Terrestrial Biodiversity 131 EAMP Main Text elephantsaerinundation,includingthepresenceofothermineral camps and the labour force, the Headrace Channel and the upper licks. A Nakai District conflict response team needs to be trained and lower portions of tunnels, the Power Station and substations, and mobilised to gather systematic data on human­elephant con- and the Downstream Channel. The third part of this section deals flict across the entire Plateau, so as to provide district authorities with impacts linked to other specific construction and Project an understanding of conflict. The programme will work with vil- developments, such as the initial filling of the reservoir at the end lagers to test low-cost crop protection methods that have proven to of the construction period, the construction of roads, the Transmis- be successful in preventing human­elephant conflicts. sion Lines, the impacts associated with reselement, and potential Compensatory Forestry impacts to physical and cultural resources within the construction areas. A forest area of approximately 28,000 ha will be lost as a conse- quence of the Project, mainly in the area to be inundated by the Givven that some aspects of the design cannot be fully assessed reservoir (Singh, 2004). No endangered and endemic tree species until the construction techniques and requirements of the Head are expected to be lost. ConstructionContract(HCC)aredetermined,theEIAofthesecom- ponents can only be preliminary in nature and limited to identify- Project will restore a similar area of currently degraded forest, ing the major areas of consideration. Although several areas have under a compensatory forestry programme. If necessary, GOLwill been identified, the precise location of the quarries, spoil disposal provide the required land for compensatory forestry activities at sites, construction work camps and work areas are yet to be deter- no cost to the Project. mined. Before new quarries for, sand, laterite and sandstone are Different areas with a crown cover less than 20% and which could opened; an EIA is to be undertaken by the HC. For spoil disposal qualify for this programme have been earmarked. There are (i) sites, quarry sites, construction work camps and work areas, a plan the degraded forests within the NNT-NPA; (ii) the area reserved detailing the locations, designs and environmental safeguards will for the sustainable forestry component of the reselement action be prepared as part of the Head Construction Contractor's Envi- plan;(iii) degraded forests on the Nakai Plateau that will not be ronmental Management and Monitoring Plan (HCCEMMP), and affected by the inundation. If these areas are not sufficient, then will be prepared degraded forests outside of the area affected by the Project could Adiscussion of quarry sites, spoil disposal, and construction work be considered. camp areas is included below to present the framework within A rapid assessment of degraded forests in the Project area gives which the activities will be determined and to provide general approximately 32,000 ha of degraded forest within the NNT-NPA information on locations which have been identified as possible (Singh, 2004), out of which 28,000 ha could be set aside for natu- sites. Atleast 3 months before construction activities are sched- Impacts ral regeneration. It is believed at this stage that several hundreds uled. hectares could qualify under the sustainable forestry component of the RAP. A preliminary estimate gives approximately 15,000 ha The HCCEMMP will be the main document for the environmen- that will qualify for natural regeneration with very limited inter- tal management of construction activities. The plan will include ventions. Based on the available data, preliminary assessment a number of sub-plans for implementing protection and mitiga- indicates that the above regeneration scheme would cost about$4.2 tion measures addressing environmental impacts created by the million. construction activities. These sub-plans are listed in Table 3.65. Monitoring programmes will be developed to ensure that impacts Activities will start when the reservoir is created on the Nakai Pla- during construction are effectively mitigated and controlled. teau. During the five years aer this date, GOL and NTPC will confirm the availability of areas eligible for the compensatory for- The HCC contains a number of environmental requirements relat- estry programme, under the various options indicated above. Dif- ing to construction, termed the `Owners Requirements' (OR). ferent activities will be undertaken, including inter alia, detailed These requirements are presented in Annex L, and are designed surveys of the degraded areas, site selections, consultation with to ensure implementation of measures that will mitigate or mini- local people, development of management plans for these areas, mise impacts identified during the Project environmental assess- preparation of groundwork, including development of nursery of ment. The HCCEMMP must include all requirements specified in suitable native species. the Owners Requirements. The HCCEMMP is described further in Chapter 6. The second phase of the programme is expected to start from year six aer the inundation, and will be a combination of assisted General Impacts Generated by all Construction natural regeneration, enrichment planting, and other techniques Activities that will be identi.edidentified during the first phase of the pro- gramme. A monitoring programme will also be set up to evaluate All construction activities have the potential to have impacts on growth and conditions of the areas looked aer. $5 million will be water quality, air quality and noise. These impacts are described made available to undertake the compensatory forestry work ($4.2 in this section. million plus $0.8 million contingency) subject to confirmation of the detailed cost aer completion of the detailed field surveys on Water Quality the available degraded land in the NNT-NPA. Sources & Types of Impacts Impacts Associated with Construction Themajorsourcesofconstruction-relatedimpactsonwater quality will be from erosion of disturbed areas required for the construc- Generally, many significant impacts are observed during the con- tion activities (construction sites, concrete batch plants, material struction of hydropower projects. Most construction activities will storage areas, vehicle maintenance areas, spoil disposal areas), impact water and air, and will generate noise. Such impacts are from wastewater discharge at the construction camps, and from presented with associated mitigation measures in the first part of contaminated water (oil, grease, petrochemicals, cement, chemi- this section. The second part deals with specific impacts associated cals). with some specific construction activities, principally with con- The consequence of these impacts is the potential for introducing struction of the Nakai Dam, quarries, spoil disposal areas, work sediments and pollutants to water bodies during construction, 132 Impacts Associated with Construction EAMP Main Text thereby affecting aquatic habitats, fishes and water sources for res- Management Plan, and in accordance with the Pest Management idents and wildlife downstream of the construction areas. Plan Mitigation Air Quality The HC will be required to prepare several plans, including an Erosion and Sediment Control Plan, and a Water Quality Monitor- Source & Types of Impacts ing Plan, incorporating the requirements presented in Annex L. Vehicles and stationary equipment will impact air quality at the The following mechanisms will be used to mitigate and minimise construction sites through emissions from engines. Additionally, impacts on water quality: quarrying activities, concrete batch plants, construction work and 1 ­ Management of potential erosion and runoff from disturbed movement of vehicles along unpaved roads will generate dust and areas around the construction sites, including the following meas- impact air quality. The burning of waste will also affect air qual- ures: ity. · All runoff from construction areas, including concrete batch Mitigation plants, will be directed to sedimentation basins. Erosion con- Maintenance of vehicles and stationary equipment in good work- trolfacilitieswillbeinstalledthroughouttheconstructionareas ing order will reduce negative impacts on air quality. Spraying and will include silt traps, fences and sedimentation basins water on the unpaved roads will be used to control dust. The burn- where appropriate, depending upon the size of the catchment. ing of waste is discouraged and shall be done in designated areas The sedimentation basins will have adequate storage capacity away from selements. Burning of any materials which produce and are to be regularly inspected, with accumulated sediments toxic gases is not permied. The HC will be required to prepare an removed throughout the construction period; Emissions and Dust Control Plan. · Catch drains, diversion drains, table drains, windrows and associated drop-down drains will direct site runoff to estab- Noise lished watercourses. These will be inspected regularly for any damage caused by scouring, sediment deposition, channel Source & Types of Impacts obstruction and loss of vegetative cover, and all erosion control Sources of noise will include vehicles, excavation equipment, con- Impacts measures will be maintained; crete batch plants and crushers located at the construction sites. · Soil and spoil removed from the construction areas will be Other sources of noise will be explosives used for tunnelling and stockpiled separately and stabilised with grasses or other veg- to prepare the foundations and abutments for construction of the etation. This material will either be stored permanently at the dam. spoil disposal areas, or if possible returned to the original con- Noise in and around the construction area is likely to affect wild- structionareas. Attheendoftheconstructionperiod,construc- life and residents in nearby areas. Wildlife in the area is likely to tion areas will be re-graded to conform to the natural topogra- move away from the noise and eventually return to the area when phy of the areas.Aer placement, the areas will be seeded with construction is complete. grasses or shrubs of an appropriate variety to stabilise the soil and promote re-vegetation. It may be possible in some cases Mitigation to leave the area as graded and allow for natural invasion of Maintenance of the vehicles and construction machinery in good plants into the area. The regrading and replanting of the area working order and installation of noise mufflers on all engines will will restore wildlife habitat in the construction areas. · Erosion and Sediment Control Design Plans will be prepared andcomprisedetailsofimplementationofdrainageworks,sed- iment traps, diversions, culverts and other structures designed Table 3.65: Sub-plans of the HCCEMMP for implementing protection and to treat water to an acceptable quality before discharge into the mitigation measures natural watercourses. All structures are required to be in place prior to commencement of construction; Sub-plan 2 ­ Treatment facilities to remove oils and grease from drainage 1. Erosion and Sediment Control Plan water before discharge to adjacent watercourses will be installed. 2. Spoil Disposal Planning and Management Plan This is of particular importance for runoff from vehicle mainte- 3. Quarry Management Plan nance areas. Monitoring of oil and grease skimmers is required 4. Water Quality Monitoring Plan throughout the construction period. 5. Chemical Waste/ Spillage Management Plan 3 ­ Refuelling of heavy equipment and machinery will be under- 6. Emergency Plan for Hazardous Materials taken by a service vehicle, with appropriate safeguards and pro- 7. Emissions and Dust Control Plan tection measures to prevent spillage or contamination by chemical 8. Noise Control Plan wastes or maintenance oils and lubricants. All fuel and hazard- 9. Physical Cultural Resources ous material will be stored to minimise the potential for spills (the 10. Landscaping and Revegetation Plan requirements for the HC's Chemical Waste/ Spillage Management 11. Vegetations Clearing Plan Plan and Emergency Plan for Hazardous Materials are presented 12. Waste Management Plan in Annex L). 13. Reservoir Impoundment Management Plan 4 ­ Wastewater treatment plants will be installed to treat all waste- 14. Environmental Training for Construction Workers Plan water generated from work camps and other facilities associated 15. On-site Traffic and Access Management Plan with the construction of the Project (the requirements for the HC's 16. Explosive Ordnance Survey and Disposal Plan Waste Management Plan are presented in Annex L). 17. Construction Work Camps and Spontaneous Settlement Areas Plan 5 ­Any use of synthetic chemicals, especially relating to vegetation 18. Manual of Best Practices in Site management of Environmental Matters clearance, is required to follow the HC's Chemical Waste/Spillage 19. Project Staff Health Program Impacts Associated with Construction 133 EAMP Main Text reduce the noise nuisance. To reduce the impact of noise on wild- located upstream from the dam site and a concrete lined tunnel, six life,explosiveswillonlybeusedduringdaylighthourswhenwild- metres in diameter and around 200 metres long will enable diver- life is less active than during night time. The HC will be required to sion of water around the construction area. A second cofferdam prepare a Noise Control Plan that includes these measures will be constructed downstream from the dam site and will pre- Impacts Associated with Specific Construction vent backwater effects into the construction area.Adrawing of this arrangement is shown in Annex D. Activities At the end of the construction period, the downstream cofferdam Construction of the Nakai Dam will be entirely removed and the cofferdam upstream will be par- tially removed to El 520 m. The diversion tunnel will be perma- Areas to be Cleared nently plugged with 12 metres of concrete and the closure of the dam will then begin to fill the reservoir area and the minimum The areas to be cleared at the Nakai Dam site are shown in Figure riparian release regime will begin. At this point, the discharge in 3.60. Areas will be cleared and levelled to enable storage of equip- the Nam Theun will be affected but flow in the Xe Bang Fai will ment, materials and the placement of the concrete batch plant. An not, until discharge from operation of the Power Station begins. access road will be constructed to enable movement of vehicles to and from the construction site. The Nakai Dam construction will Impacts of Cofferdam & Diversion Tunnel Construction requirethediversionoftheNamTheunfromthedamsite,through Construction of the cofferdams and diversion tunnel will start a tunnel. Materials excavated from the foundation area will need prior to any construction activity of the dam itself. This is neces- to be taken off-site for disposal. sary to enable excavation of the foundation and abutment areas for Impacts of Clearing the dam. The main impact associated with cofferdam construction is sedimentation that it will create in the Nam Theun during the Construction may impact air quality (dust and engine emissions), period of construction, and then the diversion of water from the water quality (erosion and sedimentation, contamination), and Nam Theun through the tunnel, which will impact the movement wildlife and vegetation within the immediate vicinity of the con- of fish through the area. The timing of the close of the diversion struction area (destruction of habitats). Most of the activities and tunnel and dam will impact on the initial natural stocking density therefore the impacts associated with construction of the dam will of the new reservoir. occur during the dry season. For the most part, these disturbances will be temporary in nature and eventually the areas downstream Mitigation of Cofferdam Construction of the Dam will be returned to forested areas. Appropriate mitigation measures to limit sedimentation in the Impacts Nam Theun will be implemented. Mitigation of Clearing At the end of the construction period, the cofferdams will be Because construction of the dam will only occur during the dry removed, and an appropriate location for the spoil will be selected season, provision for maintaining the construction areas during (this will be included in the HCC Spoil Disposal Plan). Standard the wet season will be necessary. A primary concern for the con- recommendations for minimising soil erosion will be followed, struction areas is the potential for erosion of soils from the dis- including grading if necessary and revegetation (HCC Landscap- turbed areas. Mitigation of other construction impacts on water ing and Revegetation Plan, HCC Erosion and Sediment Control quality, air quality and noise are discussed above. Plan). Diversion of Water Scheduling of the closure of both the diversion tunnel and dam During the construction period, lile impact to the hydrologic duringthepeakofwetseasonwillallowearlywetseasonupstream regime of the Nam Theun is anticipated: one cofferdam will be migrating fish to increase the initial stocking density of the reser- voir. The timing of the closure needs careful consideration with other technical and economic aspects of the Project. Quarries Source of Impact Limestone aggregate, sand, laterite and sandstone will be required for various Project uses, such as road base for the new roads, and for concrete for the Nakai Dam, regulating dam, saddle dams, Power Station, intake structure, tunnels and portions of the Down- stream Channel. Some potential quarry sites have been identified as sources of limestone, sand, laterite and sandstone. These areas fall within three main zones: i) Nakai Dam site zone: three potential sand sources and two potential sandstone sources are located in this area. In addition, a limestone quarry has been identified at Phou Pha Phen, north of the Nakai Dam site area and near Ban Lak Sao and Road 8B; ii) Road 12 to Thakhek zone: in this zone, three sand sources and three laterite quarries have been identified; iii) down- stream zone: two laterite quarry sites have been identified near the Downstream Channel as well as a previously used, but currently not operational, limestone quarry located at Pha Thung, near the junction of Roads 12 and 8B. Material from the quarries will be crushed to appropriate size for Figure 3.60: Area to be cleared for construction of the Nakai Dam use in the concrete batch plant, and some material from the quarry 134 Impacts Associated with Construction EAMP Main Text will be used for riprap. Washing of the aggregate will also take Work Camps, Work Areas & Labour Force place at the quarry sites. Four zones have been identified for potential construction camp Type of Impacts development to accommodate a maximum construction worker Opening of the quarries will cause visual impacts because they population of approximately 4,000 workers. The selected areas are will remove a significant part of the hills. Other impacts will be the shown on Figure 2.18. Construction contraction will allow families noise generated during blasting and crushing, dust produced dur- of Lao workers to sele within the camps and will ensure that serv- ing blasting and crushing, transport of the aggregates, and trans- ices are provided within these camp, preventing the development port of materials to the nearby rivers. These noise and dust impacts of spontaneons, eitherly that will not be allowed by GOL authori- could affect wildlife in the area, ties in the proximity of the camps. Recent studies of the ecology of karstic formations in East Asia, Impacts cited in Vermuelen and Whien (1999) and Urwin and Berwick Potential impacts from the workforce and of the spontaneous (2002), have confirmed that isolated karstic formations have the development, at the work camps in all construction areas, will potential to harbour unique forms of life and create a different bio- be in terms of additional pressure on land and natural resources, logical diversity, due largely to the possibility of localised ende- including hunting near the camps and, directly and indirectly, on mism of species and sub-species. Vermuelen and Whien (1999) the NNT NBCA. The camps and the spontaneous development recommend the exploitation of limestone resources within large will generate solid and liquid wastes. Additionally, the spontane- tracts of karsts, rather than the destruction of an isolated karstic ous development near the construction camps could create public tower. The identified resource in the Phou Pha Phen area falls health risks, including an increase in the prevalence of sexually between these two options. It is an isolated outlier of a large con- transmied diseases, such as HIV/AIDS. solidated karstic formation some thousands of square kilometres Without treatment, wastewater from the work camps and the in extent spontaneous development could cause water quality problems Mitigation in adjacent water bodies, and could affect local populations, the labour force, new communities, and fish populations. Inappropri- Standard mitigation measures against erosion and sedimentation, ate solid waste disposal could lead to the contamination of soil and noise and air pollution will be taken, in particular for the use of rivers, and the spread of communicable diseases.. Impacts explosives. Mitigation At the end of the exploitation, quarries will be rehabilitated. This will include re-establishment of vegetation, restoration of natu- The environmental management of construction work camps will ral water courses, avoidance of flooding of the excavated areas, bespecifiedintheConstructionWorksCampdevelopedwithinthe achievement of stable slopes, and avoidance of features which HCCEMMP. Requirements for this plan are presented in Annex L. would otherwise constitute a risk to health and safety or a source Of particular importance, GOL will enforce strict regulations pre- of environmental pollution. venting hunting in the Project area, including in the NNT NBCA. The HC will be required to prepare a Quarry Management Plan Licenses to operate businesses, such as restaurants and bars, will as outlined in Annex L, and other plans to address the construc- be conditional upon appropriate disposal of wastewater, waste tion impacts discussed above (erosion and sedimentation, dust). and good sanitary conditions. These licences will be established, A specific Quarry Management Plan must be prepared for each reviewed and renewed regularly by GOL. Solid waste collection quarry site. and proper disposal outside of the reservoir area will be estab- lished to ensure that solid wastes do not affect water quality in the Spoil Disposal Areas adjacent water bodies (HCC Waste Management Plan). Impacts A Project Staff Health Programme will be established to educate and provide health services to the workforce relating to the pre- While some of the spoil material generated during excavation at all vention and control of disease vectors, communicable and sexually construction sites will be used in construction of roads, bunds, sed- transmied diseases. iment traps, landscaping and reselement village construction, the remaining spoil material will be placed in specific Spoil Disposal The same environmental provisions that apply to other construc- Areas. The total amount of spoil is estimated at approximately 15 tion areas will also apply to the construction work camps. million m3. In addition to the destruction of habitats covered by Construction of the Headrace Channel & Upper Tunnel spoil, other potential impacts could occur to water quality through erosion and sedimentation. Construction of the Headrace Channel will occur on the Nakai Pla- teau between the Intake Structure and the Nam Theun. A section The locations of the Spoil Disposal Areas will be determined once at the end of the Headrace Channel will be cleared of vegetation the process of optimising the construction engineering and align- and overburden to enable free flow of water from the reservoir, at ment options for the DownstreamChannelandotherProjectearth- its minimum operating level (MOL), to the intake structure. The works is completed. Figure 2.17 shows a number of sites that have upper tunnel will be constructed between the intake structure and been identified as potentially suitable and Table 3.66 presents the the Power Station. Construction will primarily involve excavation potential sources of spoil, estimated volumes, and probable dis- of materials from the Headrace Channel and the tunnel, and con- posal sites. crete lining. Mitigation Impacts The final sites for disposal will be determined through environ- Excavation of the Headrace Channel and the upper tunnel to the mental studies and local consultations, to be incorporated into the Power Station will involve movement of vehicles and the use of HCC Spoil Disposal and Management Plan, as per the require- excavating equipment, explosives and other types of machinery. A ments specified in Annex L. A plan must be prepared for each primary impact of this construction will be the placement of spoil site. removed from the Headrace Channel and the tunnel. Selection of Impacts Associated with Construction 135 EAMP Main Text Table 3.66: Potential sources of spoil and disposal sites Potential Location Estimated Volume of Spoil Generated (m3) Description of Anticipated Spoil Disposal Sites Nakai Dam 500,000 Spoil to be disposed upstream of dam, in dead storage of reservoir where possible, as well as stockpiled for road construction Headrace Channel 3,100,000 Spoil to be used for construction of saddle dams, sediment traps, and the remaining would be placed in spoil deposit zones within reservoir Headrace Tunnel, surge shaft & 155,000 Spoil to be deposited in spoil location across from access adit on Road 8B, with total capacity for access adit 230,000 m3 Pressure Shaft and Tunnel, 1,300,000 Required for switchyard platform (~500,000 m3), platforms for power station (60,000 m3), and other Power Station foundations, areas around left bank of regulating pond, which have an approximate total capacity of 2,400,000 m3 Tailrace Channel Regulating Pond 1,500,000 Spoil is to be used in construction of the Regulating Dam and deposited along edge of Regulating Dam and left bank of the regulating Pond Downstream channel 8,700,000 Approximately 5,200,000 m3 is estimated to be needed in construction of channel (banks as needed, access road parallel to channel as required). Preliminary sites have been identified along the downstream channel and further studies will determine their suitability for disposal of the 3,500,000 m3 Note: * indicates following year where the spoil materials can be placed will be a major considera- fish populations and pollution of water sources for residents living tion in the planning for the construction activities. downstream from the construction areas. The clearing of the area between the intake structure and the MOL As above, tunnel drainage water could also create impacts if dis- of the reservoir will be another source of impact. charged to adjacent water bodies without treatment. Construction of the intake structure will require the installation Mitigation of a concrete batch plant adjacent to the portal opening. The con- crete batch plant will also be used to mix the concrete necessary for Standard construction impacts will be mitigated as required by the lining the upper tunnel and for the lining of the surge chambers. various plans to be prepared by the HC (air quality, water quality, Placement of the concrete for the intake structure, tunnel lining noise, spoil disposal). Tunnel drainage water will be collected and Impacts and surge chamber will require movement of vehicles to the vari- treated during construction of the upper tunnel. ous locations. Installation of the concrete batch plant could also Construction of the Downstream Channel create some impacts associated with air quality, water quality and noise. Movement of vehicles bringing aggregate to the batch plant Impacts from the Pha Thung quarry could also create similar impacts. Construction of the Downstream Channel will involve a 27 km cor- Tunnel drainage water could also create impacts if discharged to ridor from the Regulating Dam to the Xe Bang Fai. In addition to adjacent water bodies without treatment. the construction itself, the main sources of impacts to the down- Mitigation stream reach include the change in hydrology of the Nam Phit, disturbance of land and the placement of spoil materials. Standard construction impacts will be mitigated as required by the various plans to be prepared by the HC (air quality, water quality, As the Downstream Channel will parallel the Nam Phit in some noise, spoil disposal). Tunnel drainage water will be collected and sections, its construction will affect the hydrology in the Nam Phit. treated during construction of the upper tunnel. However, changes in hydrology are not expected to be significant duringconstruction,asconstructionwillonlytakeplaceduringthe Construction of the Power Station, Lower Portion of Tunnel dry season when discharge in the Nam Phit is low. During the wet & Substations season, the discharge in the Nam Phit will likely be diverted to the Construction of the Power Station and the lower tunnel will have finished sections of the Downstream Channel and then returned to similar impacts to those identified for the Nakai Dam site and the the Nam Phit channel through a breach of the levees forming the Headrace Channel. The main potential sources of impacts include: banks of the Downstream Channel. The hydrologic change dur- i) disturbance of lands; ii) disposal of spoil material; and iii) opera- ing the construction period will likely affect fish populations that tion of construction equipment. migrate into the Nam Phit for spawning. Other potential impacts during the construction of the Downstream Channel relative to the Impacts changes in hydrology will be the interruption of irrigation systems A mixed deciduous and dry dipterocarp forest currently covers along the margin of the Downstream Channel. the area that will be disturbed for construction of the Power Sta- Mitigation tion. Much of the forest directly adjacent to the construction area is already degraded by road construction and agriculture. The During the construction period, lile mitigation is available for Power Station switchyard and substation construction will require changes in hydrology. the clearing of an additional two to three hectares of mixed decidu- Spoil Disposal Sites ous forest. While some of the spoil material will be used in construction of the Disposal of the spoil materials will require selection of an appro- roads, rim bunds, sediment traps, landscaping and reselement priate location. Indication of the locations of the spoil areas is pre- village construction, the remaining spoil material will be placed sented in Figure 2.17. in specific areas. The total amount of spoil is estimated at approxi- The major potential impact at the construction and spoil disposal mately 15 million m3. In addition to the destruction of the habitats areas includes erosion and the runoff of cement, oils and grease, covered by the spoil, other potential impacts could occur to water particularly during the wet season. This could result in damage to quality through erosion and sedimentation. The locations of the 136 Impacts Associated with Construction EAMP Main Text spoil areas will be determined once the process of optimising the m for four weeks to check the integrity of most of the Project construction engineering and alignment options for the Down- structures (hold point number 2); and stream Channel and other Project earthworks is completed. Figure · Stage 3: the Head Contractor shall control the impounding of 2.17 shows a number of sites that have been identified as poten- the reservoir from elevation 533 m to 538 m such that the maxi- tially suitable and Table 3.67presents the potential sources of spoil, mum gradient of rise is never greater than both 0.2 m/day and estimated volumes, and probable disposal sites. The final sites for one metre in ten days. The Head Contractor shall hold the level disposal will be determined through environmental studies and of the reservoir at full supply level for six weeks to check the consultations, to be incorporated into the HCC Spoil Disposal integrity of the Project structures (hold point number 3). Plan, as per the format of Schedule 12 of the Owner's Require- ments (Annex L). Impacts Other Impacts Associated with Construction When the Nakai Reservoir is filled, 450 km2 of land below El 538 m will be submerged. All existing vegetation and habitat Activities & Project Developments types in the inundation zone will be lost, as will be their current This section presents other impacts associated with the initial economic, social and subsistence values. filling of the reservoir, and impacts associated with construction During the filling process, some fuel wood and commercial timber activities and Project developments such as the roads, the Trans- could be recovered from the reservoir area. The original forest will mission Lines and the reselement sites. not regenerate within the reservoir area because of the inunda- tion. Initial Filling of the Reservoir With the rise of water level in the reservoir and the subsequent loss Filing Sequence of terrestrial habitats on the Plateau, including the few remaining stands of Pinus laeri, resident and visiting wildlife, including The length of time required to initially fill the Nakai Reservoir will birds,willneedtofindnewhabitatsandterritories.Alargenumber depend on when filling starts. Table 3.67 indicates the rate at which of islands will form on the western end of the Nakai Reservoir the reservoir will fill, based on a computer simulation. If reservoir and some animals might find refuge on these islands. However filling starts at the beginning of the wet season, the first hold point these habitats will not be large enough to accommodate all ani- could be achieved in two to four months. However, if the reservoir Impacts mals. Some animals, including some mammals and reptiles, might filling starts at the end of the wet season, the filling process would become stranded on these islands. It is also likely that animals on not be achieved until the start of the following wet season, almost the islands will become vulnerable to hunting, including cats, pri- a year from the initial start of the filling process. During the fill- mates, civets, wild cale, and ungulates. The seasonal migration ing it is assumed that the minimum riparian release of 2 m3/s will of large mammals, such as elephants, from the NNT NBCA to the be released from the Nakai Dam in compliance with the riparian Phou Hin Poun NBCA will be disturbed by the presence of the release requirement. reservoir, resulting in potential conflicts between animals and the Figure 3.60 shows the filling of the reservoir with a start time for local population. each month of the year. Mitigation During the filling process, the water level of the reservoir will be controlled by the operation of the Nakai Dam. Several hold points The lossof the stands of Pinus laeri on the Plateau will be compen- will be observed for testing the power tunnels and the Power Sta- sated by the protection of the remaining stands above the inunda- tion, as follows: tion zone at several sites north of the proposed reservoir and in the · Stage 1: the Head Contractor shall hold the level of the reser- southernmost sections of the Plateau. voir at elevation 527 m for three weeks to check the integrity of Aplan will be developed for the management of animal relocation most of the Project structures (hold point number 1); in order to reduce potential conflicts with the local population. · Stage 2: the Head Contractor shall control the impounding of An elephant programme that is currently being developed will the reservoir from elevation 527 m to 533 m such that the maxi- assess elephant population size, migratory paerns and resource mum gradient of rise is never greater than 0.5 m/day. The Head use to help provide recommendations on management strategies Contractor shall hold the level of the reservoir at elevation 533 to prevent elephant-human conflict. Table 3.67: Dates of water level meeting target levels for each calendar month Target EL 522 m El 525.5 m El 538 m Start Average Year Driest Year Average Year Driest Year Average Year Driest Year 01-Jan 29 Jan 15 Feb 20 Apr 21 May 23 Aug 12 Dec 01-Feb 17 Mar 8 Apr 20 May 6 Jun 25 Aug 1 Jan* 01-Mar 25 Apr 12 May 1 Jun 15 Jun 28 Aug 3 Mar* 01-Apr 14 May 1 Jun 5 Jun 18 Jun 31 Aug 4 Apr* 01-May 26 May 6 Jun 9 Jun 24 Jun 1 Sep 5 May* 01-Jun 6 Jun 13 Jun 17 Jun 1 Jul 4 Sep 5 May* 01-Jul 3 Jul 7 Jul 8 Jul 20 Jul 15 Sep 6 Jun* 01-Aug 2 Aug 8 Aug 5 Aug 21 Aug 3 Nov 7 Jul* 01-Sep 2 Sep 4 Sep 7 Sep 12 Sep 21 May* 8 Aug* 01-Oct 4 Oct 10 Oct 12 Oct 26 Oct 29 Jul* 9 Sep* 01-Nov 9 Nov 16 Nov 25 Nov 18 Dec 13 Aug* 10 Oct* 01-Dec 16 Dec 22 Dec 23 Dec 9 Mar* 18 Aug* 11 Nov* Impacts Associated with Construction 137 EAMP Main Text Figure 3.61: Reservoir filling Roadways · Ban Nam Niam to junction with dam access road near Ban The Project involves upgrading approximately 106 km of public Phonkeo: 12 km improvement to road to make it 7 m wide and conform to Project category B standards; roads and the construction of 56 km of new public roads. In addi- · Junction with dam access road near Ban Phonkeo to junc- tion, access roads and tracks, some of them of a temporary nature, tion with Phou Phako quarry access road near Ban Phonxai: will be constructed between public roads and Project facilities Upgrade of 8.5 km to existing road, to be 7 m wide and to con- to enable construction, operation and maintenance. Some of the form to Project category B standards; and roads and tracks, especially along the Downstream Channel, will · From the junction with Phou Phako quarry access road near Impacts be le in place for possible future use as intermient maintenance Ban Phonxai to Ban Lak Sao: Upgrade of 14 km of road, to be 7 access. m wide and to Project category B standards. This section presents: i) the design and construction requirements; As these potential upgrades are not yet finalised, they cannot be ii) an assessment of the environment that will be impacted by road specifically discussed in this section. However, the same mitiga- construction; iii) a discussion on the potential direct and indirect tion measures described below for the anticipated impacts of environmental impacts from the construction and use of the roads; the known road works will also apply to any Options Package and iv) mitigation strategies and measures. upgrades. The main focus of this section is on the two segments of new road Design & Construction Requirements alignments: i) the section of the road crossing the reservoir; and ii) the dam site access road. Upgrading of roads will not cause Roads will be designed to the criteria shown in Table 3.68 All other design and construction requirements will be in accordance significant environmental impact over and above that of the exist- with the Lao PDR Road Design Manual as published by the Min- ing roads, with the exception of impacts that will occur during the istry of Transport, or to AASHTO standards where the Lao PDR upgrading construction activities. Safeguards to ensure that road Road Design Manual does not provide the necessary information. upgrades will not generate additional disturbance to the environ- The design of the bridges and pavements will also comply with ment and will remedy any existing poor environmental perform- AASHTO standards. ance will be included in various sub-plans of the HCCEMMP which cover erosion control, landscaping and best practices in Environment Crossed by the Road Works drainage and earthworks. Routing of New Roadways Description of Roadworks The planning of design routes for the new roadways incorporated inputs from ground surveys to minimise social and environmental Description of Segments of Roads to be Upgraded & Constructed impacts and to provide for the best technical and financial solu- Details of segments of roads to be upgraded and constructed can tion. A formal alternatives analysis has not been conducted for be found in Figure 2.16 the siting of the new roadways as the proposed routings have Options Package proved to be highly suitable, with expected low environmental and social impacts.An alternative for Segment 6, running between Should the agreed quotation submied by the Contractor for the escarpment and the reservoir before joining the dam site and works described for all the roads above be less than US $30 million, Segment 7 (Figure 2.16) was rejected because of the disturbances it GOL may select items from the options package set out below in would have caused to the NNT ­ Phou Hin Poun NBCA corridor order that GOL Road Assets provided by NTPC reach the value of and because the route selected has less impacts on the corridor, US $30 million. The options all involve upgrades to existing roads which the road must unavoidably cross. and do not include the construction of any new roadways. The Reselement & Compensation options are: It is not anticipated that reselement will be required for the con- · Further upgrade to applicable roads to include double bitu- struction of the roads, as the areas crossed are sparsely populated. men surface treatment, rather than the gravel surface specified A survey using satellite interpretation and ground truthing is for Project category Aroads; being conducted to identify if and how much of the land that will 138 Impacts Associated with Construction EAMP Main Text Table 3.68: Design criteria for roads Design Item Category A Category B Category C Category D Traffic (vehicles/day) <300 <300 <300 <100 Terrain Flat Mountainous Mountainous NA Design Speed (km/hour) 80 40 40 40 Formation Width (m) 9 7 7 5 Number of lanes 2 2 2 1 Lane Width (m) 3 3 3 3 Carriageway (m) 6 6 6 3 Paved Shoulder (m) NA NA 0 NA Unpaved Shoulder (m) 2 x 1.50 2 x 0.50 2 x 0.50 2 x 1 Max. Gradient (%) 6 8 121 8 Min. Horizontal Curve (m) 250 60 60 60 Min. Vertical Curves: Crest (km) 5 1 1 1 Sag (km) 2 0.6 0.6 0.6 Max. Superelevation (%) 62 63 63 63 Crossfall: Paved (%) NA NA 2.5 NA Unpaved (%) 3 4 NA 4 Paved Shoulder (%) NA NA 4 NA Unpaved Shoulder (%) 5 5 5 5 Road Reserve (m) 40 Impacts Bridge Design Live Load HS - 25 ­ 44 HS - 25 ­ 44 HS - 25 - 44 HS ­ 25 - 44 Bridge width (m) 7 7 7 5 Bridges clearance (m) 4 4 4 4 Max. Pavement Axle Load (Tonne) 11 9.1 9.1 9.1 Flood Bridges (years) 100 100 100 100 Flood Culverts (years) 50 50 50 50 Pavement Gravel Gravel Concrete Gravel Notes: 1. Generally < 8% up to 12% maximum locally; 2. Super-elevation may be increased to 8% in selected locations only; 3. Super-elevation may be increased to 10% in selected locations only be crossed is currently used. Areas where compensation may be Potential Impacts requiredcanthenbepinpointed.Thedetailsofthisbaselinesurvey and the framework for compensation are presented in the SDP. Environmental impacts include both direct impacts at the road construction sites and in the immediate surroundings, and indirect Vegetation in the Area of Road Construction impacts in the adjoining area, such as induced economic, social The Nakai Dam site access road (Segment 7) will pass through or environmental effects, whether planned or spontaneous, which evergreen forest for the majority of its length. This habitat type is are the results of increased accessibility and lower transportation uncommon on the plateau itself, occurring only in small parcels. It costs. is widespread in the NNT NBCAand on the southern escarpment. Forest & Vegetation Clearing In the area of the road alignment, this forest varies from semi- An estimated 1,380 ha of forest vegetation will be cleared for road dense to dense forest (70% canopy cover) with trunk diameters of construction (refer to Figure 3.62). The largest area of clearing 20-60 cm. Floristically, the canopy consists of 80% non-deciduous (580 ha) is within mixed broadleaf and coniferous habitat. trees dominated by Dipterocarpus alatus and Hopea, Pterocarpus, Change in Hydrology Lagerstroemia and Anisoptera, which are all valuable timbers. The understorey is dominated by ferns and palms. The first 25 km of the new road alignment of Road 8B between Nakai and the point at which it turns northwards to cross the Segment 6 will traverse a mosaic of mixed deciduous and dry dip- inundation zone will traverse the edge of the future reservoir. The terocarp forests, which are generally restricted to the rim of the road has the potential to intercept runoff water entering from the inundation area. The forests along the road alignment are of open reservoir's southern catchment. In order to maintain access with structure with 30-50% canopy cover. The dominant species are the relocated villages of Ban Nakai Neua, Nakai (Oudomsouk) and primarily Dipterocarpus, with Lagerstroemia, Pometia, Schima, Ster- Nakai Tai at the edge of the reservoir, the road will traverse the eospermum and Cratoxylon, and to a lesser extent Pterocarpus and flanks of the slope of the plateau rim, separating approximately Pinus laeri. 