Prepared for:
Upper Arun Hydro-Electric Limited
UAHEP
Shanti Priya Marg, Maharajgunj Cumulative
Kathmandu, Nepal
Impact
https://www.uahel.com.np/
uahepnea@gmail.com Assessment
+977-1-4720543 / 4720553
Appendix E
January 2024
Disclaimer: This Upper Arun Hydro-electric Project’s draft Environmental and Social Impact Assessment (ESIA) was prepared by UAHEL
broadly following Good International Industry Practices (GIIP) as those required under the Bank’s Environmental and Social Fr amework
(ESF).
The review of this ESIA is a key part of the Bank’s due diligence process and is currently ongoing. This draft ESIA may still contain gaps to
fully address all pertinent E&S issues in the project. Any gaps will be covered through supplemental studies, assessments, and/or plans that
will be completed in a reasonable timeframe to ensure compliance with the ESF.
For the benefit of potentially project affected people (PAP) and other interested stakeholders, and in alignment with the Ban k’s Policy on
Access to Information this draft ESIA is being disclosed as soon as it became available. This disclosure, however, should not be considered
s
as a final clearance of the ESIA by the World Bank.
UAHEP CUMMULATIVE IMPACT ASSESSMENT CONTENTS
26 January 2024
CONTENTS
EXECUTIVE SUMMARY ......................................................................................................................... I
Introduction ................................................................................................................................................... i
Scope of the CIA ........................................................................................................................................... i
Past, Future, and Reasonably Foreseeable Future Actions ..........................................................................ii
Valued Environmental and Social Components ............................................................................................ ii
Summary of Cumulative Impacts on the Selected VECs ..............................................................................ii
Cumulative Impact Significance ................................................................................................................... iii
Key Management Recommendations ..........................................................................................................vi
1. INTRODUCTION .......................................................................................................................... 1
1.1 Scope and Objectives .................................................................................................................... 1
1.2 Limitations...................................................................................................................................... 1
1.3 Key Terminology ............................................................................................................................ 2
1.4 Report Layout ................................................................................................................................ 2
2. APPROACH AND METHODOLOGY ........................................................................................... 4
2.1 Sources of Information ................................................................................................................... 5
2.2 Methodology .................................................................................................................................. 5
2.2.1 Overall Methodology ..................................................................................................... 5
2.2.2 Stakeholder Engagement ............................................................................................. 6
3. ADMINISTRATIVE AND REGULATORY FRAMEWORK ........................................................... 9
3.1 Authority and Responsibility......................................................................................................... 11
3.2 Environmental Impact Assessment .............................................................................................. 13
3.3 Hydropower Environmental Impact Assessment Manual, 2018 ................................................... 13
4. ARUN RIVER BASIN ................................................................................................................. 15
4.1 Standards and References .......................................................................................................... 15
4.2 General Setting ............................................................................................................................ 15
4.3 Demographic Overview ............................................................................................................... 18
4.3.1 Arun Basin in Tibet Autonomous Region .................