5.5 km2 of catchment surface area from the reservoir. The drainage As it crosses the inundation zone, Segment 6 goes through a small towards the Plateau along this stretch is along numerous parallel area of unstocked forest, where all valuable timber species have gullies. been removed, leaving a 20-30% canopy cover and an understorey The new alignment, which crosses the inundation zone, will be dominated by Cyperus sp. and Cimbopogon sp. These open forest a combination of multi-span bridges and causeways linking the areas retain habitat value for many bird species, especially birds of multiple islands that are formed when the reservoir is filled. prey and insect feeders. Island Habitats Impacts Associated with Construction 139 EAMP Main Text The new alignment of Road 8B across the inundation zone will be eases may impact the health of communities and the construction in the form of a causeway. Fill will link the high points, which will workforce. be islands in the completed reservoir (at FSL). The area the road will cross is currently classified as unstocked and disturbed mixed Interference with Movements of Wildlife deciduous forests. When the area is inundated the high points will Road construction, human presence and traffic will interfere with become islands and the vegetation may act as wildlife refuges. the natural movements of wildlife. Erosion & Sedimentation Mitigation Parts of the alignment of Segment 6 are high gradient, and mitiga- Potential impacts are summarised in Table 3.79. They are accompa- tion measures will be incorporated to minimise impacts ­ particu- nied by recommended mitigation strategies designed to minimise larly on steep slopes and uns soils, where runoff and drainage will the significance of impacts. The table also presents an indication of be high. Excessive runoff and loss of soil can lead to vegetation parties that will be responsible for their execution and monitoring. damage, and thus deterioration of natural habitats and water qual- Mitigation of impacts commonly associated with other construc- ity. tion activities, such as erosion control, sedimentation, dust, pollu- Large-scale disturbance can also occur through slips and land- tion are not repeated here. They are detailed under the obligations slides in steep areas, particularly those involving high gradients of the HCC. such as the relocation of Road 8B between the escarpment and res- ervoir at FSL. Transmission Lines Dust This section provides: i) a description of the activities to be under- Dust raised from the road during construction, and subsequently taken to construct the transmission lines; ii) details of the existing raised by vehicles, can pose a health hazard and damage vegeta- environment along the transmission line routes; iii) a discussion tion along the side of the road. on the potential environmental impacts from the construction and Construction Workers operation of the lines; and iv) detailed mitigation measures to min- imise and/or eliminate adverse environmental impacts. The influx of new workers will add to the number of people in the area, potentially increasing hunting, fishing, and gathering of for- Description est products in areas adjacent to the roads. If not managed prop- Transmission Lines Characteristics erly, solid waste and waste water have the potential to contaminate The Project includes the construction of three Transmission Lines. soils, groundwater and nearby rivers and streams. The planned routes for the 500 kV and 115 kV Transmission Lines Impacts Disturbance to Crops are shown in Figure 3.63. In areas near the roads, there is potential for crops to be disturbed, The first line is the 138 km-long double circuit 500 kV Transmission damaged, or raided by animals as a result of construction of the Line, to deliver electricity from the Nam Theun substation adjacent roadways. In the case of upgraded roads, no significant increased to the power station to the transfer point on the Lao-Thai border impact is expected to crops as animals can already access these near Savannakhet. EGAT will take the electricity from the delivery areas on existing roads. With respect to Segment 8 (reselement point, through Mukdahan on the border, via a 500 kV Transmis- area roads) the roads will traverse through areas that are largely sion Line to a new substation at Roi Et in Thailand. unused for agriculture. In the case of the two new road segments, Segment 6 is a relocation of an existing road. A large part of this The second line is the approximately 77 km-long double circuit 115 segment of new road cuts through the reservoir and hence will not kV Transmission Line that will deliver electricity from the Nam disturb crops. Theun substation to the Thakhek substation. The Project will con- struct a double circuit 115 kV Transmission Line from the Power Car Interactions with Livestock & Wildlife Station substation to just north of Mahaxai, then a single circuit Traffic on the roads during construction and during operation 115 kV Transmission Line will be sent to Thakhek along existing might cause accidents with livestock and wildlife moving on the towers. The responsibility of the Project for the 115 kV Transmis- roads. sion Line towers will be from the Power Station substation to north Impacts on Natural Resources Linked with Economic Growth of the new Mahaxai. Lane Xang Minerals, operators of the Sepon The improved year-round access to the whole Project area from goldandcopperminingproject,haveconstructedthesectionofthe new and upgraded roads will enable people to sele in the area. 115 kV Transmission Line from Mahaxai to Thakhek independ- Use of the improved access will enable movement from one area to ently of the Project, and environmental impacts were analysed by another. This will translate into the development of roadside vil- Lane Xang Minerals separately. lages, and a potential increased pressure on the natural resources The third transmission line may incorporate a section of an exist- in the vicinity of the roads. The increased pressure will include ing 22 kV line, from the substation near the Power Station to Ban uncontrolled logging, hunting and fishing, wildlife and non-tim- Nakai (Oudomsouk). From this point, one line will extend to the ber forest product collection, livestock husbandry on the Nakai reselement area on the Nakai Plateau southeast of Oudomsouk. Plateau, shiing cultivation in forest areas and forest fires. These A second line will extend northeast to the bridge at Ban Thalang. impacts are expected during the economic development of the The Thai length of the Transmission Line from the middle of the Project area. Mekong crossing up to the main substation at Roi-Et, approxi- Public Health mately 161.2 km, will be constructed by EGAT. The influx of people into the area is associated with an augmented The 500 kV and 115 kV Transmission Lines are expected to include risk of transmission of diseases, including sexually transmied self-supporting laice steel towers and ACSR conductors, with diseases, including HIV/AIDS. More traffic on the roads during the 500 kV towers being approximately 65-70 m in height and the construction and operation could increase accidents within com- 115 kV towers approximately 30 m in height. The normal spacing munities living adjacent to the roads.Aquatic invertebrates known between consecutive towers is expected to be approximately 370 m to be vectors of disease could inhabit stagnant water created dur- for the 115 kV line and 450 m for the 500 kV line. The final design ing construction of roads. The increased prevalence of such dis- of the tower structures, conductor specifications and tower spacng 140 Impacts Associated with Construction EAMP Main Text Impacts Figure 3.62: Alignment of roads to be upgraded (dashed) and new roads (solid) showing estimated loss of vegetation (estimated avg. road width: 16m) Impacts Associated with Construction 141 EAMP Main Text Table 3.79: Impacts and mitigation strategies for road construction and upgrading Impact Mitigation Strategy Party responsible & Relevant HCC plans Construction Phase Impacts 1. Vegetation, habitat and other natural a. Offset by the enhanced conservation management of the NBCA WMPA resources loss and disturbance from new road construction b. Salvage logging arrangements HCC Vegetation Clearing Plan c. Design alignment to generally minimize impacts on vegetation HCC, design d. Construction management to ensure that disturbance is limited to HCC under the control of NTPC and GOL the road easement 2. Potential change to reservoir water move- Design road with adequate water movement structures to provide HCC, design ment and surface mixing in reservoir by unimpeded water movement in reservoir. road crossing (segment 6) 3. Erosion and sedimentation a. Restrict construction to dry season to the extent possible HCC, Erosion & Sediment Control Plan b. Protection of susceptible soil surfaces with seeding and/or mulch HCC, Erosion & Sediment Control Plan c. Protection of drainage channels with berms or fabric barriers HCC, Erosion & Sediment Control Plan d. Installation of sedimentation ponds HCC, Erosion & Sediment Control Plan 4. Spoil disposal Road design will seek to balance cut and fill volumes, with maxi- HCC, Spoil disposal planning and management mum use of cut for roadbase construction. plan 5. Creation of stagnant water bodies in pits a. Assessment of vector ecology in work areas HCC, Project staff health programme and drainage areas b. Adequate drainage structures HCC, Erosion and sediment control plan. c. Design drainage structures and bridges with minimum runoff coef- HCC, design ficients d. Mosquito protection measures HCC, Project staff health programme 6. Disturbance to aquatic habitats form ero- Adequate erosion control measures HCC, Erosion and sediment control plan sion and stream blockage Impacts 7. Hunting and fishing by construction workers Fisheries and wildlife management HCC, Environmental training for construction workers plan 8. Construction worker health and safety Training HCC, Project staff health programme 9. Dust, Noise Dust and noise control measures HCC, Emissions and dust control plan, Noise control plan Contamination of soil, groundwater and Solid waste and waste water management HCC, Waste Management Plan river Increase in road accidents Enforce traffic regulation and Improve health facilities NTPC, Resettlement and Regional health Programs. HCC, Project staff health program, HCC On-site traffic and access management plan Operating Phase Impacts 10. Interruption of drainage patterns Installation of adequate drainage works HCC, design 11. Threat to potential role of islands as Include impact of road in wildlife management studies and adaptive NTPC Wildlife programme and WMPA wildlife refuges management responses 12. Landslides, erosion Erosion control measures HCC, Erosion and sediment control plan 13. Creation of new pathway and habitats for Adequate drainage works HCC, design disease vectors 14. Erosion, vegetation loss from disposal of Avoid tipping cut spoil directly over edge of road Construction Contract and HCCEMMP cut spoil 15. Illegal logging in watershed Implement regulation and controls HCC, GOL, WMPA 16. Collection / depletion of non-timber forest Implement regulation and controls HCC, GOL, WMPA products in watershed Livestock/car interactions Signage, maximum speed on each section of roads HCC, On-site traffic and access management plan 17. Hunting, fishing and disturbance to Wildlife management HCCEMMP wildlife 18. Spontaneous development Implement regulation and controls HCCEMMP e known until negotiations are finalised with the relevant subcon- the international border. Transmission Line towers will be painted tractor under the HCC. to provide higher visibility in the Mekong crossing zone. Preliminary estimates indicate that the "footprint" of each tower The 22 kV Transmission Line will be constructed on pre-stressed may be 10 m x 10 m. Suitable types of foundations will be designed for each soil class and tower type. concrete poles. The Mekong River crossing will comprise one anchor and one sus- The design of the Transmission Lines shall be based on reliability pension crossing tower on each bank of the river, and two interme- based design, and shall comply with the requirements ofAmerican diate suspension towers, on pier foundations, one on each side of Society of Civil Engineers Manual No.74, Guidelines of Electrical 142 Impacts Associated with Construction EAMP Main Text stations will be located near the Power Station, known as the 500/115 kV Nam Theun substation and the 115/22 kV Nam Theun substation respectively. The 115/22 kV Thakhek substation is being constructed by EDL. In addition, land has been reserved at Savan- nakhet for a substation that may be constructed by GOL at a later date.Although the technical configurations of each substation will vary, the general requirements for the substations include: · Drainage systems and facilities (including oil/water separation and oil collection facilities); · Water supply and water treatment systems and facilities; · Wastewater treatment and disposal, and solid waste disposal systems and facilities; · Building services, including lighting, power, ventilation and air-conditioning; · Local monitoring, control, metering and protection systems and facilities for all substation auxiliaries and services, includ- ing interfaces to the Facility SCADA system for remote moni- toring and control; · Grounding systems and facilities, including interconnections with the power station grounding system; · Communications systems linking the substations with the power station and other points as necessary; · Buildings for housing all necessary control, monitoring, pro- tection and auxiliary equipment, including the substation con- trol room; · Maintenance workshops, storage space, and other facilities to Impacts provide for convenient and effective on-site maintenance and repairs, and for ease of trans-shipment of plant and equipment for off-site repairs; · Roads, pathways, drainage, hard stand, parking, maintenance and outdoor storage areas, security fences, gates, signage, security and work or task lighting and landscaping; and · Facilitiesforoperatingandmaintenancestaff,includingoffices, services and shaded parking areas. Routing of Transmission Lines Design Process: The selection of the design routes for the Project 500 kV and 115 kV Transmission Lines incorporated input from ground surveys undertaken during the development phase of the Project. The selection of the route was made to minimise social and environmental impacts and to provide for the best financial and technical solution. Aformal alternatives analysis has not been conducted for the route of the Transmission Lines as the original routing of the lines appears to be highly suitable, with low envi- ronmental and social impact. On or prior to the Construction Phase Commencement Date, NTPC's rights in respect of the Concession Period Category 1 and 2 Areas will be redefined to reflect design progress. Both boundaries of the Transmission System corridor that form part of the Conces- sion Period Category 1 and 2 Areas, may be moved outwards by up to one kilometre so long as such a move provides a clear net cost advantage to the Project and the relevant asset compensation Figure 3.63: Alignment of the 115 kV & 500 kV Transmission Lines provisions of the Concession Agreement are met. However, the total land area for the Concession Period Category 1 and 2 Areas Transmission Line Structure Loading, and ASCE Manual No.52, for the transmission corridor cannot be greater than the total land Guide for the Design of Steel Transmission Towers. area for the transmission corridor, as originally set out in the Con- cession Agreement. In addition to the activities required to construct the Transmission Lines, during the Operating Phase regular maintenance is needed In addition, within 12 months of the Construction Phase Com- that will require access tracks to the towers. These access tracks mencement Date, NTPC will reduce the Construction Phase Cate- will be maintained and kept clear throughout the operating phase gory 1 and 2Areas. The areas will be within the previously defined of the Project. boundaries and to the extent reasonably practical to reflect further design progress and actual areas needed for Construction Works. Substations All Construction Phase Category 1 and 2 Areas required by NTPC Substations, which include switchyards, will be constructed in will be justified in terms of final design requirements, construction several locations to support the transmission corridor. Two sub- working space and material source requirements. In requesting Impacts Associated with Construction 143 EAMP Main Text areas for construction activities, NTPC will minimise land distur- the road and transmission alignment are of open structure with bance and avoid the disruption of the natural environment and 30-50% canopy cover, with Dipterocarpus, Lagerstroemia, Pome- people living within the Project Lands. tia, Schima being the main species and Pterocarpus and Pinus also Where possible, the route of the Transmission Lines avoids areas present. of major vegetation. It should be noted that at no time will the The second branch of the 22 kV distribution line proceeds to the Transmission Lines pass through a protected area or any part of southwest reselement area. This line will also follow the roads an NBCA (Figure 3.63). The route has been carefully selected to to be constructed in that area. Alignment and, therefore, existing minimise impacts and any modifications to the Transmission Line terrain is not known since road alignments are not final. However, routing that may arise will ensure that this remains the case. the alignment will be designed to minimise impacts to vegetation Reselement: Ground surveys have been completed to avoid any and limit social disruption. need for reselement necessary for the construction of the trans- Geology mission lines. Should reselement issues arise, the Nam Theun The areas proposed for placement of the Transmission Lines are 2 Reselement Policy will be followed. If land is required that is not vulnerable to significant seismic shocks resulting from tectonic presently utilised, compensation will be paid as explained in the activity. Reselement Action Plan. Climate Thai Transmission Lines, impacts and compensation mechanisms Transmission Lines and substations will be designed to withstand EGAT has powers under the EGATAct of 1968 to purchase, occupy adverse climatic conditions prevailing along the routes, including anduseanylandorpropertytoconstructtransmissionlinesunder, wind, storms, pollution, humidity and temperature conditions, above,alongoracrossanylandbelongingtoanyperson.Onlyland and will be consistent with the applicable standards, and good under towers is permanently acquired. The rest of the land within design, engineering and construction practice. the electric cable line area remains the property of the land owner but with restricted use (no structures or trees over three metres in Vegetation & Habitat Types height). Figure 3.64 shows the different vegetation types crossed by the EGAT pays compensation at prevailing market rates for acquired Transmission Lines, based on the vegetation map prepared by the land, for the use of land for erecting transmission posts, and for National Office for Forest Inventory and Planning (NOFIP, 2002). the land that is declared an electric cable line area. The tower base Vegetation types are described in Annex H. is compensated at full replacement value; land in the ROW (which The Transmission Lines passing through dry evergreen forests and mixed deciduous forest will require clearing of vegetation along Impacts can continue to be cultivated) is compensated at 50-90 percent of the replacement value. Houses and other assets are compensated the route. Transmission Lines passing through dry dipterocarp at their replacement cost along with the affected residential land. woodland will require some clearing of vegetation. However, the Affected trees are compensated at a rate that takes into account the open nature of this forest will result in a lesser number of trees disruption in the income stream associated with the trees. felled than in other forest types. Clearing of vegetation from an Routing of the Thai Transmission Line estimated area of approximately 100 m2 will be required for the "footprint" or base of each tower. EGAT has modified, and lengthened, its first proposed align- ment to avoid a forest reserve traversed by the original alignment, Transmission Lines passing through areas of agricultural land will therefore removing the need to have an IEE conducted under the not require clearing other than the area occupied by the base of current Thai environmental regulation. The current Thai Environ- the tower. mental Assessment Guidelines require that a proposed transmis- Potential Environmental Impacts: sion line in Thailand needs an EIA if it falls in the area of Class 1B Watershed area, and an IEE if it traverses new forest reserve. In Environmental impacts for the Transmission Lines will occur pre- addition to the EIA/IEE requirement, EGAT would also need to dominantly during construction. The impacts are associated with obtain approval in the form of a permit from the Royal Forestry the clearing of the easements and access roads, and earthworks Department, before the clearing a public forest area. for tower construction. During the operating phase, impacts will be limited to electromagnetic radiation, visual impact and impacts Existing Environment associated with the access and the maintenance of the lines. Terrain Construction Phase Impacts The terrain through which the 500 kV Transmission Line will pass Disturbance to Vegetation for Transmission Lines: The removal of is moderately undulating for the first 40 km from the Power Sta- standing vegetation along the easements (Figure 3.65) and access tion. The remainder of the route to the Mekong River crosses rela- roads will be a significant impact. Within the easements, NTPC tively flat terrain. The altitude along the Transmission Lines varies will have the following rights during the Construction Phase: from El 180 m near the Power Station to El 105 m at the Mekong · To remove or trim vegetation that may intrude in the Construc- River crossing point. tion Period Category 1 Areas; The terrain through which the 115 kV Transmission Line section · To access the Construction Phase Category 1 Areas; and under the responsibility of the Project will pass is the same as · To support activities required to install, replace, or repair tow- the 500 kV Transmission Line until it ends north of the new Ban ers and/or transmission conductors of the Transmission Sys- Mahaxai. tem. The terrain through which the 22 kV distribution line from the In the Category 2 land, located primarily under the Transmission 115/22 kV substation and Ban Signo/Ban Thalang bridge passes is Lines between the towers, public access will be for purposes pri- the same as the roads on the Nakai Plateau. The 22 kV line will marily involving agriculture. follow the new alignment of Road 8B as it runs along the south- The methods to be used for clearing of vegetation have not yet ern edge of the inundation area from Oudomsouk to the Ban been finalised. However, clearing will be in accordance with the Thalang Bridge. The line will traverse forest areas that are gener- HCCEMMP, in particular the Vegetation Clearing Plan (Annex L). ally restricted to the rim of the inundation area. The forests along In particular, indications for the preparation of this plan stipulate 144 Impacts Associated with Construction EAMP Main Text tained in schedule 13 of the Concession Agreement on "Logging and Removal of Waste Forestry Products". The limit of allowable clearing for the Transmission Lines in the construction phase is stipulated in the CAand can be summarised as follows: Segment 1: 500 & 115 kV Line from the Nam Theun Substations to the Junction of Road 12, Near Ban Na Tung The 500 kV and 115 kV Transmission Lines will run in parallel for approximately 22 km. Separation of the Transmission Lines will be approximately 52 m. The easement, which is Category 2 Land, will extend 58 m at ground level from the centre of each 500 kV tower and 30 m from the centre of each 115 kV tower. The total width of the easement, including the 52 m separation between towers, is 140 m. The width of Category 2 land increases with height to enable cuing of dangerous vegetation. Category 1 land will be the footprint of each tower plus a two-metre perimeter. This is shown on Figure 3.65. Segment 2: 500 kV Line from the Junction of Road 12, Near Ban Na Tung to the Mekong Crossing In this segment, Category 2 Land will extend for 50 m on each side of the towers, making the total width of the easement 100 m. The width of Category 2 land increases with height to enable cuing of dangerous vegetation. Category 1 land will be the footprint of each tower plus a two-metre perimeter. Refer to Figure 3.65. Segment 3: 22 kV Line from the 115/22kV Nam Theun substation Impacts to the Reselement Area on the Nakai Plateau The 22 kV line will require very small clearance levels. Therefore, specific distances have not been prescribed in the CAas they have for the other segments of the Transmission Lines. It is anticipated that the alignment will follow the road routing and therefore will not require much additional clearing to that required for the road. Calculations of Potential Vegetation Losses The loss and perturbations of vegetation for the length of the various easements for the Transmission Lines in Segments 1 and 2, together with the section of the 115 kV Transmission Line from Ban Mahaxai to Thakhek (which is not under the responsibil- ity of the Project) during the Construction Phase is presented in Figure 3.64. Limited or no impacts are anticipated for Segment 3. More accu- rate data cannot be presented at this stage, as the final designs for the Transmission Lines are not complete. The vegetation structure is variable. Including the 115 kV Trans- mission Line section from Mahaxai to Thakhek, the major vegeta- tion losses will be in the dry dipterocarp forest (520 ha). The major- ity of the this forest is very open (20-40% projective canopy cover, Class 1) with a sparse or grassy understorey. Clearing of this forest is not expected to create a significant impact. The clearing of 160 ha of mixed deciduous forest will be in medium to dense forest. These forest areas exist in a densely seled part of the Mekong piedmont and have been subject to much disturbance and exploi- tation. The long use of these forests for timber, firewood, hunting Figure 3.64: Alignment of 115 kV & 500 kV Transmission Lines showing and gathering of non timber forest products has reduced their estimated loss of vegetation complexity and diversity. Consequently the habitat values are con- siderably less than those associated with similar vegetation in less accessible areas. that the application of herbicides shall be minimised to the great- est extent reasonable and practical. Use, application and storage of Additionally, the degree of selement and agricultural activity in herbicides will follow the recommendations of the Pest Manage- the Gnommalat Plain has resulted in extensive clearing that has le, in many cases, pockets of vegetation which are subject to ment Plan, presented later. intrusion and disturbance from all sides. If major trees form part of the vegetation to be cleared, then inter- In most cases, the lines will follow the perimeter of a forest. In one nationally accepted safety precautions will be followed, and clear- stretch however, the 500 kV transmission easement will bisect a ing will be carried out in accordance with the requirements con- long narrow band of dense forest running east-west. This area is Impacts Associated with Construction 145 EAMP Main Text located within Segment 2, approximately 15-20 km south of Ban Na Tung. It is in this area that the major impacts on vegetation will occur and where mitigation measures to minimise the effects will be focused. The clearing in this area will be for a 100 m ease- ment and may include the removal of the shrub layer in some sec- tions, during the construction phase only. The 100 m cleared strip is considered sufficiently narrow to still allow passage by ground dwelling animals and safe flight path for birds. There will be no development within the easement that could cause alienation of the natural land surface and cover. Conversion to agriculture or grazing should not be allowed in this portion of the Transmission Line route. Substations: The construction of substations will cause distur- bance to vegetation and some earthworks will be required during the construction phase. Details of each substation are not known at this stage and therefore it is not possible to fully assess the impacts on the environment. All vegetation clearing must be done in accordance with the Vegetation Clearing Plan, to be prepared by the HC. Where the 115 kV lines terminate at the Thakhek Substa- Figure 3.65: Category 1 & 2 potential area to be cleared for the 500 & tion, EDL will construct a substation independently of the Project, 115 kV line and environmental impacts will be analysed by EDL separately as part of the substations planning and design process. Similarly, if EDL elects to construct a substation at Savannakhet, the planning process will include an environmental assessment of the land that will be used for the substation. Access: Access trails to the Transmission System corridor may need to be constructed or improved. In order to access NTPC's Category 1 Project Land for the Transmission System corridors, Impacts NTPC may undertake construction to improve the quality of selected access trails. All existing access trails, roads and paths in or across the Construction Phase Category 2 Area for the Trans- mission System will be maintained and/or temporary routes estab- Figure 3.66: Category 2 potential area to be cleared for the 500 kV line lished as close as is practical to the existing positions. In particular, several access routes have been identified to assist in the construc- tion and maintenance of the 500 kV lines. A maximum of 23 ha of Between towers there is provision for clearing vegetation over vegetation could be cleared to improve access trails to Segments 1 3 m in height for the 500 kV line during the Concession Period. and 2 of the Transmission Line, including the 115 kV section from The EGAT standard was adopted to allow the use of the land Mahaxai to Thakhek, with 16.8 ha in dry dipterocarp forests, 5.7 for agriculture purposes, but not for forest plantations. The lim- ha in mixed deciduous forests and 0.75 ha in dry evergreen for- its of allowable clearing for the Operating Phase of the Project, est. This assumes: i) one access road for every 6 towers, although as stipulated in the Concession Agreement, are presented on NTPC does not currently have rights to land for a track for every Figures 3.65-3.66. 6 towers; ii) an average 1.5 km access track; and iii) a 4 m gravel track. EDLis responsible for the maintenance of the 115 kV Transmission Line section from Mahaxai to Thakhek. At this stage, no specific Earthworks: Earthworks associated with tower construction will information is available on vegetation to be cleared for mainte- be limited to four sunken concrete footings, one for each "foot" of each tower. While tower construction will require a considerable nance purposes. amount of ground level disturbance, it will not extend beyond the The 22 kV distribution line will require very small clearance levels easements for the lines. Following construction, much of this land and specific distances have not been prescribed in the Concession can be reclaimed for agricultural purposes. Agreement. It is anticipated that during the Operating Phase, dis- Mekong River Crossing: To enable placement of an adequate turbance to vegetation will be minimal. foundation for the two towers that will be constructed in the Substations: Impacts of substations in the Operating Phase will be Mekong River channel, some excavation in the river channel will minimal, and limited to the trimming of some vegetation and the be required. This excavation could create some increased sediment maintenance of access tracks. in the river. In addition, construction might have local impacts on navigation and fisheries in the Mekong River. Electric & Magnetic Fields: Calculations of the expected electric and magnetic fields for the 500 kV and 115 kV Transmission Lines Operating Phase Impacts are presented below to assess the impacts of electric and magnetic Disturbance to Vegetation: Within the easements of the Transmis- fields caused by the Transmission Lines on human health. sion Lines, during the Operating Phase NTPC will have the rights to: i) remove or trim vegetation which may intrude into the Con- Electric field for the double-circuit 500 kV Transmission Line cession Period Category 1 Areas; ii) access the Concession Phase (Operating Voltage = 525 kV): the results of calculations are pre- Category 1 Areas; and iii) support activities that require installa- sented in Figure 3.67 as the electric field profile across the ease- tion, replacement, or repair to towers and/or transmission conduc- ment at 1 m above the ground. tors. 146 Impacts Associated with Construction EAMP Main Text Electric field for the double-circuit 115 kV transmission line (Oper- shows the existing village locations, as well as the currently pre- ating Voltage = 120 kV): Figure 3.68 presents the electric field pro- ferred reselement location for each of the villages, based on vil- file generated across the easement at 1 m above the ground. lage initial preferences elicited during consultation sessions. Magnetic fields for the double-circuit 500 kV Transmission Line: The sites identified cover a gross area of 3,400 ha, of which 800 ha the results of the magnetic field calculation for different horizontal will be in the draw down zone. As the reservoir recedes in the dry distances from the centre of the 500 kV double circuit Transmission Line, and at 1 m above the ground, are presented in Figure 3.69. season, this zone is expected to be used for vegetable garden plots The following line conditions were considered: i) load current of and grazing cale and buffalo (RAP, 2002). Residential areas will 2,000 A; ii) phases of the two circuits inverted (A, B, C and C, B, A form the core of the village, surrounded by gardens and fields with from top to boom for low reactance arrangement of phases); and forests at a greater distance from the core. The actual plan of the iii) minimum conductor-to-ground clearances of 11 m and 14.5 m new villages will depend on the specific location of each new site Magnetic fields for the double-circuit 115 kV Transmission Line: and discussions with villagers as to where the various households, Figure 3.70 presents the magnetic field profile across the ease- buildings and fields should be located. NTPC will ensure that ment of the 115 kV double circuit Transmission Line for different housing is located above the FSL of the reservoir. House designs horizontal distances from the centre of the Transmission Line. The have been developed through consultations with the villagers who magnetic field profile was calculated at 1 m above the ground for are to be reseled. Houses will be elevated on posts and will be the following conditions: i) load current of 645A(based on the cur- allocated an area of 14 m2 per person, with a minimum housing rent rating of Hawk conductor at 75° C); ii) inversion of the phases area not less than their current existing area or 42 m2 (whichever is of the two circuits (A, B, C and C, B, A from top to boom for low greater). Each household will be entitled to 0.5 ha of land for their reactance arrangement of phases); and iii) minimum conductor-to- house and farming activities. Additionally, up to 0.15 ha of rice ground clearances of 7 m, 9 m and 10.5 m. land will be allocated to each household in an off-lot location, to be Electric & Magnetic Fields for 22 kV Transmission Line: The use of developed and allocated on a community basis. Community infra- 22 kV lines is standard international practice for power distribu- structure to be supplied includes: irrigation water to the house lot, tion in residential areas. It is therefore anticipated that the electric irrigation to rice fields, year-round household water supply and and magnetic fields for the 22 kV transmission line will be within Impacts acceptable international guidelines. Health Effects of Electric & Magnetic Fields: Limits of exposure to electric and magnetic fields endorsed by the International Com- mission on Non Ionize Radiation Protection are presented in Table 3.70. Levels for the electric and magnetic fields at the edge of the ease- ments are acceptable. However, the electric field exposure char- acteristics for the 500 kV Transmission Line exceed the "up to 24 hours per day" guideline. This field is expected to exceed the rec- ommended level at distances of approximately 3-17 m from the centre of the 500 kV Transmission Line (Figure 3.67). Mitigation measures will ensure that human habitation (and therefore 24- hour exposure) within the easement of the Transmission Line will not occur. Therefore, it is expected that no public health impact from electric and magnetic field will be associated with the Trans- mission Lines. Figure 3.67: Electric fields double-circuit 500 kV Transmission Line Assumptions made for modelling: Wire type ­ steel/aluminium, = 11.36 mm, mid- Mitigation & Monitoring span ground clearance = 42.2 m, horizontal distance from the centre of the line = 8.62 m. Assumptions are based on standard practice as final configuration has not Compensation mechanisms for lands affected in Lao PDR by the been finalised. Transmission Lines are presented in the SDP with the other Project lands. Potential impacts associated with the Transmission Lines are sum- marised in Table 3.69, with an indication of mitigation strategies and parties responsible for execution and monitoring. Resettlement Sites The purpose of this section is to evaluate the impacts of the reset- tled people and their livelihood activities on the existing land and natural resources. Impacts of the 22 kV electricity distribution line and roadways crossing the reselement area are addressed under the Transmission Line and Roadways headings. Description The proposed reselement area of approximately 21,000 ha is situ- ated on the southwest side of the proposed reservoir. Twenty-five potential village relocation sites adjacent to the reservoir's edge Figure 3.68: Electric fields double-circuit 115 kV Transmission Line at FSL have been identified, each ranging in area from 30 to 306 Assumptions made for modelling: Wire type ­ steel/aluminium, Ř = 10.5 mm, mid- ha, suitable to accommodate the 1,251 households (5,599 persons) span ground clearance = 18.9 m, horizontal distance from the centre of the line = 0.0 m. Assumptions are based on standard practice as final configuration is not (GOL Census Survey, 2003) eligible for reselement. Figure 3.71 finalised. Impacts Associated with Construction 147 EAMP Main Text Table 3.70: Limits of Exposure to Electric and Magnetic Fields electricity, community meeting hall, rice mill, access to house, and (source: Australian National Health and Medical Research Council, 1989, Interna- access to schools and clinics. tional Commission on Non Ionizing Radiation Protection, 1993) Existing Environment Exposure Electric Field Magnetic Flux Characteristics Strength (V/m) Density (mG) Vegetation Types Occupational The predominant vegetation type in the Reselement Area is Whole working day 10,000 5,000 broadleaf and coniferous forest (52% of the total area). Other veg- Short term 30,0001 50,0002 etation types represented are dry evergreen (18%), temporarily General Public unstocked (10%), and mixed deciduous (16%) forests, with 1.7% of Up to 24 hours/day3 5,000 1,000 the entire area classified as urban (RAP, 2002). Four hours/day4 10,000 10,000 Table 3.71 shows the vegetation/land use type within the Resele- Notes: ment Area. 1. The maximum duration of exposure to fields between 10 and 30 kV/m may be The broadleaf and coniferous forests are found in more open calculated from the formula t = 80/E, where t is the duration in hours per work day and E is the electric field strength in kV/m areas and are oen associated with poor, dry soils. Much of the 2. The maximum exposure duration is two hours per work day unstocked forests have been disturbed in the past by shiing cul- 3. This restriction applies to open spaces in which members of the general public might tivation and logging. Some have an overstorey of Pinus laeri, but reasonable be expected to spend a substantial part of the day such as recreational areas, meeting grounds and the like the stocking is very low. Many trees are of poor quality, having 4: These values can be exceeded for a few minutes per day provided precautions are been tapped for resin and burnt severely over time. The majority taken to prevent indirect coupling effects (61%) of the land has a slope of less than 15°. Impacts Figure 3.69: Magnetic field profile across the easement for 500 kV Trans- Figure 3.70: Magnetic field profile across the easement for 115 kV Trans- mission Line, based on a load current of 2000 A mission Line, based on a load current of 645 A. Table 3.71 Impacts and mitigation strategies for the Transmission Lines Potential Impact Mitigation Strategy Responsible Party & Relevant HCC Plans 1. Vegetation, habitat and other natural a. Avoid trees and clusters of vegetation as HCC, design resources loss and disturbance from much as possible transmission lines construction b. Limit use of chemicals for vegetation clear- HCC, Vegetation clearing plan ing along easements c. Reclaim land under lines after construction HCC, Landscaping & revegetation plan 2. Soil toxicity from application of chemicals a. Limit use of chemicals for vegetation clear- HCC, vegetation clearing plan used in clearing vegetation ing along easements b. Avoid application of chemicals in agricul- HCC, vegetation clearing plan tural areas 3. Possible health risks associated with elec- a. Prohibit dwellings, overnight houses, and GOL tric and magnetic fields generated from businesses in the easements along the transmission lines transmission lines 4. Risks of collision with vessels and air- a. Paint towers to provide higher visibility in HCC, design crafts the Mekong crossing zone. 5. Disturbance to vegetation from routine a. Avoid maintenance in wet season whenever NTPC operational maintenance possible b. Restrict operations to within the lines of NTPC easements 148 Impacts Associated with Construction EAMP Main Text Soils on the proposed alignment, which EGAT would make every effort The soils of the Reselement Area, as on the Nakai Plateau, are to avoid. Construction of 300 towers would require permanent generally heavily leached sandy loams, low in nutrients, shallow, acquisition of 12 hectares of the ROW land of an estimated 2000 and susceptible to erosion. These soils are poorly suited for inten- plots in private ownership. sive rice production or other forms of intensive arable agriculture. The land is best used for pine, combined with some NTFPs and Potential Environmental Impacts low-intensity understorey grazing. Loss & Disturbance of Natural Habitats Current Livelihood Activities The 0.5 ha multiple use home-garden lot will require intensive use Traditional livelihood activities are subsistence level rice cultiva- of approximately 500 ha of the reselement area. An additional tion, raising livestock, hunting and fishing for meat, and gathering area of approximately 200 to 250 ha will be used for the devel- of non-timber forest products. Livestock is traditionally regarded opment of community infrastructure (schools, roads between as a source of cash rather than raised as a source of food. In 2000, houses, and irrigation facilities). In total, 750 ha is expected to be the dominant livestock type owned on the Nakai Plateau, buf- used intensively and to cause loss of the natural habitats and their falo, numbered 4,100 within the inundation area. This represents resources in the reselement areas. Villages will be mostly located an average of 3.3 head per household, although the distributed is within 500m of the reservoir maximum operating level; this area skewered with some households owning 30-40 buffalo and others is characterised by unstocked and degraded forest. Much of the owning none. A shortage of feed is reported by some from March area has already been disturbed by shiing cultivation and log- through May. There is currently no supplemental feeding or man- ging activities, and therefore will require minimal clearance. Dur- agement of forage (RAP, 2002). ing drawdown of the reservoir, some sites that would normally be Thai Transmission Line. islands will be available for understorey grazing, particularly near The proposed Thai 500kV transmission line would require a 60- the villages Ban Nakai Tai, Nakai Neua and Nong Boua Kham. metre wide right of way (ROW), consisting of 972 hectares of land. Erosion & Degradation of Soil Eighty percent of the proposed ROW is mainly under paddy with Livestock paths have the potential to trigger erosion, particularly some other crops also under cultivation. The remaining twenty around natural water points. Dragging and skidding of logs can percent is under fruit orchards and plantations. There is one house cause compaction of soil, and tree thinning and logging can cause Impacts Figure 3.71: Vegetation types within and adjacent to proposed resettlement area, with existing village locations and proposed village resettlement sites Impacts Associated with Construction 149 EAMP Main Text Table 3.72: Vegetation within the proposed resettlement area the surrounding area. This is discussed in the Social Development Plan. Area (ha) Description 14.8 Bamboo Physical Cultural Resources 101.7 Urban & Built-up Area 108.5 Other Agricultural Land A number of physical cultural resources (PCR) within the Project 142.2 Water Bodies Area will be impacted by Project activities. These resources are 263.8 Swamp either part of the cultural traditions of the villages located within 351.5 Coniferous Forest the reservoir area, and will be affected by inundation, or are resources within or adjacent to Project Lands that may be affected 500.7 Rice Paddy by construction activities. Surveys were conducted to determine 609.8 Ray/Fallow Land the presence of PCR within the Project Area. A PCR Plan was 9,318.5 Unstocked/Degraded Forest developed with the aim to manage impacts and to ensure that PCR 27,851.8 Mixed Deciduous will be handled properly and in accordance with the relevant GOL 38,774.5 Dry Evergreen regulation (Decree of the President of Lao PDR on the Preserva- 117,227.9 Mixed Broad-leaf & Coniferous tion of Cultural, Historical, and Natural Heritage, 1997) and World Bank Operational Policy Note 11.03 and Operational Policy 4.11. A summary of the PCR Plan is outlined below with a more detailed erosion on steep slopes. Soil fertility can be lost from the exces- discussion presented in Annex P. sive removal of vegetation, erosion, and soil compaction. Increased runoff as a result of vegetation clearing and soil compaction can Surveys and Studies decrease the infiltration capacity of the soil. Burning of the vegeta- In the 1990's, two separate studies were conducted, in associa- tion can in the long term deteriorate soil fertility and structure. tion with the MIC, to determine the presence of cultural resources Wildlife & Aquatic Resources within the Project Area. The first survey was conducted during In the Reselement Area, wildlife and aquatic resources could the feasibility phase of the Project in 1990 (SMEC 1991) and con- potentially be subject to overexploitation. Interaction between the centrated on 26 locations within and around communities on the reselers and wildlife is likely to be important for the protection of Nakai Plateau. A second survey was conducted in 1994-1995 and crops and livestock, in particular with elephants. included the Downstream Channel as well as the Nakai Plateau (TEAM 1995).Ateam of archaeologists and social scientists further Impacts Water Quality updated the field identification and consulted with the local com- Adversewaterqualitycouldpotentiallyresultfromactivitiesinthe munities about acceptable management measures. reselement sites. The potential impacts include increased levels An additional survey was conducted in 2004 to take into account of nutrients (nitrogen and phosphorus) in the reservoir from over- more clearly defined land requirements of the Project and to adopt use of fertilisers for intensive forage plots and vegetable gardens, the definition of PCR to encompass not only sites of prehistoric, pollution of water by livestock grazing in the drawdown area, and palaeontological and historic value, but also religious, sacred and inadequate wastewater disposal. Water quality could potentially unique natural values. Earth Systems Australia (ESA), in associa- be impacted by the misuse of pesticides and herbicides in relation tion with the Department of Museums and Archaeology, and the to agricultural activities, vector control, insect and animal pest Institute of Cultural Research, within MIC, undertook a PCR Sur- control and vegetation clearance in the reselement area. vey to (i) document all identified sites of PCR significance that will Groundwater be potentially impacted by the Project; (ii) identify the impact; and (iii) present management and mitigation measures. Groundwater will be developed for domestic use and irrigation, depending on availability. Once inundated, irrigation water will The Survey assessed PCR both within and adjacent to Project be sourced from the reservoir, so irrigation should not impact on Lands and encompassed the Nakai Plateau, the Downstream groundwater quality and quantity. The long term extraction of Channel area and the impact corridors associated with the Xe Bang groundwater should be sustainable, especially with the inherent Fai, 500 KV Transmission Line and various road construction and recharge exhibited during the dry season. upgrades. Spontaneous Reselement The PCR Survey adopted the World Bank (OP 4.11) definition of PCR which covers movable and immovable objects, sites, struc- The provision of new infrastructure, economic opportunities and tures, groups of structures, natural features and landscapes that services will draw spontaneous migrants to the area. Planning have archaeological, palaeontological, historical, architectural, should anticipate some population increase in the area beyond the religious, aesthetic, or other cultural significance. 5,684 persons affected by the inundation of the reservoir. Controls In summary, the methodology comprised of community consul- will be imposed on in-migration given the proximity of the NNT tations, satellite imagery interpretation, transects and walk-over NBCA. surveys.All identified PCRsites and objects were documented and Mitigation & Monitoring subjected to a comparative study and contextual analysis to meas- ure their significance. Potential impacts identified are listed in Table 3.73 They are accompanied by recommended mitigation strategies and indica- Baseline tion of parties that will be involved for their implementation. It The results of the ESA (2004) PCR Survey are summarised below. must be noted that the land available for reselement has a limited Locations of PCR are indicated in Figure 3.72 and examples of the capacity in terms of the number of people that can be supported types of the PCR are shown in Plates 25 to 30 a more detailed pres- through food self-sufficiency, it cannot support a subsistence liveli- entation of all sites of PCR can be found in Annex P including a hood economy for the 5,800 people. The reselement will have to physical and cultural description of each site and an assignment be accompanied by a shi from a subsistence economy to a market of the level of significance. The PCR context of the Project Area is economy, to avoid resource exploitation and shiing cultivation in also discussed. 150 Physical Cultural Resources EAMP Main Text Table 3.73: Impacts and mitigation environmental protection at the resettlement sites Potential Impact Mitigation Strategy Parties Responsible 1. Vegetation, habitat and other natural resources loss a. Vegetation Clearance Plan to be submitted to the GOL NTPC and disturbance b. Design siting of works to avoid large trees and dense vegetation as much as possible c. Sustainable management of 10000 ha of the Resettlement Area by the Nakai Plateau Forest Association. 2. Erosion and sedimentation a. Restrict construction to dry season NTPC b. Protection of susceptible soil surfaces with seeding and/or mulch c. Protection of drainage channels d. Installation of sedimentation ponds e. Avoid areas vulnerable to erosion for development of new villages 3. Creation of stagnant water bodies in pits and drain- a. Assessment of vector ecology in work areas NTPC age areas b. Adequate drainage structures c. Mosquito protection measures 4. Increased interactions between wildlife and resettlers a. Grazing areas will avoid the proximity of intact forests. b. Development of a management plan for the population of elephants in the reservoir. 5. Disturbance to aquatic habitats from erosion and a. Adequate erosion control measures NTPC stream blockage 6. Uncontrolled NTFP collection, hunting and fishing a. Fisheries and wildlife management, in particular reservoir fisheries plan. GOL b. Register guns in RA and in the NBCA c. Register boats in the reservoir area 7. Generation of solid and domestic waste a. Proper waste treatment facilities and disposal NTPC/GOL Impacts 8. Burning vegetation for brush control and shifting a. Implement a controlled burning program NTPC/GOL cultivation b. Minimize the area of burning c. Prohibit shifting cultivation in resettlement area 9. Exceeding the carrying capacity of grazing lands by a. Monitor and control forage quality, occurrence of unpalatable weedy species, NTPC/GOL high densities of livestock and livestock density b. Avoid the use of soils susceptible to erosion for gazing c. Rotational grazing d. Control access of livestock with strategic placement of salt and water sources, and fencing 10. Dragging and skidding logs, and increased traffic in a. Use regular tracks and loading areas NTPC/GOL agroforestry activities 11. Reduction in soil quality and nutrients from tree a. Plant cover crops between rotations NTPC/GOL harvest and thinning for agroforestry b. Apply fertilizers where necessary 12. Increased nutrient runoff to rivers and the reservoir a. Rotational grazing of livestock in drawdown zones NTPC/GOL from livestock grazing in drawdown zones, inad- b. Prohibit the use of fertilizers in the drawdown zones equate wastewater disposal, and the use of fertiliz- ers in intensive forage plots, vegetable gardens, and c. Provide adequate wastewater treatment facilities forest plantations d. Locate homes above El 540 m e. Implementation of erosion control measures 13. Uncontrolled logging from increased access to for- a. Implement regulation and controls on logging NTPC/GOL ested areas from development of new infrastructure 14. Spontaneous development from development of a. Implement regulation and controls on spontaneous development GOL new infrastructure 15. Threats to physical cultural resources a. Survey the area for PCRs and recommend mitigation measures to minimize NTPC/GOL impact b. Employ good site selection techniques Prehistoric Sites years old and may have been the centre of Buddhist influence on There is evidence of Neolithic and Palaeolithic human occupation the Nakai Plateau. The temple location is outside of the inundation in a number of limestone rock shelters and caves within the Pha zone. Phen area (Plate 21). One cave of potential prehistoric significance Sixteen historic, and potentially historic sites, were identified in was also identified in the Downstream Channel area. It is not antic- the Downstream Channel area. From the end of the 17th century ipated that the Project will significantly affect the archaeological the Gnommalath and Mahaxai region hosted a prosperous society value of this site. which built numerous Buddhist temples. The most significant sites Historic Sites identified are Kouan Ku, Wat Tha Pha and the abandoned tem- ple of Wat That. All of the historic sites are located outside Project Four historic, and potentially historic sites, were identified on the Lands however there is potential for increased access to result in Nakai Plateau. The most significant of these sites is the abandoned the the of movable objects and/or physical damage to historic temple in Ban Nakai Tai which is believed to be approximately 200 structures. Physical Cultural Resources 151 EAMP Main Text In total nine sema stones were identified in a linear arrangement spirit sites is Pha Pet, located 400 m to the north of the Pha Phen near Ban Na Nouang and adjacent to the Transmission Line Cor- Quarry. ridor. Traditionally sema stones were located at temple sites and as border markers for states of power, the stones offering protec- Religious Sites tion against invaders. The sema stones are believed to predate the A total of 44 religious sites were identified, typically comprising 18th century. of Buddhist temples and stupas but also a number of Christian More than 50 abandoned lime kilns are located on the Xe Bang churches. Temples were commonly identified as repositories for Fai embankments, both upstream and downstream of Mahaxai. It movable objects of PCRsignificance including Buddha images and is believed that the kilns were established in the mid 1800s and manuscripts. production ceased in the 1950s. Lime was traded with selements alongtheXeBangFaiandasfarastheconfluencewiththeMekong Twenty-fourofthesereligioussiteswereidentifiedasbeinglocated River in Nakon Phanom. Isolated kilns have previously been iden- within or in close proximity to the Project Lands and thus may tified in Lao PDR however the scale of lime production and how be subject to land loss, disturbance to religious amenity, physical it may have influenced the historical development of the Mahaxai damage to religious structures and/or the of movable objects. area is unique. SitespotentiallyincurringthemostsignificantimpactsincludeWat Spirit Sites Sibounheuang in Gnommalath Tai, Wat Sen Sayalarm in Mahaxai Kang, Wat Sibounheuang in Oudomsouk, and Wat Sen Sayalarm In total 39 territorial spirit sites were identified, typically compris- in Nakai Neua. ing of a spirit hut located within a sacred forest. Twenty-nine other spirit sites were also identified, typically comprising unique natu- Cemeteries ral features such as groundwater springs, caves and grasslands. A total of 81 cemeteries were identified, of which 41 are located On the Nakai Plateau a number of the spirit sites identified are within or partially inside Project Lands and may be subject to land located inside or in close proximity to Project Lands, the most loss, 26 are located inside the inundation area, and one is located significant being ten territorial spirit (phi meuang) sites and two on the bank of the Xe Bang Fai.Twentyone cemeteries are located sacred salt licks (bor kua and bor sangtew). outside Project Lands and therefore should not be adversely In the Downstream Channel area eight territorial spirit sites were impacted by the Project. identified however all of these sites are located outside Project Landsanditisnotanticipatedthattheywillbeadverselyimpacted Other Cultural Sites Impacts by the Project. A number of other spirit sites are located inside A total of 26 other cultural sites were identified, most of which or in close proximity including Tham Bong, located at the Phou comprise of unique natural features such as groundwater springs Phathoung quarry site, and Tham Pha Thoung. or caves. Some of these sites are located inside or partially inside In the Impact Corridors, nine spirit sites including six territorial Project Lands and may be subject to loss of land. Further, there is spirit sites, were identified as being located inside or in close prox- the potential for the Project to increased access to these sites which, imity to Project Lands. There is potential for the spiritual amen- depending on how it is regulated, may have either positive or neg- ity of these sites to be adversely affected by the environmental impacts associated with construction activities and the potential ative impacts on the cultural amenity. loss of land along the Xe Bang Fai due to an increase in the rate Palaeontologic Sites of erosion during Project operation. One of the most significant Palaeontologic sites were identified including fossilised animal bones of Quaternary age in cave floor deposits in the Pha Phen / Phou Phako area and a marine fossil assemblage, including cri- noids and shells, within Carboniferous limestone in the same area. The Project activities are unlikely to have a significant impact on PCR at these sites. Plate 25: Archaeological site AS-2, Pha Phen Plate 26: Historical site HS-6, Kouan Ku 152 Physical Cultural Resources EAMP Main Text Impacts Figure 3.72: Plateau PCR Sites Impacts and increased rates of river bank erosion which could impact PCR During Project construction and operation there is potential for located on or close to the Xe Bang Fai. The improved access and PCR sites located within Project Lands to be either permanently or tourist potential of the area may result in impacts related to the temporarily disturbed, and for the amenity or PCR value of these increase influx of people to the area. sites to be adversely affected. The general impacts that may result Mitigation and Management from Project construction or operations are outlined below. The site specific impacts for each PCR, which are too numerous to dis- PCR Plan cuss here, are presented in the Annex P. Appropriate management and mitigation measures will be imple- Construction mented for all sites potentially impacted by the Project. NTPC has developed a PCRplan to address or minimise any adverse impacts Impacts associated with construction activities include loss of the Project may have on these PCR. Recommendations for the land, alteration of air quality, noise, vibration, aesthetic degrada- management of PCR are summarised in Table 3.75. Further details tion, change of water quality and restriction of access. PCR may of the specific activities, together with an identification of respon- also be adversely impacted due to the influx of construction work- sibilities are presented in Annex P. ers and associated in-migration. Potential impacts of this in-migra- tion include damage, deterioration and unacceptable exposure to Area Affected by Construction Activity historic sites, spirit sites, temples, and cemeteries. The locations of the PCR will be provided to the HC. The HC will berequestedtoreviewtheselocationsandmakeadjustmentstothe Operation Project design, where practical and possible, to minimize impacts The primary impact during operations will arise from inunda- and risks to identified PCR. tion of the Nakai Plateau which will result in the abandonment If disruption of known sites is considered unavoidable, permis- and loss of some PCR sites. PCR sites impacted by the inundation sion from GOL will be requested to implement the management include spirit sites and cemeteries. Increased pressure on land use strategy before any activity is undertaken with respect to the site of in the reselement areas, abuing the reservoir, may adversely concern. Aer gaining approval from the GOL, NTPC will imple- affect PCR aready present in these areas. Other impacts related to ment the management strategies. operations include restriction or loss of access to PCRby the physi- For sites that are identified outside a construction area, but are cal presence of Project infrastructure (e.g. Downstream Channel) in close proximity, those items may need to be visibly marked or Physical Cultural Resources 153 EAMP Main Text Plate 27: Spirit site, Phi Meuang Plate 28: Religeous site, TS-6, an abandoned temple active preservation measure such as fencing-off sites and reloca- · Stopping work and securing the areas adjacent to the objects tion of items may be undertaken. and sites of physical cultural resources to prevent damage to During construction it is recognized that new discoveries, or such objects and sites. "chance finds", of items or sites of physical cultural resources may Chance Finds Pocedure be found. To address this, the HC is required to prepare, as part of Achancefindsprocedurehasbeendevelopedtoassist,duringcon- the HCCEMMP, a Physical Cultural Resources Management Plan. struction activities, in the detection, reporting and prevention of The plan will include methodology for the following: damage to currently unidentified PCR. To facilitate the implemen- tation of the procedure, a Lao PCR specialist shall be deployed at Impacts · Documentation and identification of any known locations of any objects or sites of physical cultural resource (i.e. those sites strategic construction areas to (i) assist the HC in his identification of PCR; (ii) to report the findings to NTPC; and (iii) where appro- documented as part of the PCRS); priate, conduct the mitigation measures to ensure the safety of the · Notification to the construction workforce of the need to be PCR item, but at the same time, prevent any unnecessary delays in vigilant in the detection and reporting of, and the prevention construction. A diagram showing the activities of the chance finds of disturbance and damage to, objects and sites of physical cul- procedure is presented in Annex P. tural resource; Nakai Plateau- Not Affected by HC works · In relation to previously identified locations of objects and sites The Reselement Management Unit and Reselement Office will ofphysicalculturalresources,notificationoftheHC'sintention incorporate the PCR Survey results into the reselement pro- to commence construction activities at the locations should be gramme for those areas which are not related to the HC's construc- given to the NTPC at least 28 days prior to the disturbance of tion activities. Specifically, items of physical cultural resources such locations; value, such as village, temples, stupas and cemeteries will be relo- · Notification to the NTPC of any objects or sites of physical cul- cated to the new village or new buildings, if required. tural resources encounted by the HC within the construction During the reselement process chance finds, of items or sites of area; and physical cultural resources may be identified. Those working in Plate 29: Cemetery site C-34 Plate 30: Cultural site CS-24, Tham Phra 154 Physical Cultural Resources EAMP Main Text reselementactivities,especiallyinvolvinginfrastructuredevelop- Table 3.74 General mitigation measures of the PCR Plan. ment, will be required to stop work immediately if any new item is discovered during works. NTPC will then seek guidance from Mitigation Measures GOL, and the District Information and Culture Office and MIC to 1. Conduct an awareness program in advance of construction activities develop an appropriate management strategy. to prepare communities for the potential impacts on PCR sites and to identify further site specific mitigation measures. Xe Bang Fai Region ­ Not Affected by HC Works 2. Impacted PCR land and assets, most of which are communal, will be For those items identified along the banks of the Xe Bang Fai, mon- replaced, compensated or moved as identified. itoring will be undertaken during the Operating Phase. This will ensure that if any of these items are in danger of becoming affected 3. For spiritual and religious sites, compensation shall also include the provision of support for the conduct of `appeasement' ceremonies. by the Project, due to increases in river bank erosion, mitigation measures are implemented in a timely manner. 4. Ensure that movable PCR artefacts located in publicly accessible places (i.e. temples and rock shelters) are secured from theft and vandalism prior to the construction period, in a manner that does not adversely af- Pest Management Plan fect their religious / spiritual amenity. Activities in the Project area may lead to a proliferation in the 5. Give the communities primary responsibility, with support from NTPC and the MIC, for the relocation of movable structures such as stupas, and population of pests and a subsequent increase in the use of syn- burial urns since they have the required knowledge of local rituals and thetic chemicals, such as pesticides and herbicides, to control these procedures for moving such objects. pests. Any proliferation in pest population may be detrimental to 6. Engage a Lao PCR expert specialising in cultural anthropology to conduct both agricultural productivity and human health. The subsequent the community awareness programme, and to oversee mitigation meas- increase in the use of synthetic chemicals has the potential to cause ures where required. harm to the user, the public and the environment. To help address 7. Implement the Chance Find Procedure for all construction and resettle- this potential problem NTPC has developed a Pest Management ment activities. Plan (PMP). The aim of the PMP is to manage any potential pest 8. Engage a Lao PCR expert to work along side the Head Contractor. problems that may develop and help ensure that the use of all pesticides, herbicides, fertilizer and any other synthetic chemical 9. Ensure that all construction workers receive a PCR induction programme. associated with the Project, will be handled properly. The PMP is 10. No cave or rock-shelter area should be disturbed without conducting an Impacts based on an Integrated Pest Management (IPM) approach, which archaeological investigation, and if required, an archaeological salvage. promotes good agricultural practices through the use of respon- sible and sustainable activities that will result in the reduction in pesticide use. A summary of the PMP is outlined below, with a The Project intends to support the National Agriculture and For- detailed pest management plan being presented in Annex M for the following three areas: i) agriculture; ii) public health; and iii) estry Extension Service (NAFES) to implement an IPM training construction. Budgeting, scheduling and monitoring requirements programme through Farmer Field School (FFS) activities in geo- are included in the annex. graphical areas relevant to the Project. Farmers will be trained when to use pesticides and to use only the correct pesticides; at Agriculture the appropriate dose, at the right time, and not to pose a hazard to Baseline themselves, others or the environment. A Pest Management Specialist (PMS) and an agronomist will pro- In general, pest aack on agricultural crops and the use of pesti- cide in Lao PDRis low and rarely of economic importance. Current vide training for the reseled villagers on the Nakai Plateau and pests include: brown plant hopper (Nilaparvata lugens), stemborer authorise the use of pesticides and other synthetic chemicals. The (mainly Scirpophaga incertulas), gall midge (Orseolia oryzae), rice PMS will be trained in IMP and thus will be able to strengthen the bug (Leptocorisa oratorius), armyworm (probably Spodoptera mauri- capacity of NAFES to run IPM FFSs. tia acronyctoides), golden apple snail and brown spot disease (Coch- The use of organic fertilizer will be encouraged, especially on the liobolus miyabeanus, alt. Helminthosporium oryzae) (Morton, 2003). NakaiPlateau,tointroduceorganicmaerintothesoil.TheProject Although across the country very lile pesticide is used, the situa- has already established a compost plant on the Nakai Plateau to tion is changing, with the amount of insecticide use in rice having supply the pilot village. Although secondary to the importance probably doubled in the last five years (Heong et al. 2001). of organic fertilizer, careful choice and planned use of the correct Impacts inorganic fertilizer will also be essential for successful agriculture Improved access to the NNT NBCA will facilitate access for trad- on the Plateau. ers of synthetic chemicals. On the Nakai Plateau, as the reseled Pesticides Acceptable & Not Acceptable to the Project communities adopt more intensive agricultural practices there will Given the limited size of the market in Lao PDR, when pesticide be increased potential for pest aack, especially as the ecology of use is required the Project will adopt the registration and regula- the new crops finds a balance during the initial years. The poor tory systems of Thailand and Vietnam. Pesticides acceptable for state of the soil in the reselement area will require application of fertilizer, both organic and inorganic. Uncontrolled application of use where the Project has an influence must satisfy the following inorganic fertilizers could lead to contamination of the land and criteria: i) registered in Lao PDR and not on the Category I (WHO) reservoir. Increases in the amount of dry season irrigation along list; and/or ii) registered in Thailand, and/or iii) registered in Viet- the Xe Bang Fai, a consequence of the additional Project discharge, nam; and iv) not banned in Lao PDR. Approximately sixty pesti- has the potential to cause a proliferation in the number of pests, cides have been banned or subjected to restrictions throughout the which may subsequently lead to reliance on pesticide to control world. Table 3.75 indicates the active ingredients with restrictions outbreaks. in Asia/Pacific countries and those banned in Lao PDR. These pes- ticides are not acceptable for use in Project activities. Regulatory Mitigation control of synthetic chemicals in the NNT NBCAshall prevent any Integrated Pest Management adverse impact. Pest Management Plan 155 EAMP Main Text Table 3.75: Active ingedients not acceptable to NTPC Active Ingredients with Restriction in Asia/Pacific Countries Active Ingredients Banned In Lao PDR Active Ingredients on the PIC List But Not Banned in Lao PDR Active Ingredient Country placing a restriction Active Ingredient Status Active Ingredient Status Aramite Thailand 2,4,5-T X DNOC (X) Scheduled for PIC review Azinphos-ethyl Thailand Aldrin X Methamidophos Xf Azinphos-methyl Thailand Binapacryl X Pentachlorophenol X Calcium arsenate Thailand Captafol X Phosphamidon Xf Chlordecone Thailand Chlordane X Benomyl powder formulations >7% scheduled for PIC review Chlorthiophos Thailand Chlordimeform X Carbofuran powder formulations >10% scheduled for PIC review Cycloheximide Thailand Chlorobenzilate X Thiram powder formulations >15% scheduled for PIC review Dichlorophen Thailand Cyhexatin ! Demefox Thailand Daminozide ! Demephion Thailand DDT X Dinoterb Thailand Dieldrin X Disulfoton Thailand Dinoseb X DNOC Thailand Endrin X Endosulfan Thailand Ethylene Dibromide X Fensulfothion Thailand Ethylene Dichloride X Folpet Malaysia Ethylene Oxide X Fonofos Thailand Fluoroacetamide X MCPA Thailand Gamma HCH X MCPB Thailand Heptachlor X Mecoprop Thailand Hexachlorobenzene X Mephospholan Thailand Leptophos ! Methamidophos Thailand MEMC ? Impacts Methazole Australia Methyl Bromide ! Mevinphos Thailand Monocrotophos Xf Mirex Thailand and others Parathion Xf Paraquat Malaysia Parathion Methyl Xf Paris Green Thailand Sodium Arsenate X Phorate Thailand Sodium Chlorate ! Phosphamidon Thailand Sodium Fluuroacetate ! Prothoate Thailand TEPP ! Schradan Thailand Toxaphene X Sulfotep Thailand Tribufos Australia Notes: "X" = not registered in OECD countries and on the FAO/UNDP Prior Informed Consent (PIC) List; "Xf" = formulations subject to restriction and not the active ingredient; "?" = banned but with unknown PIC status; "!" = poses risk to handlers, environment, in the treated produce and is subject to regulatory restriction in some countries. Public Health prior to 2002, included Khammouane and the districts of Nakai, Gnommalat, Mahaxai and Thakhek. The prime means of control- Baseline ling malaria in Lao PDR is the use of bed nets. Levels of human Current diseases and their vectors that have been identified as infection have dropped dramatically since treated bed nets (IBN) important for the Project area include: dengue, malaria, Japanese were introduced in 1998 along with a campaign for Early Diagno- encephalitis, Opisthorchiasis and Schistosomiasis. sis and Treatment. For management of dengue, education programmes promote the Japanese encephalitis is endemic in most rural areas of Asia. Its need to minimize standing water, the habitat preferred by the lar- presence has been indicated in Khammouane Province, though val stage of the Aedes aegypti mosquito vector. Larvicidal chemicals the extent is not known (Vongsay et al. 1994). Although the main tocontrolthevectormosquitosuchastemephos(Abateinsecticide) vector mosquito, Culex tritaeniorhynchus, is common, only a small are added to standing water, and adulticidal sprays of malathion fraction are infected. There is no specific treatment for infected or a synthetic pyrethroid are applied in houses. individuals but general viral vaccines give short-lived protection. With regards to malaria, the level of Plasmodium infected mosqui- Preventing mosquito bites around dawn and dusk is effective in toes, Anopheles dirus, A. minimus and A. nivipes, in the entire Project avoiding the disease. area is not known but must be low. Current levels of human infec- This liver fluke, Opisthorchis viverrini, is picked up through eating tion are very low on the Nakai Plateau (< 0.6% Khammouane Prov- infected raw fish and the residents of Gnommalat and Mahaxai are ince, Dept. of Health) and also in the Gnommalat, Mahaxai, and commonly infected. The intermediate host is the snail Bithynia sia- Xe Bang Fai Districts. A Lao-EC project that ran for several years mensis goniomphalus, and a survey has identified infected snails in 156 Pest Management Plan EAMP Main Text the area affected by the Project area, specifically in the Gnommalat Construction workers will be educated in the same prevention District (Lohachit, 1997). measures currently used by the local communities. Workers will Schistosoma mekongi, a blood fluke, is only recorded around Kong also be supplied with bed nets which will help prevent the preva- Island in the south of Lao PDR. The intermediate host is the snail lence of mosquito borne diseases. Certain amounts of pesticides Neotrichula aperta gamma race and a survey has identified this snail will be purchased to treat the bed nets, but the insecticides in use in the area affected by the Project area, specifically in Ban Nakio (synthetic pyrethroids) are of very low mammalian toxicity and and Ban Mahaxai. However these individuals were not infected there should be no danger to human health. (Lohachit, 1997). Construction Impacts The Project will likely increase the number of breeding sites for the Baseline mosquito vectors of dengue, malaria and Japanese encephalitis, The areas for the Pilot Village and the Theun Douane Demonstra- through increases in irrigation in the Project area and the reser- tion Farm on the Nakai Plateau have already been cleared of veg- voir itself. Although the Project will result in an increase in these etation utilising physical means only ­ no herbicides were used. habitats, there should be no significant impact on the prevalence of these diseases as long as the currently successful prevention meas- Impacts ures against the vectors continued to be adopted. During Project construction, land will be cleared of vegetation to Raw fish sauce may contain the disease Opisthorchiasis, and local facilitate building activities. Routine maintenance of the Transmis- communities and construction workers could be at risk from infec- sionLineswillrequireperiodicremovalofanyvegetationthatmay tion if they consume it. This is not different from the current situa- pose a danger during the operation phase. Any inappropriate use tion and not a direct impact from the Project. of herbicides to clear vegetation is likely to cause contamination of Although the uninfected snail vector is found in the Project area, the land and nearby water bodies. Inappropriate use and storage Schistosomiasis is not recorded. In the opinion of local specialists, of these synthetic chemicals may also cause harm to the users. there is no reason to believe the Project will have any impact on the spread of this disease. Mitigation Impacts Mitigation No chemical use is permied for clearance of the reselement area Through its reselers' health programme and regional health for the new villages, nor is the need envisaged. The reseled com- programme, the Project will support local clinics and small hos- munitieswillparticipateinthepreparationoftheirownland,clear- pitals on the Nakai Plateau and Xe Bang Fai area in continuing ingtreesandundergrowthinthemanualmannertowhichtheyare the already successful education of the population in prevention accustomed. The initial clearance of Project lands, such as for the of dengue, malaria and Japanese encephalitis. This education pro- Transmission Lines, will be done using physical means only. Main- gramme will also include disseminating information on the dan- tenance of land under power lines in the existing Theun Hinboun gers of eating raw fish and the prevention of Schistosomiasis. Such hydroelectricprojectisthroughtheuseoflabourandtheProjectwill support and reinforcement of local medical facilities in providing adopt the same methods. Certain situations may dictate occasional preventative measures has been found to be lacking in schemes use of herbicides, and to prepare for this appropriate herbicides elsewhere in the world, and is now considered an essential prereq- maybeidentifiedbeforehandusingtheselectioncriteriadetailedin uisite to international funding (Hunter J.M., in Sharp D., 2003). Annex M. Pest Management Plan 157 EAMP Main Text Impacts 158 Pest Management Plan EAMP Main Text 4. Assessment of Social Issues Nakai ­ Nam Theun NBCA 160 Baseline 160 Impacts 160 Mitigation & Management 160 Nakai Plateau & Downstream of the Nakai Dam 161 Baseline 161 Impacts 163 Mitigation & Management 163 Xe Bang Fai 165 Baseline 165 Impacts 167 Mitigation, Management & Monitoring 167 Nam Kathang 168 Baseline 168 Impacts 168 Mitigation 168 Project Lands 168 Baseline 168 Impacts 168 Mitigation & Management 168 Monitoring 169 Internal Monitoring 169 External Monitoring 169 Grievance Procedure 169 Enhancement of Capacity 169 Social Issues T he following chapter presents a summary of the social con- text, social impacts and the integration of the social miti- gation and management measures into the Project design. The social issues are presented by geographical location, which include: i) the NNT NBCA; ii) the Nakai Plateau and downstream of the Nakai Dam site; iii) the Xe Bang Fai; and iv) Project Lands. This chapter is based on the social components of two documents: i) the Social Development Plan (SDP); and ii) the Social and Envi- ronmental Management Framework and Operational Plan (SEM- FOP). Further details for any of the issues discussed below are pro- vided in either the SDP or the SEMFOP. Assessment of Social Issues 159 EAMP Main Text Nakai ­ Nam Theun NBCA Public Health Sustained health care is lacking, with malaria, respiratory diseases Baseline and gastro-intestinal diseases found throughout the NNT NBCA. People & Population Drinking water is rarely boiled and general sanitation is poor. Most people rely on local ritual specialists for cures based on a The population in the NNT NBCA is approximately 5,800, repre- combination of spiritual intervention and herbal medicines (SEM- senting 1,092 families in some 31 villages (SEMFOP, 2003). This FOP, 2003). The nearest clinics and small hospitals are located in population is growing fast, with more than 70% of the villages Ban Lak Sao and Ban Oudomsouk. experiencing a population growth rate (4%) greater than the 1995 national average of 2.4%. Since 1975, security, combined with Impacts increased provision of services and penetration of traders, have Although there is no direct impact by the Project, there are likely increased average longevity while birth rates remain at their previ- to be significant social implications for the communities of the ous high levels. NNT NBCA. The inundation of the Nakai Reservoir will improve This indigenous population is of diverse ethnic composition, com- access into and out of the NNT NBCA, providing the potential for prising of three main ethno-linguistic groups: i) Brou (53%); ii) easier logging and poaching, but also improving access to outside Vietic (25%); and iii) Tai Kadai (including the Sek) (16%). These products, markets and health facilities for the area's communities. various groups have been in contact with each other over a long The influx of labourers will provide a potential market for the period of time, and there is considerable interaction between the agricultural products, wildlife and other NTFPs. However, current various groups, especially between the Brou and the Vietic groups resource utilisation in the NNT NBCA is not sustainable in terms of the NNT NBCA with the Bo and Brou communities on the Pla- of conservation management or the long-term needs of a growing teau. Intermarriage andsharedculturalcharacteristicsexistamong population. Therefore the increased pressure of supplying con- these groups, but there is not the melting pot culture of the Nakai struction workers, if not properly managed, will have a negative Plateau, due to its relative isolation. impact on both biodiversity and land use. Livelihoods & Income Communities residing in the NNT NBCA have the potential to impact the operations of the Project. Increases in inappropriate Livelihood activities in the NNT NBCA include shiing cultiva- landuseactivitieswouldresultingreatersedimentationratesinthe tion, livestock raising, hunting, fishing and gathering non timber Nakai Reservoir and thereby reduce the lifespan of the Project. forest products (NTFPs), as well as sedentary cultivation. Ethnic groups have borrowed livelihood practices from each other and Mitigation & Management have demonstrated adaptability to their environment. The Project will provide US$ 31.5 million of financial assistance Upland rice production is practiced on about 350 ha each year. and management support for the conservation of biodiversity and However, most households are able to grow rice for sustainable improvement of livelihoods for the communities residing within consumption for only two to six months per year. Like the Plateau the NNT NBCA. GOLis developing a management plan, the SEM- communities, NNT NBCA communities have turned increasingly FOP, for the NNT NBCA with the objectives of effectively protect- to commercial activities such as marketable NTFPs, livestock and ing the watershed, wildlife and biodiversity values; safeguarding fish. They sell the surplus for cash to buy rice and manufactured the well being, traditional livelihoods and culture of its human items such as clothing, household utensils, etc. inhabitants; and improving livelihoods by focusing on poverty Issues Data on cash income indicates some differences between Plateau reduction through environmentally sustainable development. The and NNT NBCAcommunities. In 1996, the average annual house- funds will be administered by the WMPA. hold cash income for NNT NBCA communities was only US$ 87 (CARE, 1996). Trade of forest and agricultural products formed the Livelihood Options & Community Development Social major source of cash income for NNT NBCA villages, at 44% and TheSEMFOPwillintroducelivelihooddevelopment,aimedatpro- 38% respectively. Fish and livestock were also sold for cash. moting biodiversity conservation by increasing food production, Infrastructure diversifying livelihood options and gradually intensifying land use, thereby reducing reliance on hunting, resource extraction and The NNT NBCA is remote and access into and within is diffi- shiing cultivation. Implementation consists of an approach based cult, especially in the wet season. Access is limited to footpaths on interventions such as: i) domestication of NTFPs; ii) multi-spe- (although two 3m-wide tracks have recently been constructed) and cies agroforestry, incorporating fruit trees; iii) livestock improve- river transportation, which varies seasonally. ments and veterinary care; iv) enrichment of fallows, use of green There are virtually no formal markets in the NNT NBCA, however, manure, contour bunds, terracing; v) paddy development; vi) some people have begun to sell consumer goods in front of their improved market access for cash crops; vii) improved rice storage homes. Along the Nam Noy and the Nam Pheo, itinerant Viet- facilities; viii) sustainable riverine fisheries, and possibly aquacul- namese traders sell household goods for cash or barter for NTFPs, ture; and ix) community forest management, and employment in mostly wildlife and plant products (raan cane, damar resin, car- biodiversity conservation and eco-tourism. damom, and wild honey). Community infrastructure will be improved, supported in the Education first four years by the Japan Social Development Fund Grant. Improved access to markets and services will include river trans- The only three primary schools in the NNT NBCA are located in portation and some paths and tracks. Health interventions include Ban Na Vang, Ban Teung, and Ban Na Meu/Na Meo. These are impregnated mosquito nets, improved maternal and child health simple one-room structures which teach one or two grades. The care, information on improved nutrition and hygiene, immunisa- teachers are paid irregularly by GOL and receive supplements tion programmes, training of village paramedics, establishment from the villagers. School improvement plans have been carried of medicine revolving funds and regular visits by medical teams. out in a number of villages as part of the District Upland Develop- Education interventions consist of restoring and improving exist- ment and Conservation Project (SEMFOP, 2003). ing school buildings, supplementing regular teachers'salaries and 160 Nakai - Nam Theun NBCA EAMP Main Text training teachers to conduct non-formal literacy classes for adults, Nakai Plateau & Downstream of the Nakai provision of teaching equipment and books, and an adult literacy programme. Dam Activity Framework Baseline Under the SEMFOP, the three main technical NBCA management activities that will mitigate and manage any impacts are i) Forest People & Population and Land Use Planning, Allocation and Management (FLUPAM); Approximately 5,684 persons, representing 1,030 households in 17 ii) Participatory Protected Area Management (PPAM); and iii) villages, reside in the inundation area of the Nakai Reservoir.As is Livelihood Development for Conservation (LDC). An outline of typical in very underdeveloped areas, over 50% of the population these activities is provided below, with further details presented is below 19 years of age. in the SEMFOP. The population can be classified into five main ethno-linguistic Forest & Land Use Planning, Allocation & Management groups: i) Brou (or Makong) (40%); ii) Tai Bo (40%); iii) Upland Tai groups (11%); iv) Vietic groups (6%); and v) a few members of FLUPAM is a participatory process of resource management the Sek ethno-linguistic group (1%). However, with the area being planning, aimed at ensuring equitable access to forest and land subjected to numerous inward and outward migrations over the resources and providing the basis for their sustainable manage- last 200 years, the distinctions between ethnic groups have become mentbylocalcommunities.Itwillencouragecommunitiestomake less clearly defined. The ethnic situation is further complicated their own decisions about sustainable natural resources manage- by intermarriage and a shared culture. Most of the original dis- ment, and provide villagers with the skills to solve problems. tinguishing features of the ethnic minorities such as language, FLUPAM will promote inter-village cooperation to solve resource material culture, house design and ritual practice have merged use conflicts and create linkages and networks between villages (RAP, 2003). to facilitate mutual support and cooperation for both conservation Although a "melting pot" of cultures exists, there are several char- and community development. Activities will integrate conserva- acteristics that qualify the original population as "indigenous". tion with development, whereby villagers are compensated for According to the World Bank OD 4.20, these include: i) a definite curtailing certain resource use practices by government assistance sense of belonging to the Nakai Plateau; ii) the fact that people on with livelihood development activities. Teams will be made up of the Nakai Plateau are economically disadvantaged; and iii) a pri- land use planners, conservationists, agriculturists, gender special- marily subsistence-oriented livelihood production system. ists and district officials who work with villagers in an interdisci- Livelihoods & Income plinary manner. Agricultural Production Participatory Protected Area Management Communities have traditionally cultivated rice, hunted and fished, PPAM recognises villagers as equal partners in the management of raised livestock, and gathered plant products, mainly for house- the protected area, and gives all stakeholders an integral role in the hold use. In recent years, increases in population, problems with planning and management by ensuring villagers have a focal role cultivation,andexposuretocashcommodities havespawnedmore in the: i) definition of boundaries and zones; ii) development of intensive and extensive exploitation of the forest for its marketable Social rules and regulations guiding resource utilisation; iii) implemen- products. The shi from an almost entirely subsistence economy tation of such regulations and management procedures. PPAM is to a more commercial one is being largely caused by immigrants, consistent with the GOL policy of transferring rights and respon- some engaged in logging activities and some in search of other Issues sibilities regarding land and forest use and management to local economic benefits. These people generate a buying market for villagers. PPAM aims to instil in villagers a sense of pride in and items such as vegetables, meat and forest products. co-ownership of the protected area, along with a real understand- Nevertheless, agriculture still dominates the economy with wet- ing of and support for biodiversity conservation. season rice the main agricultural crop. In 2002, the total cultivated Aer participatory planning and collection of data, the implemen- areaonthePlateauwasapproximately700ha,withriceaccounting tation of the PPAM will include: i) sustainable forest product uti- for about 80%. Paddy rice is not a large contributor to total produc- lisation and management (wood, NTFPs, etc.); ii) forest use rules tion (less than 20%) due to the low yields under rainfed conditions. and regulations; iii) joint monitoring, patrolling and enforcement; Upland rice production also continues to decline because of poor iv) cooperative activities through the village network; v) extension soils, adverse weather conditions and lack of modern technology. activities; and vi) modifications to rules, regulations and bounda- Soils are heavily leached, susceptible to erosion, of low pH and ries as required. low organic maer content with poor buffering capacities. As a result, only 17% of families are able to produce sufficient rice for Livelihood Development for Conservation a full year, while at least 50% of families have a rice deficiency for more than six months. Vegetables are mainly grown on swidden The LDC approach is a participatory process to identify appro- fields close to the homestead, in garden plots next to the house, or priate livelihood development activities within the context of along riverbanks. conservation. The process identifies major problems facing the community, and how they impact on the natural environment. Fish Development options are then reviewed, and proposed activities Aer rice, fish is the most important item in the diet. Fish are are prioritized. Each activity is then analysed, using Conservation caught mainly for household consumption and usually not sold on ImpactAssessmentprocedures,toassessthepotential positiveand a regular basis. Fish catch techniques vary with season, but villag- negative impacts on conservation. By this means, villagers begin to ers may have to to supplement their catch with dried or fermented recognise the interactions of their livelihood activities with biodi- fish in the dry season. versity and can modify their plans to reduce negative impacts and Men usually fish with cast nets in rapids or by deep-water gill nets. maximize positive ones. Children and women make an important contribution by search- Nakai Plateau & Downstream of the Nakai Dam 161 EAMP Main Text ing the banks and shallows for frogs, aquatic insects and small fish Education that supplement the family's diet. In theory, each village should have its own primary school, but Livestock & Poultry only in the larger villages (Ban Done, Ban Boua Ma, Ban Nakai Tai Livestock sales are the main cash source for buying rice and other and Ban Thalang) are they functioning properly. Some schools are commodities, estimated at just less than 50% of the annual cash financed by the villagers themselves since the local government income for households in the Project area (NTEC, 1999). The total has neither the funds nor can provide the teachers. Aendance is number of buffalo in the villages to be reseled is 4,100 head, with low, either due to the need for children to support their families average ownership of 4.7 per household. However, the actual dis- economically or to teachers not conducting classes regularly. tribution is distorted with some households owning over 30-40 Only a small percentage of villagers are literate in the Lao lan- (and up to 90) individuals, and a significant proportion not own- guage and none of the ethnic minorities languages of the Plateau ing any. are wrien. Except for a few women, who are mostly located in Taking into account all possible grazing areas, stocking rates could Ban Oudomsouk and roadside villages or are recent arrivals from potentiallybeaslowasoneanimalto20ha,butarecurrentlymuch downstream areas, the majority of women are illiterate. Literacy higher due to the way each herd is managed at the village level. level for men is only slightly higher. Sixty-three percent of people on the Plateau reported no schooling at all, while only 31% had Average ownership of pigs is reported to be six head per house- aended primary school. hold.Pigsareownedbymosthouseholds,mainlytorecyclewastes Many labourers and recent male migrants are literate. Several vil- and as a sideline income generating activity, but also for slaughter lage leaders were originally from outside the Plateau (Lao Loum for household consumption and use on ceremonial occasions. areas), showing that literacy can lead to positions of influence and Chickens of local breed are owned by almost all households, with power in the village (RAP, 2003). an average ownership of 15 per household. They are kept for sale, for household consumption and for use on ceremonial occasions. Public Health Non-Timber Forest Products Health statistics for the communities to be reseled on the Nakai Plateau were collected as part of the socio-economic survey con- NTFPs are an important source of supplemental income. Recent ducted in 1998. The main causes of death recorded were "fever" over-harvesting of damar resin, fragrant bark and other prod- and "malaria", accounting for nearly 50% of mortality cases in ucts has made these activities more time-consuming and resulted 1997-98. Other prominent causes mentioned by villagers were in incursions into the adjacent protected areas. This makes the diarrhea and respiratory infections. Two hundred and thirty-two exchange of NTFPs for rice more difficult and thereby threatens people reported having had malaria in 1998. However, the Lao EU food security. Malaria Control Project has achieved very good results in signifi- NTFPs account for approximately 12% of overall cash income, cantly reducing the incidence of malaria on the Nakai Plateau. The and carry an imputed value of approximately 2% of products percentage of patients testing positive at the Nakai District hospi- consumed in the household. NTFPs are especially important in tal dropped from 38% in 1996 to 1.8% in 2001. terms of cash for those villages on the edge of the forest. From 1996 to 1997, harvesting of damar resin increased from 17 to 80 tons, becoming one of the most valuable products. In the same period, the harvesting of bong bark decreased from 50 to 22 tons, either Issues because priority has been given to collecting damar resin or avail- ability has declined. The situation with raan is less clear while cardamom harvesting remains stable (RAP, 2003). Social Income In 1996, the annual average household cash income for the 16 vil- lages investigated was US$ 225 (CARE, 1996). Roughly half of total income is in cash (including 20% from agriculture and livestock, 10% from wages), and the other half from imputed income (includ- ing 30% from rice production,10%fromagriculture) (CARE,1996). In 1998, the average household total income of US$ 450 is well below the national poverty line of US$ 750 (RMU, 1998). Infrastructure Recently built electricity transmission lines run from Thakhek to Ban Oudomsouk. However, most households on the Plateau are without electricity and the more wealthy households use baer- ies. On the Plateau, 5% of households use covered wells while 35% use uncovered ones, and 60% of the population indicated rivers and streams as their only source of domestic water. As in the NNT NBCA, boiling water before drinking is not common on the Pla- teau (RAP, 2003). In terms of road infrastructure, Road 8b is an unsealed road of poor quality, especially as it ascends the escarpment and crosses Plate 31: Nam Theun between the Nakai Dam site and the confluence with the Plateau to the Ban Nam Nian area. the Nam Phao 162 Nakai Plateau & Downstream of the Nakai Dam EAMP Main Text Table 4.1: Resettlers preferences considered in the selection of prospective resettlement sites. Factors Details Agricultural considerations · Water supply must be accessible from the reservoir, along with an elevated site for the header tank to allow gravity irrigation to farm plots; · Slope for the farm plot area(s) should be as gentle as possible and ideally not exceed 15%; · The soils selected must be capable of providing adequate returns with a potential for the production of paddy wherever possible; and · All farm plots should form one contiguous land area wherever possible. Social considerations · The resettlement sites should be as near as possible to the old village location; and · Social and cultural factors must be taken into account including the village spiritual areas and customary boundaries. Resource considerations · Roads or other transportation infrastructure must be sufficiently accessible to ensure access to markets and other support services; and · Access to the reservoir, drawdown zone, forest and grazing areas should be convenient. In the three districts of Mahaxai, Gnommalat and Nakai the popu- shelters. People from villages along Road 8b between Ban Kham lation is served by one district level hospital and four to five health Keut and Ban Lak Sao use the river to fish. centres in each district. The ratio of medical doctors to popula- tion within Khammouane Province was one for 4,800 persons in Impacts 2001 (RAP, 2003). Although some health facilities exist, they are Nakai Plateau frequently incompletely staffed and poorly stocked with essential drugs. Most villages have a designated Village Health Volunteer The key social impact of the Project will be the reselement, due (VHV), but the volunteer seldom has the necessary medicines and to the creation of the Nakai Reservoir, of approximately 5,684 per- most need technical strengthening. On the Plateau, the average sons from 1,030 households in 17 villages, 15 of which will be fully distance to the nearest hospital (located at Ban Oudomsouk) is relocated. 11 km, and for most this is only accessible by walking. Only 3.9% The communities on the Plateau will also be impacted by construc- reported visiting a doctor in 1998. tion activities on Project Lands, such as the Nakai Dam, Headrace Channel, Intake Structure, construction of the relocated section of Nam Theun Downstream of the Nakai Dam Road 8b, and some tunnel works. The impacts and mitigation of The entire reach of the Nam Theun, from the Nakai Dam site to the construction activities are discussed in subsequent sections the headpond of the Theun-Hinboun Hydroelectric Project, is not below. cultivated. Between the dam site and Ban Katok (the first village, The main potential public health problems are related to the influx 50 km downstream), the Nam Theun is a succession of rapids and of large groups of construction workers rather than the impact of pools (Gondouin, 1996). In fact, the first reach of about 12 km to the reservoir. HIV/AIDS is identified as a possible problem. High- where the Nam Phao flows into the Nam Theun, has no permanent risk groups are perceived to be mobile work-forces such as con- struction workers, truck drivers, bar hostesses and those involved in the sex industry. It is expected that there could be an increase in traffic related and Social other accidents once the Project starts construction. In the long term, with the continued introduction of adequate pub- lic health measures, no significant effects are expected on the prev- Issues alenceofmalariaandothermosquito-bornediseases.Althoughthe number of breeding sites may increase, the continued implementa- tion of protection measures will help ensure that the prevalence of malaria is maintained at its current low levels. Nam Theun Below the Nakai Dam Downstream of the Nakai Dam and up to the confluence of the Nam Theun with the Nam Phao, the Nam Theun will be subject to environmental changes as a consequence of significantly reduced flows. There are no permanent villages along this stretch of river, principally because the topographical features make access diffi- cult. It is known that there are fishermen and hunters using this stretch of river. It is also known from surveys and interviews that the value of the catch is small, no more than a few thousand dollars per year in total cash and imputed value. Mitigation & Management Reduction of Resettlement Numerous alternative options have been examined to minimize the number of villages requiring reselement, including the lower- ing of the reservoir FSL. As most of the population on the Plateau resides along the river, just above the normal flood level of El 525 m, FSL has to be reduced to about this height before the number Plate 32: Nam Theun between the Nam Phao and Nam Gnouang of people to be reseled drops significantly. Such a change renders Nakai Plateau & Downstream of the Nakai Dam 163 EAMP Main Text the Project uneconomic because of the reduction in storage volume and wells for drinking water will also be provided. Electricity will and therefore power generation. be supplied to houses and an all-weather road will run through Resettlement Action Plan the reselement area. Each family will be provided with 0.5 ha of cleared land for vegetable gardens, fruit trees and housing. Tools, NTPC has developed a management plan, the RAP, for the resele- seedlings, and other essentials will also be provided.All these pro- ment of the eligible Nakai communities. The plan allows for imple- visions are set out and budgeted for in the Concession Agreement mentation of a range of replacement and livelihood programmes (2002) and the RAP (2003). and asset compensation activities. Importance has been aached to integrating indigenous practices that are currently being carried The reseled people will have the choice of a range of supplemen- out by villages. tary livelihood activities in which the Project will fully support them, including irrigated agriculture, commercial forestry, reser- Reselement Sites voir fisheries and livestock husbandry. All reselement villages Aer initial assessment, potential reselement areas were identi- will not be of any lower standard than the current pilot village. The fied that included the Nakai Plateau and Gnommalat District. Pub- following combination of enterprises for reselement households lic consultations and participatory activities with the communities has been selected based on studies and evaluations of the natural demonstrated a very strong preference, with few exceptions, to resource base by specialists in forestry, agronomy, agricultural eco- remain on the Plateau rather than move to lowland areas. Table 4.1 nomics and reservoir fisheries. The strategy also takes into account presents factors indicated as important to villagers when decid- the socio-economic and cultural background of the people and the ing on their reselement preferences. These factors were taken into economic environment in which they will be operating. The main account in the choice of potential sites. aspects of the livelihood model are: In 2003, an assessment identified more specific sites located along · Specific sites for irrigated cropping with priority for rice pro- the south-western shoreline of the reservoir, providing water for duction as well as vegetable gardens and forage plots. The irrigation, and easy access to the drawdown zone, grazing and for- development will also rely on: i) improvement of soil fertility; est land.Asignificant proportion of the land has slopes below 15%, ii) cultivation of cash crops; iii) improving access to credit; and suitable for village sites and the establishment of individual farm iv) institutional support through government organisation plots. The majority of these potential reselement sites fall within existing village customary use areas. The locations of potential · Introduction of the growing of forage for large livestock com- sites for the reselement villages are shown in Figure 3.58. bined with drawdown grazing and controlled under-forest grazing. This should support the current levels of large live- Infrastructure stock. There is also considerable potential to increase yields The Project will provide each village with improved infrastructure from small livestock with beer animal health control. including housing, electricity, domestic water supply, irrigated · Forestry resources (of up to 13,750 ha). This will provide vil- water supply, irrigation system, schools and kindergartens, clinics lagers with a base source of income and will be the safety-net and other community infrastructure.Atransformer with sufficient occupation of the Plateau householders. capacity to provide a 20 MW local electricity supply will be located · A productive reservoir for fishery with the RAP (2002) assum- at the power station. This will facilitate the use of electric irriga- ing an actual annual catch of 350 tonnes per year. This allows tion pumps instead of the current diesel pumps and will provide a for 250 tonnes being sold and 100 tonnes for household con- more economical, convenient and reliable water supply. sumption, which is greater than the current consumption. This Issues The Project will upgrade and construct new sections of Road 8b development will be supported through the "Preliminary Res- on the Plateau, and provide access to all reseled villages. The ervoir Fisheries Management Plan" (PRFMP); and improvements made to roads are discussed in Chapter 3. · An estimated 400 person-years of labour that will be available during the construction period and approximately 100 jobs Social Livelihood Options aer completion in activities such as floating log removal from NTPC will be responsible for the installation, operation and main- the Nakai Reservoir and general outdoor maintenance (RAP tenance of a reliable pumped water supply to the reseled villages, 2002). Plate 33: General layout of the Pilot Village showing house locations, farm Plate 34: A comparison of Pilot Village housing (left) with the current stand- plots and the irrigation reservoir. ard on the Nakai Plateau (right) 164 Nakai Plateau & Downstream of the Nakai Dam EAMP Main Text Households will be supported with basic food by the Project until Xe Bang Fai incomes reach acceptable levels. It is conservatively predicted that full income potential will be achieved aer eight to nine years fol- Baseline lowing reselement. Given the nature of the land, it is clear that forestry and fisheries will provide the most sustainable income. People & Population The projected income target is US$ 1,200 (2002 value) per house- Unlike the Nakai Plateau, the downstream communities consist of hold, an increase of more than 160% above the current situation Lao Loum and Lao Theung groups. and well above the Lao PDR poverty line of US$ 750. Application of the World Bank OD 4.20 indicates that the Lao Anumber of possible risks which could affect the realisation of the Loum groups (Lao, Phou Thai, Lao Kaleung and other Tai groups) incomes predicted above have been identified. The most effective do not qualify as ethnic minorities, due to their lack of collective risk mitigation measure is the allocation of sufficient forest area property, the presence of institutions that are integrated into the formal political system, exposure to market economics, Lao or to have a reserve for use in lean years. The second risk mitigation similar language to Lao and identification with the main official measure is the provision of basic skills and resources to the reset- category of Lao Loum. tled communities so they develop capacity and flexibility to adjust The Lao Theung groups (Brou or Makong, Khamu and other small to changing circumstances. groups) exhibit considerable degrees of assimilation in relation Pilot Village to the dominant lowland culture but, nevertheless, have retained someethnicminoritycharacteristics,includinglessintegrationinto The objective of establishing a Pilot Village to be moved in advance market place economics and some degree of ethnic language and of the others is to provide an opportunity to test assumptions, ver- self-identity. However, it should be pointed out that many Brou ify predictions and work out solutions to problems in advance of groups strive to identify themselves with the dominant culture and the main relocation. there are no taboos against inter-marriages or co-habitation in the same village. The situation is fluid and all indications point to a The three hamlets of Ban Nong Boua, Ban Sailom and Ban Paman- merging with the dominant culture. ton were selected for relocation as a Pilot Village. Planning for the Along the upstream of the Upper Xe Bang Fai a total of 537 house- establishment and relocation to the Pilot Village commenced in holds are present in twelve villages. The two main groups repre- 2000 and relocation began in early 2002. Actual relocation of the sented are the Kaleung (36%) and the Brou (61%). In the Upper three hamlets was completed in mid 2003 aer house construction Xe Bang Fai a total of 852 households are present in twelve vil- and completion of the necessary infrastructure (roads and electric- lages, 75% of which are Tai Lao, and 10% Brou. The twelve vil- ity). lages located on the Middle Xe Bang Fai have a total of 668 house- holds, 56% of which are Phou Thai, 37% Tai Lao, and 5% Brou. The Valuable experience has been gained from the Pilot Village relo- Lower Xe Bang Fai is characterised by densely seled agricultural cation, and has been used to modify future plans for the main areas within the floodplain (53 villages, 5,003 households). Ethnic reselement process. Ongoing development and support is being groups in this region consist of lowland Lao (52%) and Phu Thai provided, and further lessons are expected to be generated. The (41%), with small enclaves of Upland Tai (2%) and Khamu (4%) Social major lessons learned to date relate to topographical and soil sur- (RAP 2003). veys, size and location of paddy land aributed to each household, Livelihoods structure of the villages, and design and construction of the irri- Issues gation system. In addition, it should be noted that the consolida- Agricultural Production tion of disparate villages from different ethnic groups into a single Food security in the lowlands is less of an issue in terms of crop community has not posed any problems. production. The key to improving the economic situation of the region lies in increasing agricultural productivity, and GOL Reselers Health Plan has embarked on a major programme of irrigation develop- The Project will fund a health programme for the benefit of the ment along the Xe Bang Fai. Currently, only 14 of the 89 villages reseled people to compensate for any non-mitigatable adverse along the whole of the Xe Bang Fai do not have irrigation pumps health effects. Health monitoring will take place twice per year per (RAP, 2003). Although most of the pumps are electric, 14 run on diesel, which is inefficient and costly. In addition, some of the die- person in all reseled communities. The health programme will sel pumps are also in bad repair, with the result that the total irri- follow GOLnational and provincial policies and targets and, in the gation potential of even currently installed pumps and systems is long term, combine health care activities with GOL provincial and not fully utilised. country-wide programmes. The total area of developed paddy in the 89 Xe Bang Fai villages is Regarding AIDS, there will be concentrated campaigns (and avail- about 14,120 ha, of which 10,536 ha are used for wet season paddy, ability of condoms) for the resident rural and town communities and 5,306 ha for dry season paddy, with about 3,840 used for both as well as the workforce. Training, equipment and supply will be wet season and dry season paddy. On average, the paddy area per provided to local medical staff. household is 1.2 to 1.3 ha upstream of upper, upper and middle Xe Bang Fai, and 2.1 ha in the lower Xe Bang Fai. It is estimated Downstream of the Nakai Dam that there is an extra 2,223 ha of dry season irrigated paddy which could be irrigated if current pumps and irrigation systems are The riparian study that will take place in 2004 will help develop repaired and improved. the Project strategy in terms of compensation and management in About half of the households along the Xe Bang Fai grow vegeta- the section of the river from the Nakai Dam to the Theun Hinboun bles in riverbank plots during the dry season, with an average size headpond. of 1,600 m2 per household (RAP, 2003). Xe Bang Fai 165 EAMP Main Text Livestock & Animal Husbandry In Xe Bang Fai and Nam Kathang communities, nearly 40% of the On average a household raises two to three head of cale, one pig population obtains domestic water supply directly from the river and ten chickens (RAP, 2003). Buffalo is the main source of dra (GOL, 2001). On average, only about 20% of the population has power for land preparation, although power tillers are becoming some type of sanitary facility. more common, particularly in the larger and more prosperous Highway No.13 is paved and has recently been upgraded for most roadside villages. Cale are a form of savings, and when needed of the route. Highway No.12 and the section of Road 8b below the they are sold for cash to meet household expenditure require- escarpment (i.e., Thakhek through Gnommalat to the proposed ments. Power Station site) are gravel (lateritic) surface roads of acceptable quality. Most of the bridges along this route have been replaced Fisheries & Aquaculture and are now of good quality. Access tracks into the villages of the Villagers fish intensively at the subsistence level. The only com- middle Xe Bang Fai are of poorer quality. mercially active fishing village is Ban Na Kio, located on the con- Education fluence of the Nam Phit and the Xe Bang Fai. The percentage of fish caught that is sold in local markets varies along the different Although the education status is slightly beer than on the Nakai sections of the Xe Bang Fai and among households (over 50% in the Plateau, many schools do not always function properly, due to Upper Xe Bang Fai). Fish is an important part of the diet and the the lack of equipment and the oen insufficient qualifications and main source of protein. experience of teachers. Rivers are viewed as a community resource which belongs to Approximately 32% of adults are reported to be illiterate, but in all everyone, and so there are no explicit "property or exploitation probability there are more who are functionally illiterate, having rights". People use a variety of techniques, and exploit all species aended only a few years of school and not practiced reading and (not only fish, but also larvae, snakes, frogs, invertebrates) where writing. Only 12% have aended secondary school, and about 6% possible, including in the Xe Bang Fai and its tributaries, in paddy have progressed beyond secondary school (RAP, 2003). Education fields and in other small bodies of water. level on the lower Xe Bang Fai is significantly higher than in the rest of the lowland areas. On average, households catch several kilogrammes of non-fish aquatic products monthly. The most productive months corre- Public Health spond with the rainy season, from April to October. This is specifi- Apart from malaria, which is suspected to have a higher occur- cally significant for the tributaries of the Xe Bang Fai. The types of rence rate here, dengue haemorrhagic fever and schistosomiasis, equipment most commonly used during the dry season are scoop which have not yet been reported in the area, the Project Area is nets, 3 cm gillnets, long-line hooks and hand spears. During the fairly representative of public health problems occurring in the wet season, single hooks, li nets, long-line hooks, bamboo traps country as a whole. Access to medical facilities, use of mosquito and catfish hooks are most commonly used. nets and nutritional status is in most respects beer in the lowland Aquaculture is not well developed in the lowland communities. areas than on the Nakai Plateau. One reason might be the relative abundance of indigenous fish within the river itself. The lack of infrastructure and a well-devel- Infectious Diseases oped market system or transport services are other explanations, In 2001 about 7% of the surveyed population was reported to be as well as a lack of appropriate techniques. There is a signifi- suffering from an illness, with acute malaria the most frequently cant opportunity to develop and expand aquaculture within the reported. Other signs of illness included coughing, skin eruption Issues region. and difficult breathing. The two groups with the highest suspi- cion of malaria were the age extremes: children under five (18%) Income and adults over 60 (12%). However, blood analysis for the malaria parasite revealed very few positive cases. Approximately 97% of Social In 2001, household incomes were highest in upper Xe Bang Fai, and lowest in the Middle Xe Bang Fai (GOL, 2001). The average the population use bed nets to prevent malarial infection through income per year of 6.1 million Kip in all downstream communi- mosquito bites (compared to the rural Laos average of 78%) (RAP, ties is more than three times that reported for the Nakai Plateau in 2003). 1998 (1.9 million Kip). However, because of the devaluation of the Reproductive Health Kip between 1998 and 2001, the US$ averages show less difference: US$ 664 in the lowlands compared to US$ 450 on the Plateau. The fertility rate among the sampled population in the low- land communities was 5.6 children born per woman, (against a Off-farm sources account for a considerable amount of income for national average of 4.9). The crude birth rate is 32.4 per 1,000 (34.0 many lowland communities. Income from shops varied from 1.8% at national level) (GOL, 2001). The maternal mortality ratio was to 5.6% on average per household in the lowland areas and 1.4 to found to be 133 deaths per 100,000 live births, significantly lower 8.2% for income from services. Wages in private and public sectors than the national average of 530 per 100,000. and pensions accounted for 28%. This reveals that the economy appears to be more diversified in relation to sources of income. Nutritional Status Nakai Plateau households derived far less income from wages (8% Overall, the health profile appears to be poorer than that of other to 11%, 1996-98). rural communities. The basis for this is a generally worse nutri- Infrastructure tional profile. Though people supplement their protein intake with fish, other sources seem to be inadequate. Other components of the The recently built transmission line from Thakhek to Nakai also diet (leafy green vegetables, protein and iron-rich food and eggs) distributes electricity to the Mahaxai area. Recent rural electrifica- are consumed more rarely. tion projects, in particular the Southern Provinces Rural Electrifi- The problem is critical for children under 5, who when compared cation Project, have been expanding the distribution grid to the Xe to the national level, are more wasted (20% versus 14%), stunted Bang Fai region. In the lower Xe Bang Fai most of the villages are (62% versus 44%) and underweight (66% versus 42%). The situa- now connected to this distribution grid. tion is beer for adults, who are slightly less malnourished (2%) 166 Xe Bang Fai EAMP Main Text and underweight (3%) than the national average (respectively 3% tion and compensation programme consists of the following com- and 4%). ponents: Impacts · Partial clearance of biomass in the reservoir, to mitigate against adverse impacts from water quality; Changes in the flow of the Xe Bang Fai will have direct impacts · Design and construction of a large regulating pond to mitigate in terms of hydraulics and water quality, which in turn will have against fluctuations in discharge (from the Power Station) and various secondary impacts in terms of aquatic biodiversity, erosion thus in levels of the Xe Bang Fai; and livelihoods. · Construction of the Downstream Channel instead of using the Domestic Water Supply Nam Kathang, mitigating against erosion that would occur in the smaller Nam Kathang, which would affect both people liv- A proportion of communities residing along the Xe Bang Fai ing near the Nam Kathang, and Xe Bang Fai water quality and obtains domestic water supply directly from the river. Therefore fisheries; any negative changes in water quality highlighted in the analysis · Installation of an aeration weir in the downstream channel, in Chapter 3 could impact the domestic water supply of these com- and aeration structures in the Nam Kathang release, to miti- munities with possible health implications. gate against low oxygen water; · River bank protection at Nam Phit (downstream channel) and Fisheries Xe Bang Fai junction to mitigate against erosion; The main impact for livelihoods is expected to be on fish resource, · Compensation for any loss or damage to permanent structures due to the changes in water quality, hydraulics and morphology where it is not economical to implement bank protection and of the river. However, uncertainties in these changes and lack of stabilisation; and knowledge on the Xe Bang Fai fish biology make the assessment · Agreement in the PPA to shut down the power plant during of the fish losses very difficult, for both the Xe Bang Fai and its over bank flooding, to mitigate against flooding in the wet sea- tributaries. son. Lossestimatesforthepotentiallyaffectedareacouldbeintheorder To determine the impact on livelihoods, health and the fisheries of 400 to 500 tonnes/year for the first year, corresponding to a 33% of the Xe Bang Fai communities, several consultation and socio- to 37% loss (RAP, 2003). This would represent a cash income loss economic surveys will be carried out prior to and during Project ranging from 0.5% (Nam Kathang/Nam Gnom areas) up to 4.6% operations. (upper Xe Bang Fai). In terms of imputed income, the decrease Details of the costs and schedules for all these activities are pre- would be around 5% on the whole downstream area (RAP, 2003). sented in the Xe Bang Fai Strategy in the RAP, which is designed to mitigate and compensate against adverse impacts. Erosion Domestic Water Supply Changes in the hydrology of the Xe Bang Fai will result in an increase of the rate of erosion whilst the Xe Bang Fai readjusts its In addition, rather than speculating on the quality of waters in the morphology. The process of adjustment to the river morphology is Xe Bang Fai during the early years, and its suitability for domestic likely to be slow and obvious, which will give communities time to use, the Project is prepared to support the development of other adjust without unpredicted losses to property or injury. However, sourcesofdomesticwater.Inthosevillageswhereitisassessedthat Social there is the potential for some permanent structure to be lost or some or all of the villages depend partly or fully on the Xe Bang damaged as a result of this erosion. Fai for household water use, then alternative sources of domestic water may have to be provided. Riverbank Gardens Issues Fisheries In the dry season, riverbank villagers frequently cultivate vegeta- bles in gardens on the riverbed and on banks for household con- A fisheries replacement programme will be implemented, aiming sumption, and less regularly for trade. Raising the water level by at developing systems for raising fish, which could replace the loss up to 4 m will involve the likely loss of many of these arable areas. in the Xe Bang Fai due to the Project. Alternative or replacement On the other hand, the greater reliability of irrigation water and fish production systems could include fish ponds and rice fields the reduced costs for pumping will contribute to the maximization (modified to provide fish refuges). The exact method developed of irrigation potential in these areas. will vary depending on: i) topography and geography, ii) the surrounding farming systems; iii) the availability of land; iv) the Access requirements of the villages and markets; v) the cost of operation/ The increase in water level will also render current modes of cross- maintenance; and vi) a range of other factors. ing the Xe Bang Fai in the dry season no longer possible. These cur- Erosion rent modes include temporary bamboo bridges or walking across For impacts on community infrastructure resulting from increased rapids. erosion, both remedial mitigation measures, such as bank protec- Construction Workers tion, and asset and livelihood compensation will be considered. NTPC will implement the most appropriate measure or combina- The potential impacts from the influx of construction workers and tionofmeasuresonacase-by-casebasis.Wherefeasible,theProject construction traffic will be similar to those identified for the Nakai will assist in the relocation of buildings. Prior to COD a survey of Plateau. assets along the river bank will be undertaken and mitigation and/ Mitigation, Management & Monitoring or compensation will be planned. Following COD regular trips will be conducted by the Project to detect abnormal erosion and Xe Bang Fai Strategy impacts on previously identified village infrastructure and liveli- hoods. Villagers will also be able to alert the District Compensation The objective of mitigation prior to Project Operation is to limit Commiees of any abnormal erosion rates and affected infrastruc- impacts related to water quality and erosion. The planned mitiga- ture and livelihoods. Xe Bang Fai 167 EAMP Main Text Riverbank Gardens significant impacts are expected on access across the river, river- Incaseswhereriverbankgardensareunabletoberelocatedfurther banks gardens or flooding for the communities that reside there. up in response to increased water levels, then NTPC will assist in Although modelling has indicated that water quality, in terms of re-establishing gardening activities as requested by communities. dissolved oxygen, will be adequate in the Nam Kathang, any water NTPC will quantify the impact on riverbank gardens by means of: of poor quality released from the power station may impact com- i) baseline socio-economic surveys; ii) a study of river gardens in munities utilising surface water for domestic use. Adverse water each village, in terms of "gardening system", tenure, and income quality conditions coupled with impacts on the Xe Bang Fai may or food productivity two years prior to COD; and iii) consultation negatively affect the fisheries of the Nam Kathang. with villages. Following COD, and if required by a particular vil- lage, a study will be undertaken to assess the actual effect on riv- Mitigation erside gardens. An aeration structure has been included in the design of the Nam Access Kathang release from the regulating dam to help improve water quality for the communities downstream. The Project commit- Since temporary modes of crossing the Xe Bang Fai in the dry sea- ments to providing the Nam Kathang communities with domestic son will no longer be possible, the impact on such access needs water of adequate quality are the same as outlined for the Xe Bang to be determined. A study will investigate objectives, means and Fai above. A survey will identify those communities currently infrastructure used to cross and prediction of the impacts will be using surface water as their main source of domestic water and made. NTPC has commied to the purchase of additional boats to then may provide an alternative source of domestic water as nec- the concerned villages. essary. Regional Health Programme Impacted households will be monitored using similar question- naire base surveys as those that will be used for the Xe Bang Fai. The Project's Regional Health Programme is designed to directly These surveys on the Nam Kathang will focus on the fisheries mitigate against any adverse health effects due to increased con- catch, with a negative change triggering the implementation of struction population and to raise the health standards of the local compensation activities to restore cash and/or imputed income population. The objective is to combine the Project's health care from any losses in fish catch. activities with the GOL provincial and countrywide programmes. To achieve this it will be necessary to: i) inform communities on The Nam Kathang communities will benefit from the Projects endemic diseases, control programmes and correct health care Regional Health Programme presented in the Xe Bang Fai section measures; ii) ensure a sufficiency in essential drugs; iii) train and earlier. transfer appropriate technology among health workers; and iv) provide support to disease control programmes. Project Lands Nam Kathang Baseline The baseline data, in terms of land/assets and livelihoods, is cur- Baseline rently being acquired as part of the compensatory and manage- Along the Nam Kathang a total of 1,161 households are present in ment process. 17 villages (GOL, 2001). Communities mainly consist of Lao Loum, Impacts Issues including eight Lao Kaleung, two Phu Thai and one Tai Bo domi- nated village. The Makong ethnic group is predominant in five of In total 11,536 ha of land could potentially be impacted to some the villages. The district centre of Ban Gnommalat Tai has a very degree by the construction of the Project. Lands will be leased by diverse composition of groups. GOLto NTPC and will be of sufficient size to enable NTPC to carry Social The Nam Kathang area, with its dependency on paddy cultivation out construction and operation of the Project. Project construction and fishing, is typical of many lowland areas in Lao PDR. How- activities will require the acquisition or use of land, and this will ever, the communities are less reliant on fish than communities require compensation to the current owners for the loss of land, of the Xe Bang Fai. In addition to the importance of rice and fish- loss of livelihoods generated from that land, or for loss (or reloca- ing, dry-season riverside gardens supply most of the vegetables tion) of assets on that land. The acquisition of Project Lands for for local consumption, with over 50% of households using an area constructionwillresultinarangeofimpactsincludingdisturbance of riverside garden. and temporary or permanent land acquisition, all of which will Issues concerning development of the agriculture sector are ineffi- require compensation to project affected persons (PAP). Two main ciencies in land and water use, amount of fallow land and frequent categories of Project Lands are defined: i) Category 1 ­ exclusive crop loss due to flooding or drought conditions, compounded with occupancy rights; and ii) Category 2 ­ co-existent but dominant the continued use of marginal land and the shiing cultivation sys- occupancy rights. tem common to this region. Mitigation & Management Lowland communities have started targeting other sectors of employment including commercial development of livestock and A "Baseline Study" will be conducted to identify and catalogue forest products. all land and assets, including man-made improvements, that will be affected by construction, excluding the reservoir area. A list of Education and health issues are similar in type and extent to those fiy-seven Project Lands, as defined in the ConcessionAgreement, highlighted for the Xe Bang Fai communities. and the areas required for construction within these Project Lands Impacts are identified in the RAP. Areas to be surveyed will be for the con- struction of the Nakai Dam, the saddle dams, the Power Station, The Project will release from the regulating dam a discharge the Headrace Channel, the Power Conduit Intake Structure, the equivalent to its natural flow into the Nam Kathang. The hydrol- SubStation, the Regulating Pond, the Regulating Dam, Residence ogy of the Nam Kathang will remain unaltered and therefore no Nam Theun, quarry areas, work camp areas, as well as the cor- 168 Nam Kathang EAMP Main Text ridors for the 500 kV and 115 kV Transmission Lines, and for all will be responsible for monitoring of the infrastructure construc- roads to be upgraded and constructed. tion and activities, and will report quarterly to the RMU and the The objectives of the Baseline Study are: Reselement Commiee. By comparing progress on the ground 1. Toproducemapsandadatabaseofland,assetsandlivelihoods with the implementation schedules, the RMU can identify areas directly affected by the construction on Project Lands, and an of weak implementation and take remedial action. For those prob- assessment of the extent of both direct and indirect impact on lems requiring decisions from higher authorities, the RMU will these; report to the Reselement Commiee. 2. To produce a registry of all assets and land areas within Project External Monitoring Lands, outside the Nakai reservoir; and 3. To make: i) an estimation of current value and/or productivity Independent external monitoring will be carried out by a third of these assets, land areas and livelihoods within the Project party, focusing on changes in social and economic conditions of Lands; ii) an estimation of degree of impact on villagers'assets, individual households. Based on existing socio-economic charac- land and livelihoods in relation to total villager assets and live- teristics of the villages and the type of rehabilitation and reloca- lihoods; and iii) a compensation recommendation. tion schemes to be implemented, a set of indicators will be devel- The Baseline Study will be in two phases. Phase 1 will consist of oped for affected households and villages, including income level, mapping and database development based on satellite interpre- sources of income, food sufficiency, basic health and education tation and Phase 2 will consist of a field survey to confirm land/ conditions, women's status, etc. The monitoring and evaluation assets location, dimensions and ownership. will last for the duration of the period of implementation of the Initially, high resolution satellite imagery will be acquired and RAP, which is likely to be over a period of nine years. onscreen digitization carried out to identify and catalogue the The Social and Environmental Panel of Experts will also support various types of land and assets. Phase 1 for all Project Lands from this external monitoring. Ban Oudomsouk to the Downstream Channel confluence with the Xe Bang Fai has already been completed, representing 32 of the Grievance Procedure 57 Project Lands. Starting in the dry season of 2004, prior to the Even among well-planned reselement and compensatory pro- commencement of the Preliminary Construction Works, a ground grammes, individual or village complaints are bound to arise. To study will be undertaken to identify and catalogue all man made ensure that the basic rights of PAPs are protected, concerns ade- improvements on Project Lands. quately addressed and entitlements delivered, a grievance proce- Following the ground study, NTPC and GOL, in consultation dure will be implemented. with the PAPs will develop a compensation scheme applicable to A Project Grievance Commiee will be established and will be the impacts and conditions for each Project Land. A value will be headed by a senior provincial official. Other members of the Com- placed on the assets or land affected, following guidelines given miee will come from the Justice Department, the Lao Women's in the Asset/Land Compensation Agreement. Estimation of asset/ Union (LWU), the Ethnic Council and one member will be from the land value may be based on local market replacement value or Reselement Commiee. The Commiee will have the capacity to importance of that asset/land to PAP livelihood. An agreed sched- deal with complaints and grievances brought to it by claimants. ule of base asset value will be determined aer consultation with NTPC, RMU and the district government. The agreement will also If an affected person is not satisfied with the compensation pack- Social specify the type of compensation applicable to each PAP, whether age or if, for any reason, the compensation does not materialise in cash, in kind, as rehabilitation or some other form. according to the agreed schedule, he or she has the right to make a claim. There are three steps to resolve grievances, from the local Further details on the interpretation of imagery, list of asset types, level District Reselement Working Group (step one) to the Reset- Issues indicative compensatory scheme and values allocation are pre- tlement Management Unit (step two) up to the Grievance Com- sented in the RAP. miee (step three). Beyond the Grievance Commiee, access to the courts is a last resort. Details of this procedure are given in the Monitoring RAP (2003). TohelpensurethattheRAPisimplementedsuccessfullyandliveli- hoods have improved aer reselement, a monitoring programme Enhancement of Capacity will be implemented. This monitoring will also ensure that activi- Given that the RMU and District Reselement Working Groups ties for the Xe Bang Fai and Project Lands are implemented suc- have been recently established in Lao PDR, and that the institu- cessfully. The programme will consist of two components: i) inter- tional capacity in local government, including provincial, district nal monitoring; and ii) independent external monitoring. and village bodies needs further development, a training pro- Internal Monitoring gramme will support the implementation of the RAP. The RAP is designed to build the institutional capacity required to assist deliv- Internal monitoring will focus on the physical progress of resele- ery of benefits from the creation and operation of the Nakai Reser- ment implementation and activities for the Xe Bang Fai and Project voir. Provision for institutional strengthening is discussed in detail Lands against the schedule in the RAP. The Reselement Office in the Concession Agreement and the RAP (2005). Monitoring 169 EAMP Main Text Issues Social 170 Monitoring EAMP Main Text 5. Public Consultation & Disclosure World Bank & World Commission on Dams Policies 172 The Stakeholders 172 Public Consultation & Disclosure Process 172 Three Phase Process 172 Methodology 173 Consultation & Participation Activities 175 Media Relations 175 Summary of PCD Activities July 2002 - March 2005 175 The PCD Process Since the Advanced Draft of the EAMP to Apprasial 177 Main Stages of Information Dissemination, Consultation & Disclosure 177 Main Stakeholders in Future Consultation & Disclosure 177 Information Dissemination to the General Public 177 Local Consultation Events 178 Public Disclosure 180 Stakeholder Input into Project Design 180 Issues Raised by Independent Reviewers & Project Responses 180 Influence of Consultations on Project Planning 180 Influence of Consultations on Resettlement Issues 182 Influence of Consultations of the PCD Process 182 Institutional Arrangements for PCD Process 182 Public P ublic consultation and disclosure (PCD) plays a key role Consultation in enabling the public to participate in the planning of the Project. The PCD process has been carried out based on the following primary objectives: · Ensuring that stakeholders' concerns, experiences and recom- mendations, especially from affected persons, are integrated in the design, planning and implementation of the Project; · Increasing public awareness and understanding of the Project; especially on mitigation measures to reduce impacts and improve the livelihood of the affected people; and · Enhancing development initiatives through the support and direct involvement of affected people and communities. World Bank & World Commission on Dams Policies 171 EAMP Main Text EAMP Main Text Table 5.1: Project stakeholders Local Regional National International Households and villages on the Nakai Plateau Community leaders GOL ministries Power utilities Downstream communities District agencies The people of Lao PDR Thai Government Project Land communities Provincial agencies National NGOs Embassies Communities in the NNT NBCA and proposed corridor areas. Businesses and contractors National media International Financial Institutions NTPC investors and Financial Institutions International NGOs International media Hydroelectric dam developers As of the beginning of 2004, there have been more than 250 public · An independent dispute resolution mechanism should be consultation and participation briefings and meetings, which have agreed with the other stakeholders at the beginning of any taken place at the local, regional, national and international levels. process. Dialogue has been established with interested groups and stake- holders who are directly or indirectly involved in the Project and The Stakeholders who have expressed a wish to participate in the Project's public consultation program. The five main stakeholder groups comprise of: i) people directly The main focus of the following chapter is on the outputs of these affected by the Project; ii) government officials at the district, pro- briefings and meetings, and how feed-back was incorporated into vincial and national levels; iii) the broader interested national the Project design. The chapter begins by identifying the PCD community; iv) NGOs operating in Lao PDR; and v) international policies of the World Bank and World Commission on Dams. This NGOs, international organisations and other interest groups, is followed by the identification of the Project stakeholders and including the local, regional and international media. 5 an outline of the approach taken. The following sections discuss The various individuals, communities, government and non-gov- activities to date and details the main comments received from ernment agencies and organisations are further defined in Table these discussions and their incorporation into the Project design. 5.1. with their interests and requirements in terms of information Finally, the chapter clearly spells out the plans for consultation and dissemination presented in Table 5.2. disclosure leading up to Wold Bank appraisal, as well as during implementation of the Project. Public Consultation & Disclosure Process World Bank & World Commission on Dams Three Phase Process Policies Consultation at the local, regional, national and international lev- The three World Bank safeguard policies of Environment Assess- els has started and will continue to progress through a three-phase ment (OP 4.01), Involuntary Reselement (OP 4.12) and Indig- process: enous People (OD 4.20) require the involvement and participa- Phase 1: Information Collection & Dissemination Consultation tion of all stakeholders, including affected people and NGOs, in the planning and implementation of the Project. The World Bank This initial phase of consultation aimed to collect and disseminate also requires a culturally appropriate strategy that allows for the information. Data has been collected on the human and physical participation of indigenous people and uses appropriate consulta- characteristicsofthecurrentenvironmentinordertopredictProject Public tion methods which take advantage of local knowledge. Ongoing impacts. As part of this phase, information was disseminated to PCD is also required during the construction and implementation stakeholders regarding the Project features and the implications in phases of the Project. terms of changes to the social and physical environment. The PCD process has also taken into account the requirements Phase 2: Consultation with Stakeholders set out in the World Commission on Dams report, summarized below: Comments continue to be sought from stakeholders in response · The participation of indigenous and tribal people in consulta- to information gathered as part of Phase 1. The information was tion is a process of communication and negotiation, spanning disseminated and discussion of the alternatives and proposed the planning and project cycles; mitigation measures were, and continue to be, encouraged. Issues · Effective participation requires an appropriate choice of com- for stakeholders that may have been previously overlooked or are munity representatives; outstanding are given a forum for review. · The consent of affected indigenous and tribal people should be Phase 3: Active Involvement in Project Design & sought prior to key points in the decision making process; · The manner of expressing consent will be guided by custom- Implementation ary laws and customs, and by national laws; Based on the discussion of Phase 2, a set of mitigation measures · At the beginning of the process the affected people will state were developed that address Project impacts. The process of stake- how they will express their consent to key decisions; holder involvement and identification will continue during Project · The integrity of community processes should be guaranteed; implementation. This process provides for cyclical feedback, · Communities shall not be divided or coerced, and shall be free should deficiencies appear at any stage either prior to or during of manipulation; and the Project implementation. 172 Public Consultation & Disclosure Process Public ConsultationEAMPDisclosure and Main Text Table 5.2: Stakeholders, their interests and involvement in the consultation and disclosure process (source: SDP, April 2004) Stakeholders Interests & Experience Consultation Process to Date Nakai Plateau villagers to be relo- Positive with regard to their resettlement and the pro- Preliminary consultation in 1995. cated or otherwise affected: posed livelihoods. Currently involved in demonstration Intensive consultation 1997-1999 in all villages. approximately 1,200 families farms and pilot village relocation. Pilot village consultation from 2001. Establishment of an Information Centre in Nakai in RMU and Nakai DRWG based in Nakai. Village Resettlement Committees organised. Villagers along the proposed down- Positive towards irrigation potential but concerned over Consultation about impacts held in 1997. stream channel: about 198 families impacts of flooding and livelihood. Further, detailed, consultations about mitigation plans and compensation options to be carried out in 2004 by NTPC and RMU. Villagers along the proposed Trans- Interest in fair and prompt compensation. Consultation about impacts held in 1997. mission Lines Further, detailed, consultation about mitigation plans to be carried out in 2004 by NTPC and RMU. Villagers with assets under other Yet to be consulted in detail about project impacts. Detailed design and impacts in the process of being determined. Project Construction Lands Planned consultation process to commence in 2004 but basic information available from RMU. Villagers along the Xe Bang Fai Positive towards irrigation potential but concerns over Consultation about impacts held in 1997. increases in flooding and impacts on livelihood. Further, detailed, consultation about mitigation plans to be carried out in 2004 and onwards by NTPC and RMU. Local Authorities Representation in decision making process and capacity Ongoing consultation and meetings since 1997, assessment of capacity, building. and inclusion in key institutions such as the RMU and DRWG. Provincial Organisations Representation in decision making process and capacity Ongoing consultation and meetings since 1997, inclusion in RC. building. National Government National legal and policy framework, project viability Ongoing consultation and meetings since 1995, inclusion in the RC, STEA (Ministries and STEA) financing and representation in decision making. part of National Level Consultation. 5 Mass Organisations Representation in decision making process and capacity Ongoing consultation and meetings since 1997, inclusion in key institutions (LWU, LNF) building. such as the RMU, DRWGs and VRCs. NGOs International standards for social and environmental Involved in some local and all national consultation meetings, reviewed aspects and project viability. documents and undertook site visits, including in 2003. Panel of Experts International standards for social and environmental POE has carried out site visits and consultation since 1996 and has aspects and project viability. reviewed all relevant documents. Donors and Financial Institutions International standards for social and environmental Involved in all national consultation meetings, reviewed documents and site aspects and project viability. visits from 1995. Public Embassies International standards for social and environmental Involved in all national consultation meetings, reviewed documents and site aspects and project viability. visits from 1995. Thai stakeholders (EGAT, private International standards for social and environmental Involved in negotiations of the PPA, all national consultation meetings, sector, Govt) aspects and financing. reviewed documents and site visits. Consultation Methodology group meetings, models, Participatory Rural Appraisal tech- Appropriate interactions and information sharing techniques have niques and site visits; · Translation of Project documents and summaries into Lao lan- been developed for these different stakeholders in order to ensure guage. These are used in particular for local leaders, regional a good mutual understanding. officials and national stakeholders; The Approach · Use of local NTPC Project Information Centres (PIC) at Vien- tiane,Thakhek,andNakai. Theseprovidewrienmaterialand Throughout the PCD process it has been important to take into information on the Project, deal with inquiries and requests for account the following: additional information, and conduct periodic meetings with · Local power and authority structures and the need to ensure village and district representatives; and that participation in consultation activities is not dominated by · Direct contact with stakeholders through electronic or wrien local authorities; media, group and individual briefings, radio and television · Participation of women and vulnerable groups; and interviews, distribution of detailed Project information, organ- · The documentation of the process. isation of symposium and forums, and site visits for interna- tional stakeholders. Use of Suitable Techniques Table 5.3 outlines the tools used to disseminate information to spe- Techniques were developed to meet the requirements of the cific groups of stakeholders. diverse and numerous participants involved. The techniques Language Issues adopted include: Information gathered on language usage has established that the · Use of visual representations including pictures, diagrams and vast majority of people from ethnic groups in the Project area can posters, especially at the local and regional level; speak Lao, and the different ethnic languages are for the most part · Face-to-face communication where levels of literacy are recog- confined to domestic use. Only a small percentage of the affected nized as being low. This includes use of seminars, workshops, populationdonothaveagoodworkingknowledgeofLao.Inaddi- general village meetings, semi-structured interviews, small tion, none of the ethnic languages have any wrien form. Thus, it Public Consultation & Disclosure Process 173 EAMP Main Text EAMP Main Text Table 5.3: Consultative mechanism used with key stakeholders Stakeholders/Project Area Key Information Timing Mechanisms & Approaches Nakai Plateau villagers to be Relocation plans, site selection, Formal consultations in 1997- RRA and PRA techniques. relocated: 5,684 persons village layout, livelihood scenarios, 2000. Information dissemination, meetings and discussions compensation, training. Regular consultations from 2001 (village, group and individual levels) to create feedback as required. loop ­ posters, booklets, information centre, demonstra- tion farms and visits to sites. Villagers with assets under other Relocation plans, compensation Regular consultations from 2003. Information dissemination, meetings and discussions Project construction Lands and site selection if required. (village, group and individual levels) to create feedback loop ­ posters, booklets, information centre. Villagers with assets under the Relocation plans, site selection, Formal consultations in 1997, RRA and PRA techniques. proposed Downstream Channel village layout, livelihood scenarios, 2003 and 2005. Information dissemination, meetings and discussions compensation, training. Regular consultations from 2007 (village, group and individual levels) to create feedback as required. loop ­ posters, booklets, information centre and visits to sites. Villagers along the Xe Bang Fai Mitigation framework, project im- Formal consultations in 1997 and RRA and PRA techniques. pacts along the Xe Bangfai, com- 2003 and 2005. Information dissemination, meetings and discussions pensation, training and for directly (village, group and individual levels) to create feedback affected families, site relocation loop ­ posters, booklets, information centre and visits and support services. to sites. Villagers with assets under the Mitigation for project impacts, com- Formal consultations in 1997 and RRA and PRA techniques. proposed Transmission Line pensation and support services. 2005. Information dissemination, meetings and discussions Corridor (village, group and individual levels) to create feedback loop ­ posters, booklets, information centre and visits to sites. Local GOL Organisations Project features, impacts and miti- Meetings, discussions and seminars Training and capacity building seminars and workshops gation, resettlement, compensation from 1995 onwards. from 1997 in consultation techniques and participation 5 and implementation schedule and Local, Regional and National level as members of PCPP Teams. budget as well as WB Safeguard consultations from 1996. Assistance in setting up local consultation bodies and Policies. monitoring procedures. Provincial Organisations Project features, impacts and miti- Meetings, discussions and seminars Training and capacity building seminars and workshops gation, resettlement, compensation from 1995 onwards. from 1997 in consultation techniques. and implementation schedule and Local, Regional and National level Assistance in setting up local consultation bodies and budget as well as WB Safeguard consultations from 1996. monitoring procedures as part of the Resettlement Com- Policies. mittee. Translation of key project documents into Lao for distribu- tion. Mass Organisations (LWU, LNF ) Project features, impacts and miti- Meetings, discussions and seminars Training and capacity building seminars and workshops gation, resettlement, compensation from 1995 onwards. Local, Region- from 1997 in consultation techniques and participation and implementation schedule and al and National level consultations as members of PCPP Teams. budget as well as WB Safeguard from 1996. Assistance in setting up local consultation bodies and Policies. Consultation monitoring procedures as part of RMU and other bodies. Translation of key project documents into Lao for distribu- tion. Public GOL (Ministries and STEA) Project features, impacts and Meetings, discussions and seminars Training and capacity building seminars and workshops mitigation, resettlement, compensa- from 1995 onwards. Regional and from 1997 in consultation techniques and participation tion, implementation schedule and National level consultations from as members of PCPP Teams. budget. WB Safeguard Policies. 1996. Assistance in setting up local consultation bodies and monitoring procedures. Translation of key project documents into Lao for distribu- tion. Local NGOs Project features, impacts and miti- Local, Regional and National level Participation in Local, Regional and National level work- gation, resettlement, compensation consultations and briefings since shops and meetings and site visits. and implementation schedule and 1996. Program linkages between RMU and local NGO activi- budget as well as WB Safeguard ties. Policies. Translation of key project documents into Lao for distribu- tion. International NGOs Project features, impacts and miti- National level consultations and Participation in National level workshops, meetings and gation, resettlement, compensation briefings since 1997. site visits. and implementation schedule and Translation of key project documents into English for budget as well as WB Safeguard distribution and websites. Policies. Thai Stakeholders Project features, impacts and miti- National level consultations and Participation in Local, Regional and National level work- gation, resettlement, compensation briefings since 1997. shops, meetings and site visits. and implementation schedule and Translation of key project documents into English for budget as well as WB Safeguard distribution and websites. Policies. 174 Public Consultation & Disclosure Process Public ConsultationEAMPDisclosure and Main Text Table 5.4: Media relations since August 2000 No. Organisation Location Date/Event 1. France2 TV Paris 3 August 2000/55 min feature broadcasted on the programme "Geopolis". 2. France2 TV Paris 3 June 2001/15 min feature broadcast on the programme "Faut Pas Rever". 3. International Herald Tribune New York Visited the Project site in early March 2002 and released a story on 11 March 2002. 4. The Nation (Thai newspaper) Bangkok Symposium "Nam Theun 2 ­ Window to the Future" July 3rd, 2002. 5. Reuters/Voice of America (VOA)/Radio France Bangkok Symposium "Nam Theun 2 ­ Window to the Future" July 3rd, 2002. Internationale (RFI) 6. Agence France Presse Hanoi Site Visit from 26 to 28 November 2002. 7. Associated Press Bangkok Site Visit from 26 to 28 November 2002. 8. Bangkok Post Bangkok Site Visit from 26 to 28 November 2002. 9. BBC Radio Bangkok Site Visit from 26 to 28 November 2002. 10. Business Day Bangkok Site Visit from 26 to 28 November 2002. 11. The Nation Bangkok Site Visit from 26 to 28 November 2002. 12. Reuters/VOA/RFI/The Nation Bangkok Site Visit from 26 to 28 November 2002. 13. Radio Free Asia (RFA) Washington Site Visit from 26 to 28 November 2002. 14. Lao Foreign Language Press Vientiane Site Visit from 26 to 28 November 2002. 15. Le Renovateur Vientiane Site Visit from 26 to 28 November 2002. 16. Vientiane Times Vientiane Site Visit from 26 to 28 November 2002. 17. RFI Paris Radio Interview by phone on 13 December 2002. 18. BBC TV London/Bangkok BBC TV crew visited Laos and the Project site on 13-14 February 2003. TV reports were broadcast on 19 and 23 February 2003 on BBC World News, Reporters and BBC domestic news programmes. 19. Lao TV Vientiane TV report and video on the Project's Resettlement and Envi-ronmental plans produced in April 2003. 5 20. Asahi Shimbun (Japanese Daily Paper) Tokyo/New Delhi Visited Project Site on 13-14 June 2003. 21. The Economist Bangkok Released a story on Laos and the Project on 18 September 2003, visited the Project site on 25- 26 September 2003 and published an article on Mekong Development 30 December 2003 22. NHK TV (Japan) Bangkok NHK TV crew visited Laos and the Project site on 25-26 September 2003. 23. Radio Australia Canberra Phone Interview on 30 October 2003. 24. Vientiane Times Vientiane Site Visit from 9 to 11 June 2004. 25. UPI, National Press Club Washington Site Visit from 9 to 11 June 2004. 26. The Nation Bangkok Site Visit from 9 to 11 June 2004. Public 27. South China Morning Post, BBC Bangkok Site Visit from 9 to 11 June 2004. 28. Bloomberg Bangkok Site Visit from 9 to 11 June 2004. 29. Compas Jakarta Site Visit from 26 to 27 June 2004. Consultation 30. Wall Street Journal Bangkok Site Visit from 29 July to 3 August 2004. 31. All Thai press, Le Monde, Liberation, AFP, Reuters Worldwide Site Visit from 31 August to 27 September 2004. is impossible to design wrien materials in each ethnic language Consultation & Participation Activities for the purpose of consultation. Translation of oral presentations into ethnic languages ­ Brou and NumerousPCPPevents have been conductedat the local, regional, Vietic languages ­ has always been an option, and during consul- national and international levels. A summary of activities up to tation, such translations are provided whenever necessary by local October 2004 is presented in Annex N. village leaders or ethnic staff of the District Working Groups. Lan- Media Relations guage checks are made before discussions, especially for women and the elderly, who might have less exposure to the national lan- To promote widespread Project awareness, NTPC has encouraged guage. the involvement of various media and other groups in the PCD Process (Table 5.4). Gender Issues Summary of PCD Activities from July 2002 - March Participation of women in consultation requires special aention, because most women are either less educated than men, or have 2005 less exposure to the outside world and politics. In the consulta- To gain public support for the Project implementation, GOL tions, efforts have been made to include women and to encourage and NTPC have been targeting three types of audience: their participation by having separate women's groups. This has i) diplomats/donor community; ii) NGOs/civil society groups/ been possible through the central role of the Lao Women's Union academics; and iii) the media. Communications efforts were con- (LWU) at the local level consultations. ducted through the following actions: Consultation & Participation Activities 175 EAMP Main Text EAMP Main Text Table 5.5: Schedule for consultation and disclosure of the EAMP. TIMELINE DESCRIPTION `03 `04 `05 COMPLETION OF ADVANCED DRAFT Issue AD to the IFIs and the general public World Bank & ADB Appraisal of AD COMPLETION OF FINAL DRAFT ­ PHASE 2 1. Local Production of consultation material Public consultation with local people 2. National Reading period of documents Public meetings 3. Regional Public disclosure through Project website Reading period of documents Public meetings 4. International Public disclosure through Project website Reading period of the document Public meetings REVISION & DISCLOSURE OF DOCUMENTS Production of FINAL DRAFT Issue of FINAL DRAFT 5 World Bank & ADB Appraisal of FD WB & ADB Appraisal of FD DISCLOSURE AFTER APPRAISAL ­ PHASE 3 Disclosure of Documents Public disclosure on WB info shop Receive comments Review & Clearance Translation of the FINAL DRAFT EAMP GOL review and clearance WB review and clearance POE review and clearance WB & ADB Board FINALISATION FOR IMPLEMENTATION Consultation Symposium "Nam Theun 2 ­ Window to the Future" major international press agencies, the Thai press and Radio Free Public This event, held on 3 July 2002, was chaired by GOL and gath- Asia. This visit resulted in the production of a long series of media ered more than 150 participants, including Ministers, Ambas- reports on the Project all through 2003. sadors, representatives from the international donor community A series of three site visits for NGOs was conducted between Feb- and NGOs, members from the World Bank's IAG and GOL's POE, ruary and March 2003, to enable the groups to assess the actual international and local media, as well as representatives from the environmental and social situation and challenges. Around 80 provinces and villages directly concerned by the Project. The Sym- NGOs were invited by GOL, though only 20 replied and 15 actu- posium emphasized GOL's determination to implement the Project ally participated in the visits. The three-day visits provided time following international standards, in particular with regard to for discussions between NGOs and the local populations. On each social and environmental issues. The Symposium's debates thus visit, NTPC staff were available to answer any questions, while focused on three main issues: i) the national development frame- noting the concerns and advice of each NGO. In addition, debrief- work and Nam Theun 2's strategic importance, ii) social and envi- ings were organised in Vientiane on the fourth day, to allow inter- ronmental safeguard issues, and iii) the protection of Lao PDR's action between NGO staff and senior government officials in a dif- interests. ferent context. Site Visits Follow-up Actions Two site visits for Ambassadors and international organisations Working meetings and discussions have been held on different representatives in Vientiane were organised in late 2002 by GOL occasions between NTPC, GOL, diplomats and some NGOs, as and led by H.E. Mr. Soulivong Dalavong, former Minister of well as with donor community representatives in Vientiane, Bang- Industry & Handicras. kok, Paris and Washington. Interviews were given to journalists A visit for international and Lao local media was conducted in (press, radio, TV) and additional site visits were conducted with November 2002 with 15 journalists and photographers, including specific groups representing the various audiences. 176 Consultation & Participation Activities Public ConsultationEAMPDisclosure and Main Text Table 5.6: Summary of disclosure plan for the EAMP Phase Stakeholder Language Prior to WB/ADB appraisal Disclosure by Appraisal Final Version for implementation Full Partial Full Partial Full Partial Project affected persons English Lao · · · GOL stakeholders English Lao · · · GOL implementors English · · · Lao · · · National public, NGOs and English · · · mass organisations Lao International stakeholders English · · · (donors, NGOs, etc) Lao The PCD Process Since the Advanced Draft Main Stakeholders in Future Consultation & of the EAMP to Apprasial Disclosure Main Stages of Information Dissemination, Table 5.6 indicates the general type of consultation and disclosure that has been and will be to be undertaken with each audience, Consultation & Disclosure ranging from information and outreach programs with local PAPs, AnindicativeschedulefortheprocessoffinalizingtheEAMPsince to the provision of full English and full or summary Lao transla- the production of the Advanced Dra EAMP is presented in Table tions of all relevant documents. 5.5, and described in summary as follows: Information dissemina- tion and consultation before appraisal has been and will be car- Information Dissemination to the General Public 5 ried out at the local, national, regional and international levels. At Past activities were aimed at developing public awareness the local level, consultation was primarily conducted by recurrent of the Project. A symposium was organised in Vientiane on interactive workshops and presentations., and the placement of July 3, 2003 by GOL, numerous site visits were conducted for posters illustrating expected project impacts. The main groups that diplomats, media and NGO communities, the Project website have been consulted are: i) plateau reselers; and ii) villagers along Public the Xe Bang Fai. The villagers with assets under Project Lands will (www.namtheun2.com) was updated, a GOL website was cre- be consulted before and during appraisal. At the national level, it ated, and various communications supports (brochures, leaflets includedconsultationwithnationalNGOsandmassorganisations, and news releases on various topics) were produced and widely GOL authorities involved with the implementation activities, and distributed. The public awareness strategy is continuing with the Consultation the general public. This was achieved primarily by workshops and following activities: presentations. For GOL organisations involved with implementa- tion (including STEA who will review and clear the documents Table 5.7: Sections of the EAMP to be translated into Lao for GOL), there was an interactive review and training process. At the regional and international level, it included consultation with Section Degree of Translation donors, international NGOs, and Thai stakeholders in the form of Main Text Full translation public meetings in Bangkok, Tokyo, Paris, Washington DC and Annexes Vientiane. The suite of safeguard documents, revised according to A References No translation the consultations above, will be made available to all project stake- B Contributors to the EAMP Full holders before appraisal by the International Financial Institutions C Project Key Technical Data No translation and 120 days before the WB board of directors begin consideration D Technical Drawings of Project Infrastructure No translation for approval (Table 5.5). At this time GOL implementers will have E Hydrological Data Full a full translation of the revised documents. Disclosure to the local F Simulated Dam Operations Full affected people will be through an information and outreach pro- G Water Quality Modelling Assumptions Full gram, and the Lao documents will be made available to them. The H Forest & Bird Species No translation remainder of the groups will be provided with a full revised ver- I Natural Habitats Accounting Full sion of these documents. Aer appraisal and board decision, any J Mammal and Bird Species No translation required revisions will be made to project planning documents, K Fish Species No translation and then these documents will be made available to the various L HCC Environmental Requirements Full stakeholders. Of particular importance are the GOL implementers M Pest Management Plan Full and the PAPs who will be given a full Lao translation and partial N Public Consultation and Disclosure Events Full Lao translations respectively. The PAPs will also have the services O POE & IAG Full of an information and outreach program. The remainder of the groups will be provided with a revised full version of the docu- P Physical Cultural Resources Full ment. Q Riparian Release Full The PCD Process 177 EAMP Main Text EAMP Main Text Information Centres Consultations & Disclosure for Nakai Plateau Resettlers Additional Information Centres will be established in defined The2004roundofconsultationsonthePlateau focusedonpresent- locations in the Project area, as well as in Vientiane, to promote ing to PAPs the range of livelihood options that they may choose to information exchange fromthe earlieststagesofprojectimplemen- adopt, and enabling the PAPs to make a choice on both: i) the mix- tation. Afirst Information Centre and Forum will be established in ture of livelihoods; and ii) the actual location of their newly reset- NTPC's Vientiane office in 2004, displaying safeguards documents tled village. Further details of the activities that were conducted on in English and summaries in Lao language, a Project small scale the Nakai Plateau in 2004 can be found in the SDP. These include model, and a video. preparation of consultation material, methods of training the facil- Three other Information Centres including discussion forums will itators, how information was disseminated and the feedback proc- be established in Thakhek, Mahaxai, and Nakai. To assist in the ess . A presentation of concerns raised by villagers and how these implementation of such information centres and forum, the LWU will influence the planning is also included in the SDP. will play a decisive organisational role. Other than the LWU, key Consultations & Disclosure for Xe Bang Fai Riparian provincial and district officials and key villagers/local organisa- Villages tions will be identified to serve as the junction between the Project and the PAPs, through information centres and forums. These per- During the period of July to September 2004, the consultations manent centres and forums will be established just aer the com- in villages along the Xe Bang Fai will focused on: i) presenting pletion of village-by-village disclosure and consultations. what the Project will deliver in terms of quality and quantity of water; ii) the expected impacts on flow; iii) the expected impact on Mass Media aquatic life; and iv) the expected impact on their livelihoods. The Permanent and regularly updated diffusion of messages will be villagers were asked to review and comment on these predicted made through the Project website (including a newsleer, the impacts. Following this, the proposed strategy of how to monitor photo description of site works progress, news releases, etc.). the impacts and then compensate the impacts was presented, and again villagers asked to comment on how this strategy could be Key messages are diffused to the media via NTPC's designated improved and finally implemented. spokespersons through press, radio or TV interviews and reports. In addition, several key media organisations have been identified These PCD activities were conducted in 2004, although because the actual impacts on the Xe Bang Fai will occur in five to six years 5 and will be regularly updated on Project progress. These are: time, future consultations to refine the strategy, compensation and · International agencies ­ AFP (Hanoi office), Reuters (Bangkok monitoring procedures will continue to be undertaken. Office); · Thai press ­ Bangkok Post, The Nation (Thai and English edi- Further details of the activities can be found in the SDP. These tions); include preparation of consultation materials, training facilitators, · Lao agencies and press ­ KPL, Vientiane Times; methods of disseminating and gathering information, and the inte- · Radio ­ Radio Free Asia, Voice of America; and gration of feedback before appraisal. Theconcernsraised by villag- · TV ­ BBC, TV5, NHK. ers during this round of consultations and the integrations of these concerns into Project planning is also discussed. A 20-minute Project video overview (including technical, social, environmental aspects) has been prepared and will be used as a PAP Consultations & Disclosure: Project Lands basic support for general presentation in the Project Information The next round of consultation with PAPs in relation to Project Centres. A 5-minute video summary and separate technical simu- land impacts will be different from the Plateau and the Xe Bang Fai lations have also been produced for the Project website. consultations. This is because: Consultation Translation i) The impacts on PAPs is known exactly, and is of one type only ­ permanent or temporary acquisitions of land and Because of the international, multi-stakeholder and somewhat assets; complex nature of the project, all documents are originally draed, ii) These impacts will be assessed and compensation given in Public reviewed and revised in English. However, while key GOL coun- a relatively short period of time ­ less than one year for per- terparts can work in English, many GOL staff and most local vil- manent loss of land/assets, and up to three years for tempo- lagers cannot. Thus, translation of all project safeguard documents rary loss of land and assets, aer which time the PAPs will no into Lao language is a crucial feature of the consultation and dis- longer be PAPs; closure process. Various versions of the EAMP have been trans- iii) In most cases relocation will not be required; and lated into Lao, the latest being the fih dra of October 2003. Due iv) The PCD activities for Project Lands activities will be under- to the technical nature of the documents, and the limited ability or taken in groups of project lands, and thus groups of PAPs. time of PAPs to read, the consultation process will translate key The schedule will be linked to the progressive requirements aspects of the documents. Table 5.7 indicates those sections of the of the construction contractors to have full rights to Category 1 final dra EAMP to be translated for the purpose of information ProjectLands,andtohaveprimaryrightofaccesstoorthrough dissemination and consultation at the local, regional and national Category 2 lands. levels. Documents that will need to be translated for the purpose FurtherdetailsoftheactivitiesthatwillbeconductedfortheProject of disclosure at appraisal include the SESIA and the EAMP (main Lands consultation in 2004 can be found in the SDP; these include text and annexes). information gathering, preparation of consultation material, meth- Local Consultation Events ods of training the facilitators, dissemination of information, land and assets registration, and the compensation process. Two additional local consultation events, for the Nakai Plateau and the Xe Bang Fai, have been carried out before appraisal and International Stakeholder Workshops one main local consultation event is proposed before appraisal Several international workshops were held in Bangkok, Tokyo, for the communities affected by construction activities in Project Paris, Washington DC and Vientiane during the period of August lands. Details are presented in the SDP. to September 2004. The goal of these international workshops was 178 The PCD Process Public ConsultationEAMPDisclosure and Main Text Table 5.8: Concerns and issues raised during the 2004 International Workshops (non exhaustive). Concerns and Issues Organisations Responses Many promises made by donors and the Thai Govern- Terra, Thailand and NTPC consultation process is more comprehensive and transparent and involves ment for the Pak Mun project in NE Thailand were Representatives of all stakeholders. In the case of Nam Theun 2, the Concession Agreement is legally not fulfilled and affected persons were not properly Concerned Groups binding for NTPC with income targets. compensated. Why the situation will be different in the for Pak Mun. GoL invited representatives of Thai villagers affected by the Pak Mun project in case of Nam Theun 2? Thailand to attend the Vientiane Workshop and to visit the site. Fisheries impacts may have not been sufficiently Terra and Independ- Comprehensive studies of the Project impacts on the fisheries have been under- studied in particular for the downstream Xe Bang Fai ent experts, Thailand taken. The Project is committed to properly compensate the affected people living area and tributaries along the affected portion of the Xe Bang Fai as well as those living in the hinter- land, and who also rely on the Xe Bang Fai for fisheries. Not enough time was given to review the documents Friends of the Earth, The documentation has been posted on NTPC website since May 2004 onwards and prior to the workshop. Japan earlier versions have been available since 2002. Further opportunities for comments will be available during the appraisal process. (NTPC) Logging on the Nakai Plateau has degraded the Mekong Watch, Logging was undertaken on the Plateau since the mid-1980s and was discontinued environment and affected the livelihoods of the people Japan in 1999. The WB has undertaken since two missions to check the status of logging there from 1996 onwards. on the Nakai Plateau and concluded that there has been no logging in the com- munity forest areas or in the NBCA. (NTPC and WB) Concerns about the livelihood model. Japan Volunteer 1) Villagers have decided to stay on the Nakai Plateau and this has implications 1) How will the resettlers be able to grow rice? Centre for their livelihoods. Resettlers are not encouraged to grow rice but the cultural importance of rice and food security are recognised. However, in the long-term, 2) Where are the markets for cash crops? alternative crops on irrigated terrace will be developed. (NTPC) 3) Where are the grazing areas located? 2) Studies are being carried out at present in order to identify the best cash crops for commercial markets in the region. (NTPC) 3) Grazing areas will include the drawdown zone of the reservoir and in the resettle- ment zone. (NTPC) Project cost unclear and there is inconsistency in the Friend of the Earth, 1) Maximum or full supply level (538 masl.) will be 450 sq km. The reference to the data as presented in the report: France 650 sq km., which represents the total area of zone 1,will be removed. (NTPC) 5 1) Surface inundated unclear (650 or 450 ref. SESIA?) 2) The number of people to be resettled is estimated based on population surveys 2) Number of people to resettled unclear (5,700 and projected numbers. The present estimate is 6,200 people, which includes -6,200) Project Construction Lands. (NTPC) Number of people affected downstream unclear 3) Livelihood options have been tested and developed since 1996 in the demonstra- (40,000 ­ 150,000) tion farms and later in the pilot village. (NTPC) 3) Livelihood options have not been sufficiently tested 4) Relevant sections of the CA and a summary of the PPA are already public and this involves a high risk for the plan. documents(NTPC) 4) Request full disclosure of PPA and CA for public Public review. 1) Studies used for the development of alternatives World Wildlife Fund 1) Reports (experiences) from Nam Ngum and Ubon Rattana reservoirs form the fisheries in the XBF and of the Reservoir fisheries? (WWF), France basis for the analysis of reservoir fisheries, is presented in Ch. 24 of the SDP. XBF 2) What is the relation to WCD? fisheries is still being analysed and will be completed before appraisal. (NTFP) Consultation 2) The WCD Report does not have any legal status but is a document considered useful by donors and planners for hydropower development. Lessons learnt and recommendations have been taken into consideration in the revision of safeguard documents. (WB/ADB) Nam Ngum fisheries experience has shown that it CNRS, France The reservoir fisheries association intends to ensure that benefits reach affected is necessary to exclude outsiders in order to ensure communities. A decree will give exclusive rights to resettlers. (NTPC) benefits to the local people. Monks should participate in the social development of Friends of Laos As- Cultural and religious concerns will be taken into account during the resettlement the Nakai Plateau sociation, France and there are provisions for improving existing temples and establishing new struc- tures at the new sties. (NTPC) Concerns about the risk of sedimentation in the reser- Fin-enviro Paris The sedimentation in the reservoir is anticipated to be very limited due to the protec- voir and dust generation in the drawndown zone. tion of the forest cover in the watershed. The drawndown zone is likely to become a grazing zone during the dry season. to allow international stakeholders, including NGOs, govern- · Organising visits by concerned groups from Pak Mun in order ments and donors, to voice their opinions and concerns. Anumber to allow open discussions and interactions between affected per- of presentations were made specifically on project environmental sons from NE Thailand and Nam Theun 2 Project Affected Per- and social impacts, mitigation, and the consultation process. A sons ­ the aim would be to allow the exchange of information and wide range of queries and opinions were expressed during these improve reselement plans; discussions. Table 5.8 summarises concerns and issues raised and · Completionofstudiesonmarketsforagriculturalproductsand the related responses. Full records from the international work- starting additional studies in order to obtain a beer understand- shops are available in the moderators' reports and news releases ing of potential markets for cash crops in the region and ensure that have been produced for each of the workshops. income for reselers; A number of important issues were raised during the discussions · Inconsistencies regarding population figures, reservoir size at the workshops and the following aspects will be acted upon in and other aspects in the EAMP, SDP, SEMFOP-1 and SESIAwill be order to enhance existing plans and initiatives: made removed; The PCD Process 179 EAMP Main Text EAMP Main Text Table 5.9: Disclosure of past and future drafts of the EAMP Month Year Version Disclosure Consultation May 1997 First draft EAMP Yes Yes November 2000 Second draft EAMP Yes Yes April 2001 Third draft EAMP Upon request No March 2003 Fourth draft EAMP Upon request No October 2003 Fifth draft EAMP Limited Distribution No March 2004 Advanced draft EAMP Disclosure to the Public Yes October 2004 Final EAMP Disclosure at the WB info shop Yes · Completion of analysis on fisheries in the NakaiReservoir and NTPC Project Information Centres at Vientiane, Thakhek, and Xe Bang Fai; Nakai. · Enactment of a decree which will clearly ensure that the land Upon completion of the dra EAMP in November 2000, a public and forest resources of the reselement area, and the fisheries announcementwasmadeinlocalnewspapers.Thiswasinaddition resources in the reservoir, are for the exclusive use of the Nakai Plateau reselers; to the notice given at the provincial and district levels, and direct · Further investigation of the potential to raise buffaloes and cat- invitations to more than 200 persons. One hundred and eighty- tle in the reselement areas, and drawdown zone. nine persons aended the national level workshop in Vientiane in November 2000 where the findings of the EAMP were dissemi- More generally, the workshops allowed GoL and NTPC to beer nated amongst an audience that included Project affected people, assess the general opinion on, and the level of preparedness of, the Project's social plans. It also emphasized the need for continuous community leaders, the LWU, the World Bank, Government agen- monitoring during the implementation period. cies, and other interest groups. The workshop included interactive displays of the reselement areas and of the demonstration and Public Disclosure agriculture extension farms. Major reports were available at these 5 meetings. Group discussions and question and answer sessions Throughout Project planning, NTPC has made available copies of key reports and dra Project environmental and social documents. followed the presentations. Atechnical resource person and a rep- The Project website (www.namtheun2.com) has also disseminated resentative of NTPC were available at each session to facilitate and information and includes an email link for Project feedback. There to answer inquiries from the participants. are several key documents that include specific information relat- Public Disclosure on Project Approval ing to public participation; these include the Study ofAlternatives, the EAMP, the SDP and the SEMFOP. NTPC will conduct the following public disclosure on Project Detailed below is the disclosure process for the Study of Alterna- approval: tives and the EAMP; the disclosure process for both the SDP and · During the construction phase the HC will disseminate infor- the SEMFOP can be found in those respective documents. mation regarding construction progress to the stakeholders in collaboration with NTPC and local authorities; Environmental Assessment & Management Plan · Grievanceresolutionmechanismswillbeputinplacetoensure Since 1997, public participation has been integrated into Project thatpotentialproblemsareaddressedpromptlyandefficiently. Consultation planning.Asaresulttherehasbeenactiveparticipationandexpres- The procedure is set out in the SDP; sion of views on the environmental aspects of the Project at local, · The reports of the findings of the POE will be made publicly regional, national and international levels. There were two formal available; and Public national public consultations, in March 1997 and November 2000, · Throughout the Project implementation, NTPC will provide a symposium in Vientiane in 2002, and several international work- PAP with information on all aspects of Project development. shops in September 2004. Comments from these consultations This will be distributed through the existing Information Cen- were incorporated into the EAMP documents. Table 5.9 presents tres and other avenues such as the Reselement Commiee, the past and proposed future versions of the EAMP. the offices of the EMU, and the Project Grievance Commiee. Alternatives & Economic Impact Studies NTPC will continue to record the ongoing consultation activi- ties that have been organised. The Study of Alternatives included an intensive participatory approach to the identification and weighting of criteria for assess- ing the suitability of various alternatives as presented in Chapter Stakeholder Input into Project Design 2. Public consultation as part of the Study of Alternatives was con- ducted using three workshops held in January, May and July 1997; Issues Raised by Independent Reviewers & Project the Study of Alternatives was also the subject of discussions dur- Responses ing the series of international workshops in September 2004. These workshops brought together NGOs registered in the Lao PDR, The PCD process has benefited from the continued advice and international NGOs, local ministries, district and government offi- review of a host of international experts. Regular independent cials, donor agencies, academic institutions, embassies and energy reviews by the International Advisory Group (IAG), the Panel of sector representatives. Experts (POE) and the Dam Safety Panel of Experts (DSPOE) have Public Availability of Reports shaped the direction and enhanced the quality of planning and decision making. Annex O discusses the scope of work and the At various times during Project implementation, NTPC has issued independence of these international experts, and highlights some public notification of the availability of Project reports through of the suggestions made. 180 Stakeholder Input into Project Design Public ConsultationEAMPDisclosureand Main Text Table 5.10: Stakeholders concerns and influence on Project planning Topic Stakeholder Concerns Influence on Project Planning Benefits for Lao Logging in the NNT NBCA. The Project will contribute a total of US$ 31.5 million to the management and conservation of the NNT NBCA to protect its natural resources. EIA process Slow progress of Project development. The Project is being developed in line with WB and ADB policies, and so takes time. Erosion Erosion effects and control mechanisms in the The majority of the Downstream Channel will be lined and the confluence with the Xe Bang Fai Downstream Channel. protected to help minimize erosion. Potential sedimentation problems in the An analysis of sedimentation concluded that with current rates of erosion, the loss of storage in Reservoir. the Reservoir would be minor. Fisheries Impacts on the downstream families who are Aquatic resources and socio-economic surveys will quantify the loss of livelihood. Proactive com- dependent on fisheries. pensation plans are presented in the Xe Bang Fai strategy of the SDP. Lessons learnt from similar projects in terms of Lessons learnt from the Theun Hinboun hydroelectric project have been used to develop the the effect on fisheries. mitigation and compensation measures for the Xe Bang Fai. Past experience in other projects has been used to estimate the productivity of the reservoir fisheries in an assessment for livelihood options for the resettlers. Flooding Increased flooding in the Xe Bang Fai in the wet The Project will reduce then stop generation to prevent any additional over bank flooding. In the season and less water in the dry season. dry season a reliable water resource will be available in the Xe Bang Fai for irrigation. Geology Impact of the Reservoir on the geology. The geology of the Nakai Plateau has been assessed and it was concluded that there should be no impacts in terms of stability and water tightness. Health Health impacts during construction. The Project shall implement three health programs (Regional, Resettlers and Construction Workers) to strengthen local health facilities and to educate communities on potential health risks. Land issues Compensation for loss of land and assets. A survey is being conducted to identify how much of the land is required for construction. The framework for compensation is presented in the SDP. Natural Habitats Hectares lost and gained as a result of the The Natural Habitats accounting study quantified the areas and habitat types that will be lost or 5 Project. conserved as a result of the Project. NBCA Resettlement sites or the reservoir encroaching The proposed resettlement area is on the southern side of the reservoir and the boundary for the on the NNT NBCA. NNT NBCA is the El 538 m contour. Therefore neither the inundation of the reservoir nor the resettlement area will have direct impact on the NNT NBCA. PCD Communities understanding the nature of the The PCD process utilizes appropriate media and language, taking into consideration the needs of impacts. vulnerable groups such as women and ethnic minorities. PCR Impacts on artifacts, historical places and Two separate surveys were conducted to determine the presence of existing cultural resources handicrafts. within the Project area. An additional survey is being undertaken and will be completed by August Public 2004. Study of Alternatives Power supply options within Thailand need to The Study of Alternatives analyzed the generating options and demand in Thailand. The study be determined. concluded the demand was strong enough to accommodate 3,300 MW of exports from Lao PDR and the Project can easily compete with the most attractive power supply options in Thailand. Consultation Need to study other alternatives for short and The Study of Alternatives analyzed the other candidate power export schemes for Lao PDR and long term development of Lao PDR. concluded the Project ranked as one of the most attractive proposals. Technical Design Impacts of reduced flow downstream of the The Riparian Release study will evaluate the impacts of reduced flows and spills downstream of the dam. Nakai Dam, then make recommendations on management options for the flow regime and chan- nel modifications to minimise impacts. The report is expected in June 2004. Minimization of resettlement and compensation A Downstream Channel will be constructed instead of releasing water into the Nam Katang, downstream of the Power Station. reducing the number of households that would be affected, plus providing opportunities for gravity irrigation. Minimization of resettlement and compensation Construction and upgrading of roads will follow existing road alignments and avoid inhabited for new roads. areas. Minimization of resettlement and compensa- A Regulation Pond will be constructed to regulate flows and thus avoid unnecessary negative tion regarding water releases from the Power impacts along the Xe Bang Fai communities. Station. Transmission Lines Safety of the transmission towers and compen- The towers are designed to be structurally safe and withstand adverse weather conditions. Analysis sation for loss of houses or fields. of magnetic and electric fields has been carried out. The baseline survey will identify those persons eligible for compensation. Water Quality Remaining biomass in the reservoir. Ongoing satellite imagery interpretation and ground truthing will assess the current biomass in the inundation area and recommend measures to target the removal of the remaining biomass to help improve water quality. Water quality downstream of the Power Station A monitoring program will assess whether any adverse changes in groundwater and surface water for domestic users. quality are potentially harmful to human health. NTPC will provide alternative sources of house- hold water, especially in villages where surface water is indicated as their primary domestic water source and this water is not suitable for human consumption. Wildlife Fate of rare animals. Various wildlife programs are being established to monitor and conserve threatened and endan- gered species. In particular, programs will initially focus on the protection of the two key species: the elephant and the white-winged duck. Institutional Arrangements for PCD Process 181 EAMP Main Text EAMP Main Text Table 5.11 Review of PCPP by Franklin (1997) Issues Raised Integration Into Project Development A Senior full-time Social Scientist is required for PCPP Planning Since this review a Senior Social Specialist has been involved in PCPP Team Training, developing a PCPP and Management. plan and managing its implementation. On approval of the Project for funding/financial close, a full-time appointment will be made. Village facilitators need to be identified and smaller group In the Plateau villages, representative Village Resettlement Committees have been formed to coordinate discussions pursued for better representation of stakeholders. village activities and continue village consideration and planning for resettlement for integration into the RAP. In the other impact areas, consultation programs have included focus group discussions and individual interviews with villagers in order to identify village facilitators. PCPP techniques have expanded to incorpo- rate smaller group discussions and interviews ensuring representation of all gender, ethnic and generational groups. PCPP Teams should be ethnic and gender representative of the PCPP Teams have always included ethnic (Brou, Lao Kaleung, Phu Thai and other groups) and women `s stakeholder populations. groups. Messages and materials need to be developed more specifically Extensive planning has produced materials that are targeted at the various stakeholders, in particular post- for target audiences. ers, pictures, diagrams, drawings, videos and other means that take account of the literacy levels. PCPP Teams require further training. Training in participation techniques was conducted in 1997 and 1998. Further training is proposed for the RMU and others involved in the resettlement process. Influence of Consultations on Project Planning past activities, and identified gaps between local consultation Feedback from stakeholders has been incorporated into and has undertaken and the relevant World Bank policies. A summary of influenced Project planning and design. The following Project the findings and the integration of the recommendations into the design features can be aributed to input that has resulted from ongoing PCD process are presented in Table 5.11. public consultation. Table 5.10 summarizes the influence of the In 2002, the Public Consultation and Participation Process (PCPP) participation process on Project design. was renamed as Public Consultation and Disclosure (PCD), with · The Power Station and substation are to be located in a place the consultation component of the PCD including the participation of stakeholders from the PCPP. 5 where there are no villages, thereby avoiding the need for reselement; · The Downstream Channel represents a substantial additional Institutional Arrangements for PCD Process cost and an alternative to channelling the water into the Nam Kathang. The current design of the Downstream Channel min- GOL has, and will continue to take the lead role in the PCD proc- imises reselement and social impacts and maximizes devel- ess, with NTPC providing technical and managerial support as opment potential. Detailed routing was based on the results of required, and the World Bank andADB assisting with engagement consultations with people directly affected. The channel is to of experts in the fields of participatory consultation. be lined and partially above natural ground level, helping to With regard to village level consultations, the earlier consultations minimize width and land requirements. Irrigation outlets from (around 1997) were led by the GOLRMU. In the downstream area, the raised channel will enhance gravity-fed irrigation opportu- and due to the large number of villages, GOL formed teams, com- nities in the Gnommalat area; posed of the Reselement Working Groups, to visit each village for · The construction of a Regulating Pond shall minimize fluctua- consultations. These teams were given training in PRA by NTPC tions in daily discharge, and thus minimise erosion in the Xe hired experts. Consultation Bang Fai; The 2nd Phase of consultations, due to begin in early 2004, will · Bank protection at the Downstream Channel confluence with again be led by GOL, who will form its own Public Consultations the Xe Bang Fai will prevent erosion; Office. For village level consultations and disclosure, the RMU will · Construction of aeration structures, in association with the form a Participatory Consultation and Disclosure Unit. This unit Public Regulating Pond and Downstream Channel, will help ensure will manage the consultation and disclosure process, and assist the quality of water for downstream areas; the District level staff with forming teams to work in villages. As · A guaranteed minimum flow into the Downstream Channel required, the unit will also ensure that technical assistance is avail- shall help sustain any fish populations that may develop; and able in topics relevant to the PAPs, such as rural livelihoods, health · Operational shutdown before natural over bank flooding care and community development. occurs in the Xe Bang Fai, shall prevent the Project to exacer- NTPCwillalsoformateamofnationalandregionallevelconsulta- bate natural floods in terms of height or frequency. tions officers, to liaise with, support, and where necessary provide Influence of Consultations on Resettlement Issues training and actual assistance in the field to GOLPCD units. NTPC PCD staff will identify any gaps in the process and recommend Selection of reselement sites, livelihood models, housing styles measures to improve any deficiencies. They will conduct work- and other infrastructure recommendations occurred with careful shops to review and strengthen local staff capabilities in PCD, and consideration of the current living and livelihood paerns of the help the field teams to develop strategies and working methodolo- affected persons. The role of the Reselers in the selection and gies. They will assist the RMU in managing all processes. preparation of reselement sites, village configuration, house A crucial role of NTPC will be to coordinate and ensure that GOL design and pilot village activities is outlined in the SDP. PCD Units are provided with, and understand, the full range of Influence of Consultations of the PCD Process information relating to the Project. NTPC will plan a recurrent set of training sessions to ensure GOL staff are fully conversant in the As with the consultation of Project design, the development of the Project. In addition, the NTPC PCD team will be primarily respon- PCD process has also been open to review and consultation. In sible ­ in close cooperation with the RMU ­ for the production of 1997, a review of local public consultation was conducted. Fran- posters, maps, photos and translation, facilitation manuals and klin (1997) identified the needs for local consultation, reviewed any other consultation materials and tools. 182 Institutional Arrangements for PCD Process Public ConsultationEAMPDisclosure and Main Text Not withstanding the above general institutional arrangement, the actual responsibilities for, and content of any particular consulta- tion and disclosure depends on the timing and the target audi- ence. 5 Public Consultation Institutional Arrangements for PCD Process 183 EAMP Main Text EAMP Main Text 5 Consultation Public 184 Institutional Arrangements for PCD Process EAMP Main Text 6. Environmental Management Plan Key Organisations in the Environmental Management of the Project 186 NTPC Environmental Management Office 186 The Head Contractor 186 GOL Organisations 188 Management of Impacts 192 Mitigation Measures to be implemented by NTPC 192 Mitigation Measures to be Implemented by the Head Contractor 195 Mitigation Measures to be Implemented by GOL Organisations 200 Implementation of Mitigation Measures 201 Provisions of the Concession Agreement 201 Funding & Responsibilities for Implementing the Environmental Management Plan 201 Monitoring 202 Adaptive Management 204 EMP T he first part of this chapter describes the organisations within NTPC, the Head Contractor (HC) and GOL that will be responsible for implementing the mitigation and com- pensation measures and the monitoring of their implementation. The mitigation measures are summarised in the second part of this chapter. The final part of chapter six details how the mitigation measures will be implemented. The mitigation and monitoring measures to be implemented during the Project construction phase are presented in Annex L. The social impacts stemming from the Project are mitigated through the provisions of the SDP. Similarly, the mitigation measures for the environmental and social values relating to the watershed are described in the SEMFOP. Key Organisations in the Environmental Management of the Project 185 EAMP Main Text Figure 6.1: Key organizations Key Organisations in the Environmental · Conducting appropriate testing to ensure that the environ- Management of the Project mental mitigation measures are effective; · Arranging for reporting of the results of the monitoring pro- The key organisations responsible for the implementation of the grammes; various mitigation measures are: i) the Environmental Manage- · Maintaining records for reporting to GOL and the EMU; ment Office (EMO) of NTPC; ii) the HC; iii) GOL organisations · Preparing budgeting and financial reports for the operation of including the Science Technology and Environmental Agency the EMO; (STEA), the Environmental Management Unit (EMU); and the · Conducting internal and external audits to ensure compliance Watershed Management and ProtectionAuthority (WMPA). These with the CAand the procedures of NTPC; and organisations are shown in Figure 6.1. · Assisting GOL with the public consultation programmes and documenting the feedback for incorporation into programme NTPC Environmental Management Office planning. Throughout the construction period, the EMO will prepare The EMO will be responsible for the technical planning, imple- monthlyreportsforsubmissiontoGOL.Thesereportswilladdress mentation and monitoring of all environmental mitigation and the following items in relation to the EMO responsibilities outlined compensation measures under NTPC's responsibility, as required above: by the CA. In addition the EMO will monitor the implementation of mitigation measures that will be supervised and carried out by · Progress made to implement the environmental mitigation the HC and the Construction Contractors. This monitoring will measures in compliance with both the CAand the HCC; ensure compliance with environmental provisions of both the · Schedule of implementation of environmental mitigation CA and Head Construction Contract (HCC). The EMO will work measures; closely with the EMU and other GOL agencies, as appropriate. · Any difficulties with implementing the environmental mitiga- tion measures and recommendations for correcting the prob- Prior to the start of the Construction Phase, the EMO will: lems; and · Ensure that the relevant environmental mitigation measures · Anyaspectthatdoesnotconformwiththeenvironmental miti- are reflected in the Project Contract, including the HCC; gation measures and proposed remedial measures. · Prepare plans for mobilising subcontracts for studies that will be conducted by NTPC; The Head Contractor · Hold discussions with the government authorities participat- The HC will be responsible for implementation of measures to ing in the Project, such as the WMPAand the EMU, to develop avoid or minimise environmental impacts during construction. procedures for inter-agency coordination and reporting; Examples of aspects these measures relate to are: · Ensure that the Construction Phase activities include appropri- · Meeting effluent standards and water quality requirements for ate environmental monitoring; discharges into surface waters and groundwater; · Assist the EMU to plan and manage the environmental public · Controlling drainage, erosion and sedimentation; consultation and information programme; and · Protecting physical and cultural resources; · Provide any necessary background information to the EMU to · Landscaping, rehabilitating and re-vegetating the construction EMP enable response to public comments, complaints and inquiries areas; in relation to the environmental mitigation measures. · Managing on-site waste; During the Construction and the Operating Phases, the EMO will · Managing use and storage of chemicals, preventing and devel- be responsible for implementing and monitoring environmental oping emergency plans for chemical pollution incidents; mitigation measures. The management of environmental concerns · Controlling noise emissions and dust from construction activi- will include: ties; · Surveying, detecting, and rendering safe by removal and sub- · Developing and implementing the monitoring programmes; sequent destruction (or by in-situ destruction) of UXO; · Managing the subcontracts for specialist studies to ensure their · Designing and constructing construction work camps, includ- performance; ing planning and provision for spontaneous reselement; · Liaising and cooperating with the government authorities · Implementing a programme for construction worker educa- given responsibility for implementing GOL's responsibilities; tion in environmental issues; · Preparing work and cost schedules for the monitoring pro- · Implementing a health and safety programme for all persons grammes; engaging in construction works; and 186 Key Organisations in the Environmental Management of the Project EAMP Main Text · Managing the impoundment of the reservoir. The HCC EMMP documentation The provisions of the HCC between NTPC and the HC includes · Providesthe EnvironmentalPolicyofthe HCandConstruction the HC's obligations for undertaking measures to minimise and/or Contractors dedicated to the Project; mitigate impacts on the existing environmental and social condi- · Addresses HCC and regulatory requirements; tions.In addition to theseresponsibilities,theHCisresponsiblefor · Provides operational and emergency procedures, developed supervision of Construction Contractors. Both the HC and Con- to address the environmental aspects and risks related to the struction Contractors will have environmental staff to carry out construction period of the Project; their respective responsibilities. · Provides for the implementation and operation of the EMMP to ensure that structure and responsibilities are assigned, staff The HCC Environmental Management and Monitoring Plan is trained, aware and competent, and that there is proper com- The primary document for implementation of the above measures munication, documentation, operational control and emer- is the Head Construction Contractor's Environmental Manage- gency preparedness and response. ment and Monitoring Plan (HCCEMMP). The HCCEMMP covers · Provides organisational and technical procedures for imple- mentation of the EMMP which ensure that construction activi- environmental measures listed above, and contains an overview of ties associated with potential environmental impacts are car- the Project impacts that the HC's work will have on the physical, ried out in a controlled and responsible way. biological and social environment. · Provides checking and corrective action through monitoring The preparation and implementation of the HCCEMMP is one of and measurement. the Environmental and Social Objectives of the CA, and is covered · Provides records collection and storage, and program audit; by the Project performance guarantees. Failure to respond appro- · Includes Management Review of the EMMP and enables priately is covered in the CA under the provisions for a breach or improvements to be incorporated in the Plan. failure to implement any of the Environmental and Social Objec- The HCC EMMP is to be submied as a Preliminary Dra version tives (Clause 30 of the CA). nine months before the Project Commencement Date. A Dra ver- The HCC EMMP is structured in three parts: sion is to be submied six months prior to the Commencement Date, and a Final version provided for approval four months · A Master EMMP, which provides organisational and opera- before Commencement Date. tional procedures for the implementation of environmental measures (Part A); HC Monitoring and Auditing · Sub-Plans, which describe the environmental measures in The HC is responsible for monitoring and assessing how environ- terms of subject ­ such as sediment and erosion control, noise mental management at each site, and for the entire project, is per- control, etc, including responsibility for implementation, tech- forming. To do this, the HC is responsible for monitoring environ- nical details and how implementation is monitored (Part B); mental controls employed at each site, and environmental aspects · Site Specific Environmental Plans, which provide for each con- of their construction activities in general. struction site or camp area a description of the area, how the The HC is required to carry out routine monitoring of construction environmental measures will be adapted to the site, and the sites and construction activities in order to ensure that require- design of typical measures (Part C). ments and measures specified in the HCCEMMP are implemented EMP Figure 6.2: HCC EMMP structure Key Organisations in the Environmental Management of the Project 187 EAMP Main Text Figure 6.3: EMU overall organisation and impacts are minimised or mitigated. This will be on a site- In addition, periodic auditing will take place. An audit will be by-site basis, and is intended to be continual and frequent. This undertaken two months aer construction has commenced at includes physical monitoring, such as water quality sampling, air each site, and six-monthly audits will take place aer that. The six- quality monitoring, waste tracking, and tracking amounts of haz- monthlyauditswillalsoincludeenvironmentalperformanceatthe ardous chemicals in use and to be disposed. organisational level. Audits are intended to be periodic reviews to The HC will employ specialist environmental staff to undertake verify conformance. this monitoring. Staff will be selected on the basis of environmen- Together, monitoring, non-conformance systems and auditing will tal training, skill and experience. allow evaluation of environmental performance; analysis of root The HC will utilise reporting and non-conformance systems to causes of problems; assessment of compliance with contractual ensure that corrective action is taken where necessary, and to track and legal requirements, and enable identification of areas requir- environmentalperformance.Thenon-conformancesystemwilluse ing corrective action. three levels of non-conformance to prioritise action according to The HC will be required to identify and document in the importance, severity and internal communication requirements. HCCEMMP the specifics of what monitoring and measurements The non-compliance procedure described above allows the follow- will be performed, and specify the allowable range of results. It ing safeguards: will also be required to identify the frequency, locations and per- sonnel performing the monitoring and measurement. The HC will EMP · work can be stopped in the event of a serious non-compliance situation; also be required to maintain quality control procedures for these · follow-up visits to the sites of observed non-compliance inci- activities. Environmental monitoring by the HC will be required to dents are required to verify that the situation has been appro- conform to the requirements of ISO14001. priately rectified by the Construction Contractor; Also clearly defined will be the International Standard Quality · incident investigation to determine the root causes of signifi- Assurance (QA) procedures to be followed to ensure these obliga- cant incidents and evaluate if changes need to be made to the tions are met. There will be periodic independent external audit- EMMP or other documentation to prevent similar incidents ing of these QA procedures. The HC will also be required to have from occurring in the future; and an environmental management system in place in full compliance · In the case that environmental impacts are caused before with ISO 14001. the non-compliance is observed, rectified and completed, the Construction Contractor responsible will be requested to GOL Organisations implement appropriate actions to mitigate any impact already Under the CA, a number of GOL organisations will be responsi- observed. ble for implementing mitigation, monitoring and management 188 Key Organisations in the Environmental Management of the Project EAMP Main Text Table 6.1: Environmental management tasks to be undertaken Task Implementation Coordination Site Monitoring Oversight Funding Compliance with environmental construction obligations Construction sites management according to HCCEMMP Contractors EMO Contractors EMO & EMU Contractors Resettlement and downstream livelihood activities not included in HCC Contractors and parties EMO Contractors EMO & EMU Contractors and employed by RO NTPC Control of spontaneous settlement Provinces / Districts Provinces Districts RC Provinces Prevention of building near to transmission lines Provinces Provinces District District Province Adaptive ecological management Fish impacts in upstream and downstream rivers Consultants and GOL EMO Consultants and EMU NTPC agencies GOL agencies Terrestrial animals in the inundation area Consultants and GOL EMO Consultants and EMU NTPC agencies GOL agencies Asian Elephant programme Consultants and GOL EMO Consultants and EMU NTPC agencies GOL agencies Transitional strategy for reservoir impoundment Consultants and GOL EMO Consultants and EMU NTPC agencies GOL agencies Wetland conversion and formation Consultants and GOL EMO Consultants and EMU NTPC agencies GOL agencies Water quality program and downstream hydrological impacts Consultants & NTPC EMO Consultants & EMU NTPC EMO Reduction of shifting cultivation RMU RMU RMU Province SDP budget GOL wildlife and vegetation activities Hunting and wildlife trade control and outreach PAFOs, DAFOs & police EMU PAFOs, DAFOs EMU EMU budget & police Salvage logging in reservoir Khammouane PAFO, Province District Province Nakai DAFO components during construction and operation of the Project. The Project.STEAconsistsofseveraldepartments:ScienceandTechnol- following descriptions provide the general responsibilities of the ogy, Intellectual Property, Environmental and several Technology agencies within GOL for implementing these measures. Research Institutes. The Department of the Environment within National Environmental Committee STEA has responsibility for acting in the role of Secretariat to the National Environmental Commiee and also for coordinating the An inter-ministerial working group for the environment was interaction of the environmental sections of the other Ministries. established in 2002 and is known as the National Environmental STEA has the prime responsibility for coordinating the environ- Commiee. Members of the National Environmental Commiee include representatives from the Executive Branch (Deputy Prime mental policies of the other Ministries within GOL. For example, Minister), MAF, the Director General of STEA, and Vice-Ministers the MIH is responsible for requiring electricity project developers of the Ministry of Commerce and Tourism, the Ministry of Indus- to provide a Social Impact Assessment, an Environmental Man- try and Handicras, the Ministry of Public Health, the Ministry of agement Plan and implementing an Environmental Assessment Interior, the Ministry of Justice, the Ministry of National Defence, pursuant to the Electricity Law. Although the MIH is involved in the Ministry of Education, the State Planning Commiee and the this process, it is STEA that will determine if the electricity devel- Ministry of Communications, Transport, Post, and Construction. oper has met the environmental requirements outlined in the Envi- ronmental Protection Law and the Regulations on Environmental The objective of the National Environmental Commiee is to Assessment. advise the government on the management and protection of the environment and to coordinate the development of environmen- The operational experience of the STEA staff is, for the central tal management and monitoring plans across the Ministries and ministry at least, extensive. A number of the directors and staff EMP at the local government levels. The implementing agency for the have been involved in the planning, construction and operation National Environmental Commiee is the Secretariat. This office is of hydropower projects in Lao PDR including Theun Hinboun, responsible for reviewing environmental assessments of proposed Houay Ho, Nam Ngum 3 and Nam Leuk. projects, advising the National Environmental Commiee relative Each of the provinces in Lao PDR has STEA offices that work to environmental issues, disseminating information, and promot- under the Provincial Governors' Offices. Although a Provincial ing implementation of provisions of the Environmental Protection Governor's Office is involved in all decisions relative to develop- Law. The Secretariat is also responsible for coordinating local gov- ment in the province, oen their participation is limited to one or ernment organisations relative to environmental management and a few people. monitoring. The head of the Secretariat is the Director General of the Department of the Environment within STEA. The Environmental Management Unit The Science, Technology & Environment Agency Under the direction of STEA, GOL has established an EMU that will be responsible for the implementation and management of STEA will have a major responsibility relating to implementation the environmental components of the CA. The EMU will be spe- of mitigation and compensation measures associated with the cifically designed for the Project and will consist of representatives Key Organisations in the Environmental Management of the Project 189 EAMP Main Text Table 6.2: Key tasks and responsibilities of EMU teams Team / Organisation Responsibilities Key Tasks STEA NT2 Committee EMU directorship · Convene quarterly to review EMU progress reports and at other times as necessary. · Provide advice to EMU on the execution of their duties and approve workplans and budgets. Policy setting · Formulate policy recommendations to resolve novel issues arising among different GOL authorities and the Company relating to environmental measures. · Advise NT2 Steering Committee on the adequacy of environmental measures and recommend amend- ments as required from time to time. Coordination with GOL · Consult with affected ministries and other GOL authorities over new policy proposals. authorities · Allocate roles and responsibilities of relevant GOL authorities to assist GOL in achieving objectives. · Coordinate with GOL authorities in implementation of Environmental Objectives of GOL and NTPC. · Coordinate between GOL authorities and NTPC. Coordination and Strategy Admin and management · Establish effective systems for managing EMU financial resources. Team · Develop and update annual work programmes. · Develop performance indicators. · Organize and implement capacity building programme. · EMU performance monitoring. · Facilitate visits of POE and other environmental oversight, IAG, IMA and other monitoring groups. · Organize appropriate TA. · Prepare and issue 6 month progress reports to the NT2 Committee of STEA on the basis of reports submit- ted by the technical teams and the progress of the Coordination and Strategy team's own activities. Policy coordination · Provide policy recommendations to the STEA NT2 Committee, drawing on findings of technical teams and expert opinion within and without STEA as appropriate. · Advise the STEA NT2 Committee on the adequacy of environmental measures and recommend amend- ments as required from time to time. Communications · Liaise with external organizations (NGOs, media) in relation to environmental issues. (Vientiane) · Establish and maintain national project information center. (Vientiane) · Facilitate public inputs, feedback at national level. (Vientiane) · Mobilize public information campaigns. · Establish and maintain provincial project information center. (Khammouane) · Conduct periodic briefing sessions for provincial and district officials on environmental progress (Kham- mouane) · Facilitate public input and environmental grievance process at the local levels (Khammouane) Compliance Team Compliance with · Review and approve environmental component of HCC and the HCCEMMP. environmental obligations · Review and approve environmental aspects of resettlement construction activities. · Review and approve or provide NOL of EMO field activities. · Verify monitoring of environmental obligations of GOL and NTPC at the field level through accompany- ing EFI and/or EMO field visits; carrying out independent spot checks; and parallel and/or additional sampling as appropriate (Khammouane) · Periodic briefings with provincial RO (Khammouane) · Issue monthly reports on project progress to Coordination and Strategy team. Ecological Management Team Adaptive ecological · Review plans for wildlife studies, fisheries monitoring, water quality monitoring and emergency wildlife management management measures. · Review progress reports from each of these components. · Review and approve adaptive management response proposed under each component on the basis of data collected. · Conduct periodic briefings with implementing teams (Khammouane) · Verify the quality of research work through periodic field visits, local consultation, and parallel and/or ad- ditional sampling where appropriate (Khammouane) · Issue monthly reports on project progress to Coordination and Strategy team. GOL wildlife activities · In consultation with local implementing authorities and the WMPA, produce plans for measures to address wildlife trade issues around the Project area, wildlife safeguards to be included in the salvage logging program, and vegetation removal in the inundation area (not including Special Conservation Areas) (Khammouane) · Coordinate the activities of local authorities in regard to each of these activities (Khammouane) · Review progress reports from local authorities in regard to each of these activities, and provide guidance on improving effectiveness. · Verify field activities and outcomes through accompanying local authorities staff on field visits, periodic EMP spot checks, and local consultation. (Khammouane) · Issue monthly reports on project progress to Coordination and Strategy team. from the MIH Hydropower Office, EDL, the Khammouane Provin- ing the construction and operational periods, as defined in the CA. cial Office, and the District Offices of Nakai and Gnommalat. The Responsibilities of the EMU include: representatives will be appointed by the respective organisations · Reviewing and approving the environmental specifications for and will be, where appropriate, expected to have prior experience the HCC; with hydropower planning in their respective organisations. · Coordinating the implementation of environmental mitigation The EMU will be responsible for implementing some of the miti- measures with GOL and NTPC; gation measures that are outside the NNT NBCA. STEA, through · Allocating responsibilities to other appropriate agencies to the EMU, will review reports of the monitoring programmes dur- assist GOL in meeting their obligations within the CA; 190 Key Organisations in the Environmental Management of the Project EAMP Main Text · Monitoring and supervising the implementation of the envi- NT2 Steering Commiee, provides senior policy advice, ensures ronmental mitigation measures for which GOL and NTPC are timely facilitation of activities and coordination at national and responsible. This includes the provision of non-objection or local levels. approvals for specific activities; · Appointment of an independent international monitoring Environmental management tasks outside of the Watershed agency to review the implementation of the environmental Table 6.1 shows the various tasks to be undertaken, broken down mitigation measures by GOL and NTPC and to facilitate man- by broad category and implementation arrangements, rather than agement of those activities; by detailed activity. All mitigation measures to be implemented · Conducting monitoring programmes to ensure that NTPC is by the HC are shown in brown, and those to be implemented in compliance with implementing environmental mitigation by NTPC are shown in pale blue with mitigation measures to be measures; implemented by GOL unhighlighted (black). · Advising STEA and the relevant government agencies on the adequacy of proposed environmental mitigation or compensa- Responsibilities and key tasks tion measures and recommending changes based on monitor- Key tasks and responsibilities for the STEA NT2 Commitee and ing results; EMU teams are outlined in Table 6.2. · Conferring with other organisations about environmental issues; Staffing arrangements and location of offices · Resolving environmental issues between government agencies It is proposed that the STEA NT2 Commiee is made of a maxi- and NTPC; mum of 5 senior staff of STEA. · Developing and updating the monitoring programmes for use The staffing of the EMU should follow the following. The Coordi- during the Construction and the Operating Phase; · Advising GOLthrough STEAon the effectiveness of mitigation nation and Strategy team will be made of 2 full time staff including measures; one national and one local communications and outreach special- · Coordinating necessary meetings between the NTPC EMO ist. The construction compliance team will be made of 2 full-time and appropriate government agencies; STEAstaff experienced in EIAand monitoring. Combined with the · Coordinating with the Panel of Experts and the International 1-2 full-time provincial staff, these will provide the core team for Advisory Group to assess the performance of the mitigation reviewing plans, and leading and directing field work. Additional measures; and provincial staff could be included in fieldwork according to need. · Providing technical assistance on any required input from the The ecological management team will be staffed by 2 full-time EMO and other government agencies. STEA staff, ideally one experienced biological and one in water quality field methods. Combined with the 1-2 full-time provincial The office of the main EMU is located at the STEA in Vientiane, staff, these will provide the core team for reviewing plans, day-to- with a field office in the Khammouane provincial STEAoffice. day coordination with local agencies, and leading and directing Overall organisation field work. Additional provincial staff will be included in field- work according to need. The EMU has a mandate to oversee all environmental aspects of NT2 project with the exception of management activities within Location: All work teams have some responsibilities that must the Watershed, which falls under the WMPA. be carried out at the local level, and significant work that at least could be carried out in Vientiane. It is inevitable that offices will The EMU will be made of a coordination and strategy team, con- be needed both at the central and local levels. The precise balance struction compliance team, and an ecological team, and will inter- of staffing between the two locations will be determined during act with the other GOL agencies and parties to the Project as indi- the inception period of the Technical Assistance Programme to the cated in the figure below. EMU. Core field staff, those involved in day-to-day coordination The Construction Compliance team is responsible for ensuring with local authorities, and local communications staff should be that all activities associated with project construction accord with located at the local level. The suitable location for staff involved in environmental obligations under the Concession Agreement, and reviewing plans and reports will depend on the locations of their in particular its Schedule 4, Part 2. The bulk of this work concerns principle NTPC and GOL counterparts and on the constraints that oversight of the EMO's compliance monitoring of the HCCEMMP, a base in Khammouane may place on retaining the best people. but it also includes verification of GOL obligations to minimize impacts of livelihood development activities falling outside of the The Watershed Management & Protection Authority HCC, and prevention of future construction near to transmission Management of most of the Project watershed will be under the lines. responsibility and management of GOL. To enable management of EMP The Ecological Management team has a similar oversight duty for the watershed, GOLestablished the WMPA. The WMPA's mandate the adaptive management programmes coordinated by the EMO, to operate in the Nam Theun 2 Watershed Area is legally defined but will also be represented on the commiees responsible for in PM Decree 25, which set out the areas as the NNT NBCA, the adaptive management decision-making. The second function of NNT ­ HNN corridor and the NNT ­ PHP corridor. This organi- the Ecological Management team is to liaise and coordinate with sation was established under the Prime Minister's Office and is the local authorities who will carry out field implementation of responsible for coordinating and managing all activities within the wildlifeandhabitatmanagementactivitiesaroundtheprojectarea. Watershed Area, including: This will imply liaison and coordination with the MAF, through · Conservation, maintenance and promotion of biological diver- the STEA NT2 Commiee. The EMU will have responsibility for sity coupled with the development of a national park appro- ensuring that these GOL activities are implemented in a coherent priate for tourism and scientific research; and effective way. · Building and strengthening the capacity of the WMPA; In addition to the two technical teams, the EMU comprises a Coor- · Facilitating improved livelihoods for inhabitants of the Nam dination and Strategy team and an overall director. The EMU Theun 2 Watershed Area to reduce poverty through environ- reports to the NT2 Commiee within STEA, which reports to the mentally sustainable development; and Key Organisations in the Environmental Management of the Project 191 EAMP Main Text · Protecting and rehabilitating forest cover in the Nam Theun 2 period. This complementary release is over and above the mini- Watershed Area to assure adequate water discharge with low mum riparian release (2 m3/s) and any natural spillage in times of suspended sediment. reservoir overflow. The WMPA will accomplish these functions through the SEMFOP NTPC's ability to vary the flow will therefore be the basis for a stra- and its operational plans. The WMPA includes a core component tegically focused Adaptive Management programme, which will of managerial and technical staff. The SEMFOP gives further target the maintenance and enhancement of aquatic productivity details on the organisation, function and planned activities of the in this stretch of the Nam Theun. The Adaptive Management of WMPA. the riparian release will involve a number of alternative discharge regimes from the dam to help ensure the aquatic system down- Management of Impacts stream from the dam will function properly. NTPC will implement a programme to monitor the water quality Mitigation measures were identified with the assessment of in the Nam Theun below the Nakai Dam (see measure above). impacts in Chapter 3. These measures are summarised below with a discussion of their objective, actions to be taken, and responsi- Responsibility: The intake structure, release structure and con- bility for their implementation. Mitigation measures to be imple- trols will be the responsibility of NTPC, supervising the detailed mented by NTPC are presented first, followed by measures to be design and construction by the HC. The EMO will be responsi- implemented by the Head Contractor during construction, and ble for monitoring and adaptively managing the release from the then measures to be implemented by GOL organisations. Nakai Dam. Mitigation Measures to be implemented by NTPC Aeration of Water in the Downstream Channel and the Nam Kathang Water Quality Monitory & Assessment Programme Objective: Increase the dissolved oxygen concentrations in the Objective: Monitor water quality in the Nam Theun and Xe Bang water discharged from the Power Station and decrease the concen- Fai, and some of their tributaries, and the Nakai Reservoir, and trations of methane and hydrogen sulphide. monitor groundwater in the Project area, during the pre-construc- Actions: The design of the Aeration Weir is part of the overall tion, during the construction and operation phases of the Project. design of the Downstream Channel. The design of the Regulating Actions: The water quality monitoring programme will deter- Dam will incorporate a hydraulic jump and simple weir into the mine baseline conditions in the Nam Theun and tributaries, Nam Nam Kathang. Kathang and Nam Gnom, Nam Phit and Xe Bang Fai, and ground- Responsibility: NTPC will be responsible for design, and the con- water in the Project area. The information obtained during this struction contractors will be responsible for construction of the monitoring period will be used to improve the water quality mod- aeration weir and the structures at the regulating dam. elling and to compare water quality conditions during construc- Downstream Channel In-Stream Degradation tion and operation of the Project. The monitoring programme (detailed in chapter 3) will assess Objective: Avoid and minimise in-stream degradation of the whether NTPC is fulfilling its goal of maintaining beneficial uses Downstream Channel during operations. of water within the Project area. The evolution of water quality Actions:NTPCwilldesign,constructandoperatetheDownstream aer inundation of the Nakai Reservoir will also be monitored. Channel to ensure an appropriate water velocity in regard to soil Results of the monitoring programme will be available for evalu- properties and the sediment load of water discharged from the ation relative to reservoir fisheries, the potential impacts of water Power Station. The Downstream Channel will be partially lined quality to fisheries in the Xe Bang Fai, and evaluation of impacts on from the regulating dam to the tunnel to minimise erosion. fisheries downstream from the Nakai Dam. In the Construction Phase, NTPC will ensure that the HC imple- Responsibility: The EMO will be responsible for implementing ments the appropriate design in construction of the Downstream the water quality monitoring programme from the pre-construc- Channel. In the Operating Phase, NTPC will monitor the per- tion phase through construction and the operating period. It has formance of the Downstream Channel and where bank erosion is to be noted that the HC is also responsible for preparing a Water detected, corrective measures will be implemented as appropri- Quality Monitoring Plan as a component of the HCCEMMP. The ate. Water Quality Monitoring Plan shall be designed to monitor the Responsibility:TheHCwillberesponsibleforthedesign and con- effects of surface water runoff and wastewater discharge from struction of the Downstream Channel. The design must include areas disturbed by all construction related activities. This is dis- the above features to avoid in-stream degradation. cussed further below. NTPC will be responsible for monitoring the performance of the Downstream Channel and correcting any incidences of erosion. EMP Riparian Release to Downstream of the Nam Theun Failure to respond appropriately is covered in the CA under the Objective: Minimise potential impacts on aquatic and terrestrial provisions for a breach or failure to implement any of the Environ- habitats relating to the damming of the Nam Theun, which will mental and Social Objectives (Clause 30). significantly curtail the natural flow of the Nam Theun below the Nakai Dam. Protecting Downstream Channel Fisheries Actions: NTPC will release a minimum discharge of two cubic Objective: Ensure that fish populations that may develop in the metres per second from the Nakai Dam into the Nam Theun (or Downstream Channel will be maintained through periods of low the equivalent volume of water as measured on a weekly basis). flow caused by low or no generation events at the Power Station. NTPC is obliged to use all reasonable endeavours to ensure that Actions:TosustainfishpopulationsthatmaydevelopintheDown- the minimum water is released in a continuous manner over the stream Channel during times when power is not being generated, course of each week. Additionally, the agreement provides for a a minimum flow of 30 m3/s will be maintained in the channel. This "Complementary Release", the aggregate quantity of which will release of water will be maintained unless the Power Station is not not exceed a total of five million cubic metres in any twelve-month operated for more than 32 hours on a continuous basis. 192 Management of Impacts EAMP Main Text Responsibility: NTPC will be responsible for management of stability will be protected by appropriate stabilisation or protec- the minimum flow as part of its operational management. Funds tion works. for monitoring will be from NTPC's operating costs. Failure to Where erosion of the Xe Bang Fai banks is apparent, an analysis respond appropriately is covered in the CA under the provisions will be performed to determine if repairs are required. The change for a breach or failure to implement any of the Environmental and intheriverchannelcapacitycouldaffectvillagesalongtheXeBang Social Objectives (Clause 30). Fai, so any erosion will be assessed on a case-by-case basis and the Prevention of Increased Flooding at Mahaxai appropriate action implemented. Further details regarding action to be taken is outlined in the Xe Bang Fai Strategy, produced by Objective: Avoid increased overbank flooding along the upper Xe NTPC in the SDP. Bang Fai due to additional waters from the Project through the timely cessation of electricity generation. A monitoring programme to determine any alteration in the rate of change in the morphology of the Xe Bang Fai channel will be Actions: The Project will operate in a manner such that overbank implemented by NTPC, in collaboration with the EMO and the flood events at Mahaxai are due only to natural causes. Release Reselement Management Office. of water into the Xe Bang Fai will stop during times of overbank flooding. Outflow restrictions will begin when flow in the Xe Bang Responsibility: The HC will be responsible for the design and Fai at Mahaxai approaches 1,970 m3/s. Outflows from the regu- construction of the confluence. NTPC will have the responsibility lating pond will be stopped sufficiently before the flow in the Xe for monitoring and evaluating any impacts, and for determining Bang Fai at Mahaxai reaches 2,270 m3/s, and in any event before the if remedial measures or compensation is necessary, as per the Xe Xe Bang Fai at Mahaxai overflows its banks. Bang Fai Strategy. In the Pre-construction and Construction Phases, NTPC will: Wildlife Management and Protection Programme · Install a data acquisition system for real time monitoring of The objective of the wildlife management programme is to mit- rainfall and river levels at, and upstream of, Mahaxai to enable igate, to the extent possible, the potential impacts on the Nakai flow to be monitored remotely at the Power Station; and Plateau wildlife. The assessment of potential impacts on terrestrial · Undertake further study to examine the appropriate trig- ecology has indicated that in order to develop an effective wildlife gers and operating criteria to ensure overbank flooding is not management plan it is necessary to understand the interactions aggravated. For both reservoir operations and power diversion between species and habitats and the overall ecological dynamics operations, development of appropriate flood forecasting pro- on the Nakai Plateau. This will be incorporated in the approach cedures is essential so that river flows can be predicted. used for the development and implementation of this programme. In the Operating Phase, NTPC will: Three main areas have been targeted: (i) upstream and down- · Maintain the data acquisition system, including stations stream rivers, with a focus on fish, (ii) the inundation of the Nakai upstream of the reservoir (all information will be recorded via Plateau and terrestrial animals impacted, (iii) wetland conversion telemetry); and formation. The entire wildlife programme will be adaptively · Monitor flows and rainfall in potential flooding periods at managed. Mahaxai. NTPC personnel will undertake this responsibility 1 - Fish impacts in upstream and downstream rivers with a direct communication link to the Power Station; and · Measure and monitor the flows in the Xe Bang Fai to ensure Amonitoringprogrammetargetingfishspeciesandaquatichabitat that the Power Station's operation management system for will be undertaken in the sections of the Nam Theun and Xe Bang flood control is based upon a maximum sample of available Fai rivers impacted by the Project. The programme will consist of hydrographic data. species and habitat inventories and monitoring of fish migrations and fish productivity. The modifications of the morphology of the Responsibility: The HC will be responsible for the construction Nam Theun downstream of the Nakai Dam to the confluence with of facilities for prevention of increased flooding at Mahaxai on the the Nam Phao will be reviewed at that time. Xe Bang Fai. NTPC will be responsible for the study and the monitoring of Responsibility: The EMO will be responsible for monitoring the activities noted above, as well as operating the Project facility. Project impacts on fish, including fisheries and migration, in the NTPC's development and design costs will fund the monitor- upstream and downstream rivers and reservoir, before and aer ing during Pre-construction and Construction Phases. Failure to the impoundment of the reservoir and for undertaking Nam respond appropriately is covered in the CA under the provisions Theun riparian flow assessments, modifying habitats and for the for a breach or failure to implement any of the Environmental and implementation of the adaptive management programme in the Social Objectives (Clause 30). downstream Nam Theun. The WMPA will take over responsibility for undertaking species EMP Degradation of the Xe Bang Fai River Channel and habitat monitoring in the NPAand Corridors from NTPC one Objective: Mitigate the potential impact from scouring at the yearaerCOD.Theywillalsobeamemberofthecommieeadvis- confluence of the Xe Bang Fai and the Downstream Channel, and ingtheadaptivemanagementprogrammeinthedownstreamNam detect any increase from the natural rate of erosion of the banks of Theun area. In addition, WMPAwill be responsible for incorpora- the Xe Bang Fai below the confluence of the Downstream Channel tion of patrolling, fishing restrictions and other related measures so that remedial works can be undertaken. as part of their planned activities under SEMFOP. Actions: The confluence will be designed, constructed and oper- 2 - Terrestrial animals in the inundation area ated so as to minimise scouring. The confluence of the Down- Aprogramme for mammal species (excluding the Asian Elephant) stream Channel with the Xe Bang Fai will be lined with rip-rap to found in the area to be inundated will be implemented. It will con- prevent scouring of the river bank and direct the discharge to the sist of (i) pre-impoundment species and habitat inventories with main channel of the river. the objective to collect information on distribution and movements During operation, the situation will be monitored and any scour- on the Nakai Plateau, and interactions between species, (ii) devel- ing in the area of the confluence which would risk its structural opment of a post-impoundment species management programme, Management of Impacts 193 EAMP Main Text (iii) implementation of this programme from the beginning of the 5 ­ Wetland conversion and formation. construction phase, including post-impoundment monitoring of Aprogramme for fish, birds, reptiles and mammals species associ- a number of species to determine how the reservoir has affected ated with the swamps and rivers currently located in the area to be wildlife populations. inundated will be implemented. It will consist of (i) pre-impound- Responsibility: The EMO will be responsible for assessing project ment species and habitat inventories, (ii) development of a post- impacts on terrestrial animals before and aer the impoundment impoundment species management programme, including the of the reservoir. The WMPA will take over the post-impound- SpecialConservationAreas,(iii)implementationoftheprogramme ment species management plan for the NPA and Corridors one from the beginning of the construction phase. The programme will year aer COD. In terms of emergency response and enforcement have a dedicated component for the White-winged duck if its pres- (including animal rescue, human-animal conflict and enforcement ence is confirmed during the initial surveys. of hunting rules) NTPC along with local authorities will establish Responsibility: The EMO will be responsible for assessing project an emergency response team and undertake a public awareness impacts on animals pre and post impoundment. The EMO will programme in conjunction with district and provincial authorities. coordinate with the WMPA to develop plans for post impound- NTPC will work with and train district and provincial authori- ment management of wetland species and fish spawning grounds ties, allowing them to take over the role aer COD. The district in Special Conservation Areas. The WMPAwill take over the post- and provincial authorities will work with NTPC in the emergency impoundment species management plan for the NPA and Cor- response and enforcement team (for conflict situations and animal ridors, and the Special Conservation Areas one year aer COD. rescue for elephants and other wildlife) up until aer COD when WMPA will be responsible for patrolling the Special Conservation they will take sole responsibility for this programme. Areas of the Reservoir pre and post impoundment, and for imple- menting their licensing and permiing programme, some of which 3 - Asian Elephant programme have conservation implications, in the area of the reservoir outside The objectives of the elephant programme will be (i) to develop of the Special Conservation Areas. and implement a management plan addressing the seasonal move- Funding Support for the Implementing Agencies in the ments of elephants and their habitat requirements, (ii) to manage Pre-Operating Phase the elephant population affected by the Project, (iii) to help prevent any increase in human-elephant conflicts. The Environmental Management Plan incorporates measures to support and strengthen the GOL organizations that will be During the Construction Phase, NTPC will develop and imple- involved in the implementation and monitoring of the Project. ment a survey and management programme to determine the Emphasis will be placed on training and skill development in core current population of Asian elephants on the Nakai Plateau. The environment and natural resource protection disciplines as well programme will also endeavour to determine seasonal move- as acquisition, development and training of relevant GOL officials ments of elephants on the Nakai Plateau. The programme will in data collection, analysis and management information systems develop an understanding of the ecological role and importance of procedures. elephant habitat use, including mineral licks. Various passive and A: EMU Technical Assistance Programme active crop protection methods will be tested and the successful ones implemented to help prevent human-elephants conflicts. The Objective: The objective of the technical assistance programme elephant management programme will be developed prior to the will be capacity building, including technical support, equipment initial filling of the reservoir. and financial resources for strengthening the EMU (through STEA, the Hydropower office of the Department of Electricity, and pro- Responsibility: The EMO will be responsible for contracting an vincial and district level staff). The technical assistance will enable elephant specialist and developing an effective management pro- the EMU to fulfill their obligations. The physical and technical gramme for the elephant herds on the Nakai Plateau. capacity of the EMU will be developed in stages. The technical 4 ­ Development of a transitional strategy for reservoir assistance will facilitate adequate on-the-job training and technol- impoundment. ogy transfer, enabling the EMU staff to undertake their monitor- ing activities during the Construction and Operation Phases. The The objective of this strategy will be to minimize impacts on ani- TechnicalAssistance Programme will be for a period of three years mal populations of impoundment of the Nakai Reservoir, espe- commencingatthestartofthePreliminaryConstructionPhaseand cially for animals stranded on islands, and which could become ending with the Construction Phase. The technical assistance pro- vulnerable to hunting and habitat loss. gramme includes 12 person-months of international consultants NTPC will appoint a wildlife specialist to undertake an analysis and 100 person-months of Lao consultant and counterpart input. The Technical Assistance Project will have the following overall EMP of potential threats to animal populations during impoundment. The results of the study will be used to develop a plan to minimise aims: impacts on animal populations during impoundment of the res- · To help the EMU to implement the core GOL obligations with ervoir and during the operation phase, and to deal with wildlife respect to the Environmental Measures, including the continu- emergency responses. ous review of the HCCEMMP; Responsibility:TheEMOisresponsiblefordevelopingandimple- · To help the EMU to monitor all NTPC obligations with respect menting a strategy for mitigation of impacts on terrestrial animals to the environmental measures, including monitoring of the work to be undertaken by or on behalf of NTPC; during impoundment and operation and training WMPAand local · To provide on-the-job training to officials of the EMU in order authorities in its implementation ensuring they can take over the to build technical expertise in the environmental and social programme one year aer COD. In terms of emergency response aspects of hydropower projects; and enforcement (including animal rescue, human-animal conflict · To assist the EMU to coordinate its work with other govern- and enforcement of hunting rules) NTPC along with local authori- ment authorities and non-government agencies concerned ties will establish an emergency with the Environmental Objectives; 194 Management of Impacts EAMP Main Text · To instruct central and provincial EMU officials in the proper Responsibility: NTPC will be responsible for the implementation techniques of Project inspection, monitoring, use of field moni- of the programme. $5 million will be made available to undertake toring equipment, data analysis and reporting. the compensatory forestry work ($4.2 million plus $0.8 million The total Technical Assistance Programme budget is estimated at contingency). If necessary, GOL will provide the required land for US$ 768,000. compensatory forestry activities at no cost to the Project. B: Contribution to EMU Operational Budget Mitigation Measures to be Implemented by the Formation of the EMU is a responsibility of GOL, which will be Head Contractor supported by NTPC for coverage of meetings, venues and minor Annex L contains the HCC provisions that relate to the construc- technical assistance on an as-needed basis. The budget estimate is tion phase of the Project. These provisions bind the HC and Con- US$ 50,000. struction Contractors to implement, monitor and review environ- C: EMU Capacity Building at the Local Level mental mitigation measures related to construction activities. The duties of the EMU will involve capacity building at the local Erosion and Sediment Control level as part of the overall scope of the Technical Assistance Pro- gramme. The Technical Assistance Programme approach at the Objective: Minimise erosion and sedimentation from disturbed local level might focus on visual and educational materials, as well areas at construction sites. as utilisation of the village meeting concept, to explain and resolve Actions: The HCC will include specifications for erosion and sedi- issues. There is a separate budget to cover local costs for venues, ment control for construction areas. Erosion and sediment control educational materials and language training. NTPC will provide a measures will be carried out according to a Erosion and Sediment budget of US$ 150,000 for these purposes. Control Plan that uses aerial photography, site surveys and con- struction plans to plan the location and type of controls to be used. D: EMU Training: The Erosion and Sediment Control Plan will be part of a Site Spe- In addition to the on-the-job training that will be provided as part cific Environmental Plan (SSEP) for each site, which will ensure of the Technical Assistance Programme, there is provision for a that controls are well-planned and in correct locations. An SSEP short-term overseas training course for the staff of EMU, as part must be prepared for each site prior to construction at that site. A of the institutional strengthening programme. The training pro- monitoring programme will be established to ensure that erosion gramme will build EMU technical and managerial skills in envi- and sedimentation control measures are in place. The monitoring ronmental assessment of hydropower and water resource projects. programme will include water quality monitoring, which is dis- Trainees selected will be members of the EMU from both the man- cussed below. agement and technical/field operation wings. Responsibility: The responsibility for implementing these actions at each site will be the HC and Construction Contractors. The HC Control of Synthetic Chemical Use for Pest Management & is responsible for determining the type and locations of controls. Other Purposes The HC will also be responsible for supervising each construction Objective: Avoid and minimise potential impacts associated with area to ensure the above activities are implemented. use, storage and disposal of synthetic chemicals such as pesticides, The EMO will ensure that erosion and sediment control specifica- herbicides, fertilisers, or other agricultural chemicals. tions incorporated into the HCC are adequate and fulfill the obli- Actions: NTPC will ensure that all synthetic chemical use will be gations of this EAMP. The EMO will also be responsible for ensur- conducted in accordance with the World Bank Safeguard Policy ing compliance of the HC and construction contractors with these OP 4.09, Pest Management. In the Reselement Area, an agricul- specifications. tural capacity building and awareness programme will be con- Spoil Disposal ducted. This will include long term trials, training and capacity building for technical support staff at various levels including gov- Objective: Minimise impact of disposal of spoil from excavation ernment employees. The plan will promote the use of alternatives activities. to chemicals, and will include a Pest Management Plan. Any syn- Actions: The HC will undertake consultations and studies at least thetic chemicals used must conform to the WHO's Classification six months prior to commencement of construction at each area to of Pesticides. This activity will affect both the Construction and determine the locations of the various spoil disposal areas. This Operating Phases of the Project. will include a landuse impact assessment, community consulta- Responsibility: NTPC will be responsible for implementation of tion and determination if those areas might affect flooding in the appropriate environmental plan for use of chemicals in the the adjacent areas. Determination of the effects on flooding will EMP operation of the transmission lines and for reselement activities. include evaluation of historical land use, frequency of inundation, reduction in flood storage volume and significance of impact. Compensatory Forestry Programme The HCC will include specifications for control of erosion from Objective: Compensate for the loss of 28,000 ha as a consequence the spoil disposal areas that will be incorporated into construction of the Project. contracts. When a spoil disposal area is closed, the construction Actions: The Project will restore a similar area of currently contractors will be required to stabilise the spoil disposal area with degraded forest, under a compensatory forestry programme, that grass, vegetation and permanent drainage. will target a combination of the following areas: (i) the degraded A report on the environmental studies and consultations will be forests within the NNT-NBCA; (ii) the area reserved for the sus- prepared for each spoil disposal site, based on the HCC Spoil Dis- tainable forestry component of the reselement action plan; (iii) posal Management Plan. degraded forests on the Nakai Plateau that will not be affected Responsibility: The HC will be responsible for the pre-construc- by the inundation, and (iv), in case these areas are not sufficient, tion studies and consultations. The HC and construction contrac- degraded forests outside of the area affected by the Project could tors, in consultation with NTPC, will select the spoil disposal be considered. areas. Management of Impacts 195 EAMP Main Text Table 6.3: Wildlife programme schedule TIMELINE `05 `06 `07 `08 `09 Salvage Logging Programme Reservoir Impoundment Fish impacts in Upstream and Downstream Rivers Species and habitat inventory (NT, XBF) Monitoring of fish productivity Fish migration studies in Nam Theun and NPA, and XBF Nam Theun habitat and flow studies Modification of downstream NT habitat, if appropriate Implementation of flow adaptive management programme and related activities Incorporating river protection into the management of NNT and Corridors Impacts to Terrestrial Animals in Inundation Area Programme for mammal species (list of species to be confirmed after completion of pre-impoundment survey). Pre-impoundment species and habitat inventory, distribu- tion and movement on the entire NP. Post-impoundment species and habitat inventory, distribu- tion and movement (non-inundated part of the NP). Development of a post-impoundment species manage- ment programme Implementation of a post impoundment species manage- ment programme Asian Elephant Programme Pre-impoundment inventory and survey of habitats, distri- bution, movements. Implementation of a pre-impoundment elephant manage- ment programme Post-impoundment monitoring of movements and distribu- tion Training of local authorities in conflict response and emergency response Establishment and implementation of an elephant conflict response team Development of a transitional strategy for reservoir impoundment Implementation of a reservoir impoundment elephant management programme Development of a post impoundment elephant strategy Implementation of post impoundment elephant pro- gramme Transitional Strategy for Reservoir Impoundment Development of a strategy/measures targeting wildlife during salvage logging of the Nakai Reservoir Implementation of measures during salvage logging Development of a transitional strategy for reservoir impoundment Implementation of transitional strategy for reservoir impoundment Training of local authorities in wildlife emergency response Establishment and implementation of an emergency response team Public awareness programme Impacts due to reservoir formation including wetland conversion and formation Programme for wetland species (including fish, birds, reptiles and mammals) EMP Pre impoundment species and habitat inventory, distribu- tion and population Development of strategy for species and habitat manage- ment after impoundment Implementation of habitat and species management programme Implementation of biodiversity aspects of reservoir man- agement plan Patrolling of special conservation areas Post impoundment monitoring of populations and distribu- tion Post-impoundment reservoir fish productivity and species monitoring Note: brown: NTPC responsibility; light brown: GoL salvage logging team responsibility; blue: WMPA responsibility (including management of reservoir, dark blue); light blue: District and provincial authority responsibility 196 Management of Impacts EAMP Main Text `09 `10 `11 `12 `13 `14 `15 Commercial Operations EMP Note: brown: NTPC responsibility; light brown: GoL salvage logging team responsibility; blue: WMPA responsibility (including management of reservoir, dark blue); light blue: District and provincial authority responsibility Management of Impacts 197 EAMP Main Text The EMO will conduct a monitoring programme to ensure that approved and monitored by the EMO. The Construction Contrac- the spoil is placed according to plan and in the appropriate areas, tors will be responsible for implementation of the plan. evaluate the potential for failure of the slopes, and monitor the effectiveness of erosion control at each site. Much of this effort will Emergency Plan for Hazardous Materials be incorporated into the water quality monitoring programme dis- Objective: Minimise or prevent impact in the event of spills or cussed below. accidental releases of hazardous materials. Quarries Actions: Preparation of an Emergency Plan for all hazardous Objective: Minimise impacts of quarrying activities. materials used or stored on site. The emergency plan will cover planning, response and training measures for various emergency Actions:Twoquarrieshavebeenidentifiedforacquiringaggregate and additional areas have been identified for acquiring sand and scenarios. Health and Safety Plans prepared by each Construction laterite necessary for construction. Environmental assessments of Contractor will cover other emergency situations. the quarry and borrow sites will be undertaken six months prior Responsibility: The HC will be responsible for the preparation to quarry operation. The assessments will be reviewed and require of the Emergency Plan, which will be approved and monitored approval by STEA. Mitigation measures and procedures for clo- by the EMO. The Construction Contractors will be responsible for sure of the quarries will be included in the assessments. The envi- implementation of the plan. ronmental assessments will incorporate requirements contained in the HC's Quarry Management Plan, from the HCC, and will be Air Quality submied to EMO and GOL for review and approval. Specifica- Objective: Minimise emissions from vehicles and equipment used tions for the use of quarries and borrow areas will be incorporated for construction activities, and minimise fugitive dust from con- into the construction contracts. struction areas and unpaved roads within construction areas. Responsibility: The HC will be responsible for management of the Actions: Preparation and implementation of an Emissions and quarries and borrow areas in accordance with the provisions of Dust Control Plan. This Plan will be prepared by the HC for imple- the environmental assessments. The EMO will review the assess- mentation by the construction contractors. The Plan will contain ment and ensure that the specifications are incorporated into the measures such as regular spraying of unpaved roads used by con- construction contracts. The EMO will develop a monitoring pro- struction vehicles, regular maintenance of vehicles and equipment, gramme to ensure that quarry operations are in accordance with the HCC and are in compliance with the respective environmental and limiting burning of waste. assessment. Responsibility: The HC will be responsible for the preparation of the Emissions and Dust Control Plan, which will be approved Water Quality Monitoring (HC) and monitored by the EMO. The Construction Contractors will be Objective: Monitor the effects of surface water runoff and waste- responsible for implementation of the plan. The HC will develop water discharge from areas disturbed by all construction related an air quality monitoring programme to ensure that specifications activities on water quality. within the HCC are respected. Actions:Themonitoringprogramwillincludemonitoringforboth Noise Management point sources and non-point sources of pollution. This includes (i) stormwater discharge from all construction sites (in-stream and Objective: Minimise the amount of noise generated at construc- point of discharge monitoring); (ii) runoff from construction work tion sites. camps;(iii)runofffromwastedisposalareasandconstructionwork Actions: Preparation of a Noise Control Plan. areas; (iv) effluent from crushing plant. A Water Quality Monitor- ing Plan will be prepared as a component of the HCCEMMP. Responsibility: The HC will be responsible for the preparation of the Noise Control Plan, which will be approved and monitored Responsibility: The HC will be responsible for the preparation of by the EMO. The Construction Contractors will be responsible for the Water Quality Monitoring Plan, which will be approved and implementation of the plan. Monitoring of noise in the construc- monitored by the EMO. The Construction Contractors will be tion areas will be the responsibility of the HC. responsible for implementation of the plan. Physical Cultural Resources Chemical Waste & Control of Spills Objective: Minimise the potential for impacts associated with han- Objective:Avoidorminimiseimpacttophysicalculturalresources dling, storage, use and disposal of chemicals on site during con- affected by the Project construction, inundation and operation. struction. This includes items having archaeological, paleontological, histori- cal, religious, sacred or unique natural values. EMP Actions: Materials and chemicals that will be used during con- struction includes explosives, fuel and oils, paints, solvents, acids, Actions: The HC will prepare a Physical Cultural Resources Plan. coagulants, bentonite and concrete additives. A Chemical Waste In addition to outlining measures to protect identified physical and Spillage Management Plan will be prepared, which will cultural resources, the plan will also include a `Chance Find Proce- include implementation and monitoring of the use of chemicals dure' that outlines actions to be taken in the event of a previously and chemical waste. All pesticide use will be conducted in accord- unknown resource being found. ance with the World Bank Safeguard Policy OP 4.09, Pest Man- Responsibility: The HC will be responsible for the preparation agement. Activities to be conducted by the HC will be control- of the Physical Cultural Resources Plan, which will be approved led to prevent or minimise impacts from synthetic chemical use. and monitored by the EMO. The Construction Contractors will be The Chemical Waste and Spillage Management Plan will describe responsibleforimplementationoftheplan.TheHCwillberespon- which chemicals can and cannot be used during construction. sible for notifying the EMO of any previously unknown physical Responsibility: The HC will be responsible for the preparation of cultural resources uncovered during the preparation of sites for the Chemical Waste and Spillage Management Plan, which will be construction activities, using the `Chance Find Procedure'. 198 Management of Impacts EAMP Main Text Vegetation Clearing (HC) Environmental Training Objective: Minimise vegetation clearing for construction activities Objective: Implementation of a training program for construction and control erosion and sedimentation from disturbed sites. workers in relation to environmental issues, to raise the awareness Actions: The HCC will include specifications for the removal of and enhance the skills of the construction workforce. vegetation from the construction areas and management of runoff Actions: Training is to be carried out in three main areas: from disturbed areas. All land and vegetation clearing activities will be carried out according to a Vegetation Clearing Plan that · General environmental awareness, including rules and regula- uses aerial photography, site vegetation surveys and construction tions to be followed on construction sites and camps; plans to mark out areas to be cleared. The Vegetation Clearing · General health and safety awareness, including an AIDS/HIV Plan will be part of a Site Specific Environmental Plan (SSEP) for and STD awareness program; and each site, which will ensure that vegetation disturbance is planned · Job-specific training for workers with responsibility for high- and minimised. An SSEP must be prepared for each site prior to risk activities that could have adverse impacts on the environ- construction at that site. A monitoring programme will be estab- ment or humans. lished to ensure that the clearing of vegetation does not exceed the Further information on the program, trainers, content of courses area shown in the Vegetation Clearing Plan, and that erosion and and participants will be provided in an Environmental Training sedimentation control measures are in place. The monitoring pro- for Construction Workers Plan. gramme will include water quality monitoring. At the end of the Responsibility: The HC will be responsible for the preparation of construction period, disturbed areas will be inspected to ensure an Environmental Training for Construction Workers Plan, which that each site has been re-graded to conform to the natural topog- will be approved and monitored by the EMO. The Construction raphy, and that appropriate grasses and shrubs have been planted Contractors will be responsible for implementation of the plan. to start the re-vegetation process. The construction contractors will be responsible for the grading and stabilisation of construction Traffic and Access areas before they are allowed to vacate the construction areas. Objective: Implementation of measures to manage traffic and Responsibility: The responsibility for implementing these actions access on the construction site during the construction works. at each site will be the HC and Construction Contractors. The HC Actions: Tasks relate to vehicle fleet maintenance, handling traf- is responsible for determining the locations of areas that will be fic movements on internal and public roads, signage, parking and disturbed during the construction period. The HC will also be access. responsible for supervising each construction area to ensure the above activities are implemented. Responsibility: The HC will be responsible for the preparation of a Traffic and Access Management Plan, which will be approved The EMO will ensure that vegetation removal specifications incor- and monitored by the EMO. The Construction Contractors will be poratedintotheHCCareadequateandfulfilltheobligationsofthis responsible for implementation of the plan. EAMP. The EMO will also be responsible for ensuring compliance of the HC and construction contractors with these specifications. Explosive Ordnance Survey and Disposal Additionally, the EMO will inspect construction areas at the end of the Construction Phase to ensure that the areas are stabilised and Objective: Implementation of measures to identify and dispose of revegetated before the construction contractor can vacate the area. unexploded ordnance (UXO) that may occur at construction sites. Actions: Preliminary assessment has shown that there is a high Waste Management probabilityofUXOcontaminationbeingpresenton-site.Appropri- Objective: Proper management of solid and liquid waste gener- ately qualified and experienced specialists will be used to carry out ated during construction. UXO survey and disposal activities, prior to the commencement of Actions: A Waste Management Plan will be developed by the HC. any construction works. The UXO specialists will be required to Specifications for waste management will be incorporated into the have suitably qualified personnel and suitable systems for quality HCC. Construction contractors will be responsible for day-to-day control and occupational health and safety in place. Risks to the management of waste, storage areas and disposal areas. surrounding local population will be reduced through the imple- mentation of an UXO Awareness Program. The larger construction camps will be equipped with wastewater treatment facilities to treat all sewage and domestic wastewater. Responsibility: The HC will be responsible for the preparation of Sewage from some other sites will be trucked to these facilities for an Unexploded Ordnance Survey and Disposal Plan, which will be treatment. Smaller or temporary camps and work sites will use approved and monitored by the EMO. The Construction Contrac- EMP pit latrine toilets. To ensure that wastewater treatment is effective, tors will be responsible for implementation of the plan. the HC is required to implement a water quality monitoring pro- Construction Work Camps gramme. This will be defined further in the Water Quality Moni- toring Plan to be prepared by the HC which is described above. Objective: Mitigate potential impacts of establishing and operat- Specifications for the wastewater treatment facilities will be incor- ing construction camps. porated into the HCC. Actions: Issues at construction camps include drainage and ero- Responsibility: The HC and Construction Contractors will be sion control from the disturbed areas; health issues; and spontane- responsible for the preparation of a Waste Management Plan, ous development of businesses and accommodation not directly which will be approved and monitored by the EMO. The Con- associated with construction activities. These issues will be cov- struction Contractors will be responsible for implementation of ered by the preparation of a Construction Work Camps Plan. the plan. Waste management by the Construction Contractors will Responsibility: The HC will be responsible for developing the be monitored by the HC and EMO and will ensure that waste is Construction Work Camps Plan, and design and construction handled, tracked and disposed as described in the Waste Manage- of work camps. The EMO will be responsible for monitoring to ment Plan. ensure compliance with the plan. Management of Impacts 199 EAMP Main Text Project Staff Health Programme Responsibility: GOL, through the EMU, will be responsible for Objective: To ensure that the health of the construction work force the clearing activities. NTPC will be responsible for providing is maintained. technical assistance in relation to the clearing activities. Actions:NTPCwillensurethatdiseasecontrolmeasuresareimple- Control & Enforcement ­ Access & Hunting mented by the HC at the time the construction camps are built and Objective: Reduce the impact arising from uncontrolled access during the construction period while the camps are inhabited. and hunting on wildlife and habitats of the watershed area, includ- Construction camp siting decisions will be made considering good ing the reselement area. drainage, water supply, sewage disposal and disease transmission potential,especiallymalaria.Essentialcontrolelementssuchasfly- Actions: The control of access and hunting will be an integral part proofing will be incorporated into camp design. Where this cannot of GOL's management of the watershed area. Hunting controls be done, pyrethroid-treated mosquito nets will be made available. shall be introduced and enforced by GOL. This activity will be part An adequately staffed clinic will be sited at the base camp with of operational management of the NBCAand reselement area. subsidiary treatment posts at smaller camps. Responsibility: GOL, through the EMU, will be responsible for these activities in the reselement area. Funding for these activities Responsibility: The HC will be responsible for developing the in the NBCAis included in NTPC's commitment to the administra- Project Staff Health Programme. The EMO will be responsible for tion, planning and operational cost of the WPMA. monitoring to ensure compliance with the plan. Public Education Concerning Environmental Issues Transmission Lines Objective: Instill environmental awareness in the population of Objective: Mitigate the impacts of vegetation and habitat loss, dis- the Nakai Plateau, to reduce exploitative approaches to wildlife turbance from construction, possible soil toxicity from the applica- and habitats. tion of chemicals used in vegetation clearance, and possible health risks associated with electromagnetic fields generated by transmis- Actions: Instituting an education and public awareness pro- sion lines. gramme, including the training of trainers and guards, and regu- lar exposure to educational films, information sessions and school Actions: Forested area will be avoided as much as possible, and tours on and around the Plateau, to promote behavioural change. appropriateloggingtechniqueswillbeemployedwherevegetation This will be a long-term investment with a lag of several years clearing is unavoidable. Use of chemical will be avoided. Electro- in returns in basic behavioural changes. The four main elements magnetic impacts from operation will be minimised by prohibition of the education programme include (i) a quantitative survey of of dwellings and businesses in the transmission line easements. the aitudes of Plateau residents to natural resources and deci- Responsibility: The HC will be responsible for these activi- sion-making processes; (ii) translation of video and print media, ties, which will be covered by Site Specific Environmental Plans preparation of slide and poster materials; (iii) teacher training and (SSEPs), which is a part of the HCCEMMP. NTPC will ensure that Conservation Officer (guard) training workshops on techniques the SSEP for each site adequately covers the environmental impact of outreach and communication; and (iv) acquiring and fiing a mitigation measures and that they are properly implemented. mobile audio-visual nature education unit. GOL also has a responsibility to ensure that no new dwellings or Responsibility: GOL, through the EMU, will be responsible for businesses will be located in the transmission line easements. the activity, with NTPC providing funding. Roads Minimisation of environmental impacts at resettlement sites Objective: Minimise impacts during the construction and upgrad- ing of roads. Objective: Minimise impacts of constructing and establishing the reselement sites. Actions: New road alignments will be minimised in favour of upgrading existing roads and, for new roads, the alignment will Actions: All subplans of the HCCEMMP will be applicable during endeavour to minimise damage to vegetation or other sensitive the establishment of the reselement sites. environments. Responsibility: GOL, through the EMU, will be responsible for Responsibility: The HC will be responsible for these activi- ensuring compliance of construction activities with these specifi- ties, which will be covered by Site Specific Environmental Plans cations. (SSEPs). NTPC will ensure that the SSEP for each site adequately Restriction of Shifting Cultivation covers the environmental impact mitigation measures and that they are properly implemented. Objective:Avoidorminimisepotentialshiingcultivationimpacts that reduce habitat diversity in the Dividing Hills and escarpment EMP Mitigation Measures to be Implemented by GOL forests. This programme aims to reduce fire damage, erosion, and Organisations downstream sedimentation, as well as illegal forestry activities extending into the critical habitats of the Dividing Hills. Water Quality Improvements by Reduction of Biomass in Actions: Shiing cultivation will be restricted in the Reselement the Nakai Reservoir Area Area and alternative agricultural and livelihood activities estab- lished to replace crops and income previously derived from it. Objectives: Improve water quality in the reservoir by reduction of Livelihood activities will be supported under both the RAP and residual biomass levels. the SEMFOP and provide alternatives to shiing cultivation. Actions: NTPC will provide technical assistance in determining Responsibility: These activities will be part of the operational the means and economics of maximising the removal of biomass responsibilities of the Reselement Management Unit (RMU) as from the Nakai Reservoir area, including poorly formed and small they implement the RAP. The WMPA will control shiing agricul- diameter logs. NTPC will also promote firewood collection from ture within the NNT NBCAand corridor areas as part of its stated the inundation area during the construction phase. objective to facilitate improved livelihoods for inhabitants of the 200 Management of Impacts EAMP Main Text Nam Theun 2 Watershed Area by focusing on poverty reduction · Any breach of the construction contractors'obligations for mit- through environmentally sustainable development. The Social igation and compensation measures should be immediately Development Plan (SDP) gives further details on the organisation, remedied. function and planned activities of the RMU. The CA contains all of the Project mitigation and compensation Transmission Lines measures. These are set out in Parts 1, 2 and 3 of Schedule 4 and constitute the Environmental and Social Objectives. Part 1 deals Objective: To mitigate the impacts of possible health risks associ- with the social and reselement objectives of the Project outside ated with electromagnetic fields generated by transmission lines. the Nam Theun 2 Watershed Area to be implemented by GOL Actions: Electromagnetic impacts from operation will be mini- and NTPC, and to be funded by NTPC. Part 2 deals with the mised by prohibition of dwellings and businesses in the transmis- environmental objectives of the Project outside the Nam Theun 2 sion line easements. Watershed Area to be implemented by NTPC and GOL, and to be funded by NTPC. Part 3 deals with the social and environmental Responsibility: GOL will ensure that no new dwellings or busi- objectives of the Project in the Nam Theun 2 Watershed Area to be nesses will be located in the transmission line easements during implemented by GOL, and to be funded by NTPC. the Operating State of the Project. Funding & Responsibilities for Implementing the Implementation of Mitigation Measures Environmental Management Plan Provisions of the Concession Agreement The implementation responsibilities and cost of the mitigation of environmental impacts, and the institutional support to GOL The CA acknowledges that as a result of GOL granting the con- agencies and the WMPA, which will be funded by NTPC, are sum- cession to NTPC and the subsequent construction and operation marised in Tables 6.4 and 6.5 of the Project, there will be significant and adverse environmental Environmental Performance Guarantee and social impacts. The CA also acknowledges that certain Envi- ronmental and Social Plans have been developed and agreed to by For the purposes of establishing guarantees for implementation of GOL and NTPC for the purpose of identifying Project impacts in environmental mitigation measures, a performance guarantee will the form of the EAMP, the SDP, and the SEMFOP. be posted by NTPC. The initiatives and measures identified in the EAMP, the RAP, and the SEMFOP will be termed collectively as As specified in the CA, and where applicable, GOL and NTPC "Environmental and Social Objectives". organisations will be responsible for addressing, alleviating and NTPC has agreed to comply with, implement alone or jointly with remedying such impacts. The CAoutlines the environmental obli- another party, and bear the cost of the Environmental and Social gations of both organisations, including: Objectives as identified in the CA. Insurance that the mitigation · The social and reselement objectives within the Nam Theun measures are implemented and are successful will be the respon- 2 Watershed Area. The exception to this is that the Watershed sibility of NTPC. Management and Protection Authority of GOL is responsible The insurance includes provisions for assuring that the environ- for the management of the Nakai Nam Theun National Pro- mental mitigation measures are implemented according to the tected Area and corridor areas. These activities will be funded plans set forth in the design of the Project, and in the plans for the by NTPC; management of the Nakai Reservoir, the Power Station, the regu- · The environmental objectives within the Nam Theun 2 Water- lating pond and Downstream Channel and the impacts to the Xe shed Area, with the exception of the Nakai Nam Theun Bang Fai. NTPC's obligations to comply with the Environmental National Protected Area. These activities will also be funded and Social Objectives will be limited either by cost to a Budgeted by NTPC; and Limit, as set out in the CA, or will not be limited by cost. The Envi- · The fact that environmental components of the Project within ronmentalandSocialObjectives,whichareactivitiesorobligations the Nam Theun 2 Watershed Area include key environmental of NTPC expressed to be limited by cost, are referred to as "Lim- obligations that will be the responsibility of NTPC. In these ited by Cost" Environmental and Social Objectives. The remain- cases, the CA provides for approval of amendments to the CA der, whether or not there is an amount specified alongside that by the International Panel of Experts. Environmental and Social Objective, are referred to as "Limited by Scope" Environmental and Social Objectives. Based on these conditions, NTPC is required to: · Implement the environmental mitigation and compensation Contingencies measures identified as being the responsibility of NTPC; Substantial contingency funds will be established by NTPC to EMP · Ensure that the Environmental Monitoring and Management guarantee sufficient funding for the appropriate implementation Plan (EMMP) is prepared and implemented as required by the of the Environmental and Social Objectives. In particular, con- CA; and tingency allowances have been made for SEMFOP Activities, the · Ensure that the EMMP agrees with the conditions of the CA. Reselement Programme, the Wildlife Monitoring Programme, In addition, NTPC is required to ensure that the construction con- and the EMU Technical Assistance Programme. tractor implements measures that will avoid, compensate, allevi- Although contingency budgets have been allocated to many of the ate, mitigate or remedy environmental and social impacts to the mitigation measures, the first source of additional funding will be extent possible under the agreement. from the Environmental Guarantee Insurance. This includes fund- Under the CA, it is required that: ing that may be required for an adaptive management approach to some of the mitigation measures. · NTPC meets its own obligations under the Construction Con- tracts; Limited by Cost Objectives · The construction contractors implement all of the required For Limited by Cost Objectives, the financial liability of the Com- environmental mitigation and compensation measures; and pany will be limited to the indicated budget amount. In the event Implementation of Mitigation Measures 201 EAMP Main Text Table 6.4: Mitigation Budget Measures HC GOL WMPA NTPC Biophysical impacts 150,000 1,470,500 Supporting implementing institutions 1,108,000 Independent monitoring 345,000 Differential construction cost for implementing envi- 34,500,000 ronmental activities Funding of the WMPA 31,500,000 Sub-totals 34,500,000 1,603,000 31,500,000 1,470,500 Grand total 69,073,500 Note: NTPC Budget does not include NTPC's operating cost and some Fixed Scope items. of a breach or failure to implement an Objective where the budg- ishable by the issue of an additional Unanticipated Project Impacts eted amount is insufficient for a proper remedy, there is a provi- Leer of Credit, for US$ 2,500,000 (as adjusted to take into account sion in the CAfor NTPC to meet the extra cost, provided that when inflation) and for any unused amount under the first Unantici- aggregated with the overrun cost of all other Limited by Cost Envi- pated Project Impacts Leer of Credit. ronmental and Social Objectives, it would not exceed the aggre- gate Overrun Allowance of US$ 2,500,000 (as adjusted to take into Monitoring account inflation). Monitoring will determine during the concession period (pre- Similarly, NTPC will be obliged, where the budgeted amount of construction, construction and operation) whether the mitigation any Limited by Cost Objective is not used by NTPC in its achieve- measures undertaken by NTPC and other agencies responsible for ment of the Limited by Cost Environmental and Social Objectives implementation of activities are achieving their objectives. Internal to which it relates, to allocate the resulting Under-run Amount and external monitoring of the Environmental Measures will be towards the cost of implementing another Limited by Cost Envi- undertaken by the parties in accordance with the CA Schedule 4, ronmental and Social Objective. In addition, NTPC must give Part2,Clause6.Externalmonitoringwillbeundertakenduringthe regard to any requested allocation reasonably made by GOL. Construction Phase and for the first three years of the Operating Limited by Scope Objectives Phase. The monitoring will be extended if either NTPC, or GOL or the Panel of Experts recommends that further external monitoring If the cost to NTPC of implementing an Environmental and Social is required because the Project impacts are not fully mitigated. Objective is not limited by a CA budgeted limit (i.e. it is Limited by Scope) then NTPC will be obliged to fund the implementa- Although the monitoring programmes have yet to be designed for tion of that Environmental and Social Objective to its completion. the construction period, their basic outline will incorporate the fol- This must occur, notwithstanding the fact that the actual cost to lowing sections: i) Objectives and purposes; ii) Methods for obtain- NTPC of that implementation may exceed the internally budgeted ing the data relative to the associated impacts; iii) Parameters to be amount. measured; iv) Frequency of sample collection; v) Locations of sam- plecollection;vi)Analyticalproceduresanddatapresentation;and Non-compliance Procedures vii) Reporting protocol. The sample collection and analysis meth- The obligations of NTPC in relation to its Environmental and ods will conform to standard collection procedures. Frequency of SocialObjectivesaretobesecuredinpartbyanEnvironmentaland data collection will depend upon the parameters being monitored. Social Objectives Leer of Credit for US$ 2,500,000. This amount is Along with the frequency of sample collection, the locations where replenishable by the issue of up to two additional Environmental samples or observations will be made will determine whether or and Social Leers of Credit, of not more than US$ 2,500,000 each, not it is possible to determine if the mitigation measures are effec- (as adjusted to take into account inflation) and for any unused tive. amounts under the first and second Environmental and Social The analytical procedures and data presentation for evaluating the Objectives Leers of Credit. results of the monitoring programmes will determine if the miti- gation measures are effective. This will require baseline informa- Unanticipated Project Impacts tion for comparison. Frequency of reporting will depend on the While every effort is made in the major assessment and manage- parameters being followed, but immediate reporting to NTPC ment plans to encompass all potential impacts and include appro- will be required if the monitoring programmes identify problems EMP priate responses, the CAacknowledges that Unanticipated Project which need to be rectified urgently. Results of the monitoring pro- Impacts may occur, being unintended and unforeseen impacts. grammes will indicate whether or not the mitigation programme The CAaccounts for the need to remedy any such impacts through is effective. If problems arise with a particular mitigation measure, the "Unanticipated Project Impacts" provisions. If such impacts the construction contractors will be asked to take corrective actions occur,NTPCwillbeobligedtoremedythoseUnanticipatedProject before continuing with the construction. Impacts, or permit GOL to do so under the funding of NTPC, sub- ject to NTPC's overall aggregate limit of liability for the uninsured Internal Monitoring by the EMO costs of those Unanticipated Project Impacts not exceeding the The EMO will: amount of US$ 10,000,000 (as adjusted to take into account infla- · Manage and implement the overall Monitoring Programme tion). and supervise the monitoring done by other organisations; The obligations of NTPC in relation to the Unanticipated Project · Monitor and inspect construction sites to assess the perform- Impacts are to be secured in part by an Unanticipated Project ance and compliance of the HC and Construction Contractors Impacts Leer of Credit, for US$ 2,500,000. This amount is replen- in relation to the HCC; 202 Implementation of Mitigation Measures EAMP Main Text Table 6.5: Implementation responsibilities and cost of mitigation Project Stage Aspect "Budget Responsibilities (USD) Design Construction Operation Fixed Scope or Limited by Cost" Mitigation Measures to be implemented by NTPC Engineering measures and monitoring/maintenance of structures Incl. in HCC, NTPC development & operating cost, EMO scope Aeration of Water in the Downstream Channel & Nam Kathang Downstream Channel In-Stream Degradation Protecting Downstream Channel Fisheries Prevention of Increased Flooding at Mahaxai on the Xe Bang Fai Prevention of degradation of the Xe Bang Fai Channel Management of construction related environmental impacts Incl. in EMO scope for monitoring Hydroelectric Project Infrastructures Resettlement related Infrastructures Water Quality Management & Monitoring Programme 690,000 Wildlife Management and Protection Programme - Fish impacts in upstream and downstream rivers 177000 Terrestrial animals in the inundation area 422000 Asian elephant programme 200000 Transitional strategy for reservoir impoundment 350000 Wetland conversion and formation 421500 Adaptive Management Programmes Part of the wildlife management programmes and EMO scope Riparian release downstream of the Nam Theun Water release to the Nam Kathang Management of water release to the Downstream Channel Wildlife Programme Mitigation Measures to be implemented by the Head Contractor Erosion and Sediment Control Plan Included in HCC, EMO scope for monitoring Spoil Disposal Planning and Management Plan Included in HCC, EMO scope for monitoring Quarry Management Plan Included in HCC, EMO scope for monitoring Water Quality Monitoring Plan (HC) Included in HCC, EMO scope for monitoring Chemical Waste & Spillage Management Plan Included in HCC, EMO scope for monitoring Emergency Plan for Hazardous Materials Included in HCC, EMO scope for monitoring Emission and Dust Control Plan Included in HCC, EMO scope for monitoring Noise Control Plan Included in HCC, EMO scope for monitoring Physical Cultural Resources Plan Incl. in HCC, NTPC dvpt. cost, EMO scope for monitoring Landscaping and revegetation Plan Included in HCC, EMO scope for monitoring Vegetation Clearing Plan (HC) Included in HCC, EMO scope for monitoring Waste Management Plan Included in HCC, EMO scope for monitoring Reservoir impoundment Management Plan Included in HCC, EMO scope for monitoring Environmental Training for Construction Workers Plan Included in HCC, EMO scope for monitoring On-site Traffic and Access Management Plan Included in HCC, EMO scope for monitoring Explosive Ordnance Survey and Disposal Plan Included in HCC, EMO scope for monitoring Construction Work Camps Plan Included in HCC, EMO scope for monitoring Manual of Best Practices in Site Management of Environmental Matters Included in HCC, EMO scope for monitoring EMP Project Staff Health Programme Included in HCC & US$4,500,000, RMO for monitoring Development of individual Site Specific Enviromental Plans (for the 66 construc- Included in HCC, EMO scope for monitoring tion sites, incl. Transmission Lines, Roads, etc) Mitigation Measures to be implemented by GOL Management of the Watershed WMPA, US$31,500,000 Salvage Logging & Reduction of Biomass in the Nakai Reservoir Area 50,000 & EMU TA Budget Control & Enforcement ­ Access & Hunting Incl. in EMU TA budget, WMPA budget Compensatory Forestry Incl. in SEMFOP activities Restriction of Shifting Cultivation Incl. in EMU scope, budget for RAP and WMPA Transmission Lines Incl. in GOL scope for monitoring Funding Support for Implementing Agencies - Pre-Operating Phase EMU Technical Assistance Programme, operational budget, etc. 1,158,000 Independent Monitoring Agency 345,000 Implementation of Mitigation Measures 203 EAMP Main Text · Regularly review the status of the Project impacts; If complaint origin is beyond responsibility of EFI, he will report · Make recommendations to NTPC to rectify any failure to per- immediately to CEC for appropriate action. form its obligations in respect of the Environmental Measures; The EMU, represented at the local level, will also have the ability and to record complaints in a similar way. The EMU will then inform · Report regularly to the EMU. immediately the EMO for appropriate actions, either through the Internal monitoring by the EMU HCC and the CC, or through the adaptive management commit- tees that will handle environmental impacts of the Project. The EMU will: · Monitor the performance by GOL of the Environmental Miti- Adaptive Management gation Measures that constitute GOL obligations; The principles of adaptive management are used frequently in the · Make recommendations to GOLthat it take steps to rectify any scope of work for the protection or mitigation measures discussed failure by GOLto perform its obligations in respect of the Envi- in this EAMP. The use of Environmental Assessments by public ronmental Objectives; policy decision-makers to assess Project impacts has highlighted · Report regularly to GOL, with a copy to NTPC; and the notion that science is rarely able to elucidate a single, satisfy- · Review the activities undertaken by the EMO. ing "bright-line" path to public policy decisions (McConnaha and Independent Monitoring Paquet,1997).Scientistsoenconfrontpolicydecision-makerswith uncertainties, documented opposing viewpoints, and the need for GOL, in consultation with NTPC, will engage an independent further study reflecting the uncertainties of natural systems. Many monitoring agency with relevant qualifications, experience and important resource policy decisions cannot wait for the resolution international standing, to externally monitor and evaluate meas- of scientific uncertainty.Adaptive management has been advanced ures implemented to address the Environmental Measures on an as a means to join science and public policy. annual basis and at other times as required by GOL. This monitor- ing will include the status of the implementation of the obligations Generally, adaptive management of environmental issues involves of GOL and NTPC under the CA, relevant to the Environmental the monitoring and evaluation of environmental performance of Mitigation Measures and also the Project impacts referred to in the a particular programme or activity, and then responding to that CA, during the Construction Phase and for the first three years of evaluation with appropriate changes to the programme or activity. the Operating Phase. This is an iterative process, repeated for as long as it takes for an environmentalsystemtostabiliseaeranimpact.Inthecaseofthis The independent monitoring agency will report to GOLand NTPC project, adaptive management is defined as the acknowledgement on its findings. NTPCandGOLmustcooperatewiththeindepend- that changes may need to be made to the methods used to address ent monitoring agency and provide it with access to all relevant and implement the objectives set forth. The CA, Schedule 4, Part data, documentation, programme activities and sites to facilitate 2, incorporates the philosophy of adaptive management when it the effective monitoring and evaluation. NTPC will be responsible states that changes can be made to the methods used to address forfundingthecostsassociatedwithappointmentoftheindepend- and implement the Environmental Objectives, provided that such ent monitoring agency. However, payment will be made to GOL, changes are acceptable to GOL, NTPC and the Panel of Experts. who will in turn pay the independent monitoring agency. Funding by NTPC for the independent monitoring agency will be limited to In many cases the monitoring and evaluation process will require US$225,000 for the Construction Phase (assuming a Construction additional, and sometimes extensive, survey and primary data Phase of 4.5 years) and US$120,000 for the first three years of the collection, either to establish a baseline or to measure changes. In Operating Phase. GOL will make available to NTPC and to other order to respond to evolving management needs, a contingency interested parties (on request), annual progress reports of the inde- budget may be required ­ especially where responses may require pendent monitoring agency. capital works. In the Project, some substantial contingencies have already been allocated, as discussed above. In cases where a con- Panel of Experts tingency budget has not been allocated, contingencies will take the In addition to the provisions discussed above, the Environmental form of performance commitments wrien into both the CA and and Social Panel of Experts (POE) is mandated to provide inde- the Head Construction Contract, as recommended by the World pendent review of, and guidance on, the treatment of environmen- Commission on Dams (2000). tal and social issues associated with the Project. Amongst other The question of what triggers adaptive management review and duties, the POE will provide reports to NTPC stating whether the how decisions are made to use available but contingent funds for Environmental and Social Objectives and the World Bank Guide- implementing mid-course adjustments, needs to be addressed. lines have been complied with in the amelioration or remediation Logically, an appropriate research, monitoring, and evaluation of Unanticipated Project Impacts. The POE will recommend reme- programme will yield a stream of data whose regular, periodic analysis will reveal ecological insights or clarification of impacts. EMP dial action in the case of considered non-compliance. Further dis- cussion of the role of the POE is found in Annex O. Three of the major applications of the adaptive management approach will be for the riparian release from the Nakai Dam into Environmental grievance procedures the Nam Theun, the management of wildlife populations on the Construction related environmental complaints handling and pos- Nakai Plateau, and the periodic update of the EMMP. sible resolution will be carried out at CC level; fully registered An adaptive management approach to riparian release will information on complaints and resolution will be communicated determine how the total volume released should be managed to to HC Environmental Control Officer (ECO) for further action maintain specified, valued features of the ecosystem (Tharme, in if justified. Complaint register will be opened at each site access prep). The baseline monitoring programme will suggest possible gate, under the responsibility of the access control staff, and will modified hydrological regimes and morphology of the channel for consist in a book with numbered pages where any complainer the river. Predetermined objectives, reflective of the preferred or may register date, name, address and purpose of complaint. CC intended future ecosystem condition, can be used to measure and Environmental Field Inspector (EFI) will be in charge of routine assess the implementation or effectiveness of the nominated ripar- check of registered complaints and to identify resolution solutions. ian release paern. With this information, the management strat- 204 Implementation of Mitigation Measures EAMP Main Text egy of the nominated riparian release waters can then be reviewed Proposed Implementation Arrangements: Implementation and revised, while maintaining the same total volume of water. arrangements for the various programmes are described below. In the case of wildlife management, the basic biological survey They were designed to practically apply the principles of adap- (based upon existing perceptions and experience such as the tive management to the Project, taking advantage of existing insti- key and indicator species for each habitat, as enumerated in this tutions and programmes as much as is possible and taking into EAMP) will begin as soon as the Construction Phase of the Project account the relative utility of analytical inputs and stakeholder commences. This includes the Elephant and White-Winged Duck inputs. Programmes. Wildlife Programme: Other areas where adaptive management will be used are: The Wildlife program will include species and habitat manage- · Management of the regulating pond for flows to Nam Kathang ment programmes covering the major impacts areas (upstream and Xe Bang Fai; and downstream rivers, inundation and plateau area, wetlands · Erosion control in the Xe Bang Fai in terms of temporal flow in Special Conservation Areas). The programme involves sig- management and mitigation measures; nificant monitoring and has the flexibility to take a variety of · Downstream and reservoir water quality; management measures in certain programmes such as the White · Management of the reservoir for multiple uses; winged duck, wetland management and elephant programmes. · ReviewandupdatingtheHCCEMMPonanannualbasis,using It will be implemented through a combination of NTPC, district the results of monitoring and auditing carried out through the authorities, WMPA, GoL entity in charge of salvage logging and year. the RMA. Coordination will be undertaken through the board of In addition to studies relating to riparian releases and wildlife, the WMPA. otherstudiesareeitherongoingorwillbeconductedfortheProject Proactive experimentation: This concept will be mainstreamed as to assist in preventing, mitigating and monitoring potential Project part of the development and implementation of the management impacts. These studies will also, in some cases, facilitate the adap- plans which will outline and test options for achieving manage- tive management approach. ment goals. It will be important to ensure that for relevant man- Aer a year of seasonal studies, an initial conceptual model will agement measures several approaches are tested at once, as the be developed in a series of workshops involving all stakeholders, time period for feedback and reevaluation would be months or but most particularly experts in the topics and local ecosystems. years for many wildlife related issues. The adaptive management Among the products of such an effort will be a prioritised list of will be undertaken by the responsible authorities for these plans data needed, and the most likely candidate data sets needed for with the help of TAprovided through the programme. a continuing monitoring system. These will measure the fewest Monitoring: Monitoring is a major part of the programme and and most telling types of information ­ the variables and rates to can be used to evaluate the effectiveness of programmes. It will which the ecosystem is very sensitive. Those experts involved with be undertaken primarily by NTPC until post COD when it will be programme annual reviews and recommendations should then transferred to various GoL agencies. formalise the programme. In each of the first five years, the list of Reevaluation and experimental design: As part of the manage- monitoring targets will be reviewed and amended. Thus, the adap- ment plans, the monitoring will be used to redesign or refine man- tive management process will accommodate any changes based on agement approaches. As this may necessitate inputs beyond the new information, even if it is outside of the regularly scheduled basic monitoring and planning provided under the individual pro- review process. grammes discretionary funds will be available for more sophisti- Adaptive Management Approach cated analysis of monitoring results or expert opinion on interna- tional practices. Adaptive management is used in cases where the ideal manage- Decision making through multiple stakeholders: It is proposed ment approach is not readily apparent upfront and where there is that decisions on objectives and approaches to adaptive manage- sufficient flexibility to test and optimize different approaches. It ment be done by the respective implementing agencies but include typically involves several elements: (i) Proactive experimentation: consultation with the important stakeholder groups in their deci- The management measures are a proactive way to find effective sion process. approaches to management; (ii) Monitoring: The effectiveness of the management measures are monitored; and, (iii) Reevaluation Riparian Release Downstream of Nakai Dam: and experimental design: The sophistication of this is depend- The riparian flow release and the spills downstream of the dam ent upon the issue, however, in general this involves evaluation will be managed adaptively within predefined limits determined of the effectiveness of measures and modeling (ecological, water by the Riparian Release study and landscaping the areas down- EMP quality, hydrologic) to design new approaches or optimize an stream of the dam will be undertaken to enhance certain habitat existing approach that shows promise; and, (iv) Decision mak- elements such as rapids, pools etc, if the interest of such modi- ing involving multiple stakeholders. This process is different from fication is confirmed. This will cover two main periods of time, "change management" which is a mechanism that allows changes construction (including dam construction and impoundment) and in the implementation of predefined plans. Change management operation, each of which will have different management chal- is incorporated in the Concession Agreement to allow, for exam- lenges. ple, for changes in the measures envisioned to meet the environ- mental and social objectives and in the implementation of the Proactive experimentation: Within the operational limits of the HCCEMMP. riparian release and limitations of construction activities, the flow regime and spills will be managed to achieve certain objectives. Application of Adaptive Management in the Project: Several ele- This will be done in an experimental fashion in order to test the ments of the project include management measures that involve impact of different flow regimes on the downstream areas. Simi- uncertainty and at the same time provide flexibility and therefore larly while much of the habitat modification is envisioned during could benefit from an adaptive management approach. These are the construction phase, there will be some flexibility in habitat presented in Table 6.6. modification in this area. Implementation of Mitigation Measures 205 EAMP Main Text Table 6.6: Management measures for Project elements Project Element Affected Stakeholders Management Flexibility Potential Adaptive Management Outcomes Riparian Release downstream · WMPA (NT downstream · Flow regime within predefined limits (2 cumecs · Fisheries habitat and migration improvements. of NT is part of Corridor). average weekly and complementary releases). · Water quality management. · Villages using resources · Habitat modification. · Providing resources (water, aquatic food (primarily fishing). source and riparian habitat) for wildlife. · NTPC. Water release to Nam Kathang · Villages living on the · 0 to 15 cumecs of flow provided on Monday · Water supply to villages for irrigation or other Nam Kathang. through Saturday and 0 to 10 cumecs on Sunday. use. · Variation in the flow on a daily, weekly or seasonal · Optimizing fisheries productivity in the river. basis. · Managing water quality. · Flood management. Management of release from · Villages in Gnommalat · Can vary the flow or ensure constant flow from the · Fisheries and water use in downstream chan- Regulating Dam to Downstream plain. regulating pond Monday through Saturday. nel. channel. · Sunday powerhouse shutdown will implyl a drop in · Use of water for irrigation purposes. flow from regulating pond. There is some limited · Erosion in XBF and Nam Phit. flexibility in the way this drop is managed. · Fisheries and water use in XBF. · There is potentially some flexibility in the pow- erhouse flows, however, this would largely be determined by EGAT power demands. Wildlife program · Resettlement villages. Flexibility with regard to the options taken for manag- · Management of elephant movement and hu- · PIZ and enclave villages. ing species protection, habitat and human-wildlife man elephant conflict. · WMPA. conflict. · Enhancement of habitat for birds in wetlands and fish in downstream rivers. ·Improved species protection. Monitoring: Water quality, flow and fisheries monitoring Decision making through multiple stakeholders: The decision will be undertaken in the area and this will be used to help making process should play a key role in the management of the optimize and test flow regimes. flow. The Village Commiees for the villages that live on and Reevaluation and experimental design: NTPC will provide use the Nam Kathang will make decisions on flow objectives and monitoring data and modeling of the habitat, water qual- approaches to managing the flows based on a structured consulta- ity, hydrology and potentially ecosystems of this area. This tion process that utilizes a distilled version of the modeling and will be used to test and refine flow and habitat management monitoring data. approaches. Management of Release from Regulating Pond (to Downstream Decision making through multiple stakeholders: An "envi- Channel). ronmental flow commiee" including NTPC - EMO, WMPA and local village reselement commiees representatives will NTPChascommiedtooperationoftheregulating pond to ensure make decisions on management objectives and approaches to there is a minimum of 30 m3/s in the channel in order to ensure fish flow management based on analysis and modeling provided survive (this does not apply if power station shutdown is greater by NTPC. than 32 hours). NTPC has also agreed to allow extraction of water directly from the regulating dam at the irrigation outlet only and Water Release in Nam Kathang from the lined sections of the downstream channel at designated NTPC has commied to simulating the natural flow volume locations. Adaptive management could be implemented in terms and frequency of the Nam Kathang. Upon request NTPC of operation of the regulating pond if the objectives of the opera- can change the flow within the limits of 0 to 15 cumecs Mon- tion is expanded beyond maintaining fisheries in the channel and day through Saturday and 0 to 10 cumecs on Sundays. If the appropriate multi-stakeholder decision making is included. power station shuts down NTPC have no minimum flow Proactive experimentation: The operation of the regulating pond, obligation. This flow provided to the Nam Kathang is for especially in the first years, should be done on an experimental flow into the Nam Kathang and should be above and beyond basis to minimize impacts and achieve environmental objectives the water which NTPC is allowing to be taken from the regu- in the area. lating pond and downstream channel for direct use in irriga- Monitoring: NTPC will monitor fisheries as part of the XBF strat- tion. egy and monitor erosion, water quality and hydrology as part of EMP Proactive experimentation: Depending upon the desired the EAMP. They will share this data to the district reselement objective, proactive experimentation can be undertaken to working groups as part of consultation on flow objectives. optimize the flow. This would be especially true if fisheries is Reevaluation and experimental design: NTPC will utilize its one of the objectives. water quality, erosion, fisheries and hydrology monitoring data Monitoring: NTPC will monitor fisheries as part of the XBF along with hydrologic and water quality modeling to design and strategy and monitor water quality and hydrology as part of optimize the operation of the release. the EAMP. They will provide this data to the village develop- Decision making through multiple stakeholders: Local villages ment commiee. will also have right to use the water from the downstream channel Reevaluationandexperimentaldesign: NTPCwillbeunder- for irrigation or other purposes. NTPC will be in charge of mak- taking water quality modeling and analysis on the impacts ing decisions on the flow regime but will use consultations with of the project on fisheries including the Nam Kathang. This villages living near or using the downstream channel undertaken would be used as a basis for providing potential options for through the District Reselement Working Groups to define flow managing the flows in the Nam Kathang. objectives. 206 Implementation of Mitigation Measures EAMP Main Text EMP Implementation of Mitigation Measures 207 EAMP Main Text EMP 208 Implementation of Mitigation Measures EAMP Main Text 7. Conclusion Project Environment, Impacts & Mitigation 210 Social Environment, Impacts & Mitigation 210 Benefits & Rationale 211 Conclusion D uring the past ten years of Project development, signifi- cant effort has been put into the identification of potential environmental and social impacts of the Project as well as into the development of suitable mitigation and compensation measures, where those impacts cannot be avoided. Since 1994, the Project's environmental and social assessment documents have been designed to address the World Bank's requirements, and also, more recently, the requirements of the Asian Development Bank. The Project's environmental and social documentation (EAMP, SDP and SEMFOP) presents a baseline of the areas to be affected by the Project, identify the Project's impacts, and detail the mitiga- tion measures to be undertaken. These documents are the result of numerous comprehensive studies and dialogue among various national and international institutions. Project Environment, Impacts & Mitigation 209 EAMP Main Text Project Environment, Impacts & Mitigation Dam restricting the rate of increase and decrease in discharge from the Power Station to the Xe Bang Fai; iii) aeration structures for The environmental situation, as it currently exists within the the Nam Kathang release; iv) a dedicated Downstream Channel; Project area, provides the reference by which the Project's impacts v) an Aeration Weir in the Downstream Channel; vi) an erodible and benefits can be evaluated. The Nakai Plateau, on which the section of the Downstream Channel; vii) the strengthening of the Nakai Reservoir will be created, is composed of agricultural land, Xe Bang Fai confluence; viii) partial removal of biomass from the forest, and both permanent and seasonal wetlands. The NNT reservoir area; and ix) a commitment to stop power generation NBCA constitutes the majority of the catchment of the Nakai Res- during period of natural flooding, to prevent additional over bank ervoir and is of outstanding importance in terms of regional and flooding. global biodiversity. At present, threats to the integrity of the NNT NBCA include logging, the commercial extraction of wildlife and Construction activities will potentially impact on erosion and non-timber forest products, and unsustainable agricultural prac- sedimentation, water quality, air quality and ambient noise. Spe- tices. These threats are independent of the Project. cific plans for environmental protection will be detailed in the HCCEMMP, which will be the main document for the environ- The main environmental impact of the Project will be the inun- mental management and mitigation of construction activities. The dation of 450 km2 of mostly degraded land on the Nakai Plateau, HC will be responsible for implementing the HCCEMMP. corresponding to some 40% of the Plateau's total area. All existing Both the creation of the Nakai Reservoir and the construction terrestrial vegetation in the inundated area will be lost, including activities have the potential to affect the quality of water in existing stands of Pinus laeri. This will result not only in the loss of natural water bodies. This potential for problematic water quality will be terrestrial habitats, affecting wildlife, but also in the modification greatest in the initial years following the inundation of the reser- of existing aquatic habitats, impacting water quality and aquatic voir. Various components have been incorporated into the Project diversity. design to help prevent any adverse impact upon the existing ben- The loss of any valuable habitats on the Nakai Plateau will be off- eficial uses of water. To assess whether the Project is fulfilling its set by the Project-enabled protection of the NNT NBCA. With few commitment to maintain the existing beneficial uses of water, a exceptions, the areas of habitats offset by the NNT NBCA signifi- water quality monitoring programme is being developed. This cantly exceed those that will be lost as a result of the Project. In programme will assist in the formulation of appropriate mitiga- particular, dry evergreen, upper mixed deciduous, coniferous and tion measures to help reduce the impact of any deterioration in gallery forest habitats will be fully offset by the conservation of water quality. the NNT NBCA. The loss of both lower mixed deciduous and dry A number of physical cultural resources will be affected by the dipterocarp habitats will not be completely offset within the NNT inundation of the reservoir, and by construction activities else- NBCA, however, from a national and provincial perspective, the where in the Project area. A PCR survey is being undertaken to impact on both of these habitats is not perceived as significant. identify all sites of PCR significance. The creation of the reservoir, the water quality of the reservoir, the Activities associated with the Project may lead to an increase in disruptionofmigratorypaernsofaquaticspeciesandthedestruc- the use of synthetic chemicals, such as pesticides and herbicides. Conclusion tion of spawning habitats will all impact on aquatic habitats and APest Management Plan has been developed by the Project, based biodiversity. The combined impacts may result in the local loss of on IPM principles, to manage any pest problems that may develop some species of fish not able to adapt to the new conditions. How- and to help ensure the proper handling and storage of synthetic ever, studies indicate that no species are endemic to the Project chemicals. area, as all species have been found in other river basins or outside the zone of direct impact. Social Environment, Impacts & Mitigation Inundation of the reservoir will also have implications for ter- restrial wildlife that resides there. In particular, two species of The social environment of the Nakai Plateau is characterised by importance, the Asian Elephant and white-winged duck, will high levels of poverty, poor infrastructure and public services, and lose a portion of their habitats. The long-term sustainability of the low agricultural productivity. The Xe Bang Fai is typical of many populations of displaced wildlife species on the Plateau will be lowland areas in Lao PDR and is characterized by its population's managed as part of a habitat-based programme. During the filling dependency on paddy cultivation and fishing. of the reservoir, it is likely that wildlife will become trapped on One key social impact of the Project is the relocation of approxi- islands and be vulnerable to hunting. A plan will be developed to mately 5,684 persons from 1,030 households in 17 villages, 15 of rescue trapped wildlife. which will be fully relocated, due to the creation of the Nakai The storage of water in the Nakai Reservoir and its subsequent Reservoir. Each reseled village will be provided with electricity, transferral to the Xe Bang Fai will alter the hydrology of three watersupply,schoolsandkindergartens,clinicsandother commu- major rivers: the Nam Theun, the Xe Bang Fai and the Mekong. nity infrastructure. The Project will provide each reseled village Downstream of the Nakai Dam, the reduction in discharge will with an irrigation system, and villagers will be fully supported in impact aquatic life. Adaptive management of the riparian release their choice of a range of livelihood options, including irrigated and modifications to the river's morphology will be carried out agriculture, commercial forestry, reservoir fisheries and livestock to mitigate adverse affects. The transfer of water from the Nakai husbandry. No reselement village will be of a lower standard Reservoir to the Xe Bang Fai will impact on the quantity, and pos- than the existing pilot reselement village. The management of the sibly in the first years of operations, on the quality of water in the reselement is described in the ReselementAction Plan. The plan Xe Bang Fai. While having the positive effect of improving naviga- allows for the implementation of a range of alternative livelihood tion and irrigation, the increased flows in the Xe Bang Fai will also programmes and asset compensation activities. result in alterations to the river's morphology. Such alterations will Project social safeguards also include the preparation of a proac- impact aquatic diversity and productivity. To mitigate the impacts tive plan addressing the effect of the Project on the downstream Xe on the Xe Bang Fai, several infrastructural and management strate- Bang Fai. NTPC has established a policy to anticipate and manage gies have been incorporated into the Project design, including: i) a the possible effects on the livelihoods of persons who live along Regulating Pond to store Power Station discharge ii) a Regulating the affected sections of the river and nearby tributaries. NTPC 210 Social Environment, Impacts & Mitigation EAMP Main Text will endeavour to enhance the benefits of bringing extra water to and social benefits, and will provide numerous opportunities, both this area, and to implement various measures aimed at livelihood directly and indirectly, to appreciably enhance livelihoods in the improvements. Project area and beyond. Independent experts acknowledge that The Project will provide compensation for any livelihood impacts the Project has the greatest potential of all possible hydropower resulting from damage that may occur to riverbank gardens and schemes to achieve the country's development objectives. land losses due to bank erosion caused by increased water flows. Over the 25-year Project Concession Period, GOL will receive As noted above, there is also a commitment to stop releases from approximately US$ 2 billion, which will make the Project by far the the Power Station into the Xe Bang Fai during flood periods to single largest source of foreign exchange income for Lao PDR and avoid increased overbank flooding. It is recognised that the Xe in doing so provide an opportunity to gradually reduce the coun- Bang Fai fisheries may undergo changes and the Project is commit- try's dependence on international aid.At the end of the Concession ted to fairly compensating villagers for any reduced catches. Period, the Project will transfer a 1,070 MW hydropower facility to Construction of Project components will require the temporary or GOL. All revenues accruing to the Project thereaer will be for the permanent acquisition or use of land, and compensation to the cur- benefit of GOL. GOL intends to use this revenue to develop pro- rent owners for the lost land and associated livelihoods. The loca- grammes that will contribute to the alleviation of poverty through tions or routes of Project infrastructure will be designed in order the promotion of economic and social development. The Project to minimise the effects on selements and agricultural areas. A will serve as a cornerstone for the development of Lao PDR and its baseline survey is being undertaken to identify and catalogue all integration into the region as a credible economical partner. potentially affected land. Compensation schemes are being devel- In addition to the revenue generated, the Project will have other oped for individuals who will be adversely affected. direct benefits. The Project will construct a range of infrastructure Public consultation and disclosure is playing key role in ena- with a combined value of approximately US$ 60 million, which bling the public to participate in the planning of the Project. The will be transferred to GOL aer the start of operations at no addi- Project has ensured that stakeholders' concerns, experiences and tional cost. These facilities include: i) over 100 km of upgraded and recommendations, especially from Project affected persons, are 57 km of newly constructed roads; ii) approximately 30 km of 115 integrated into the design, planning, and implementation of the kV transmission lines; iii) reselement facilities (14 new villages Project. Various meetings have increased the public's awareness with health, education, irrigation, water and electricity supply and understanding of the Project, especially with respect to the infrastructure); and iv) strengthened regional health facilities. The potential adverse impacts and proposed mitigation measures. Project will also supply employment and training opportunities at local, provincial and national levels. The implementation of the Benefits & Rationale Project will provide extensive support for capacity building and technicalassistancetoLaoPDR.GOLwillbeinvolvedin long-term Conclusion Lao PDR is recognised by the United Nations as a least developed activities related to livelihood enhancement and natural resource country, and is reliant on external aid. Almost half of its 5.4 mil- protection. The Project presents an opportunity for GOL, local lion people live in poverty, with the gross national income at just institutions, and local people to significantly upgrade the regional US $290 per capita. Hydropower, along with the harvesting of economy,improvestandardsofliving,anddivertgreaterresources timber, represent the best opportunities for Lao PDR to li itself to maintenance of the natural ecosystem. from its least developed country status. However, the large-scale From an environmental perspective, the principle offset of the export of timber has been rejected as being unsustainable and Project is the financial assistance and management support for the environmentally degrading. By contrast, the development of conservationofthe3,500km2NNTNBCA.TheProjectwillcontrib- hydroelectric power facilities represents an appropriate method ute a total of US$ 31.5 million to the management and conservation of achieving sustainable development. The Project represents an of the NNT NBCA, contributing in this way to the conservation of important opportunity for Lao PDR to obtain significant economic internationally important biodiversity. Benefits & Rationale 211 EAMP Main Text Conclusion 212 Benefits & Rationale Nam Theun 2 Power Company http://www.namtheun2.com/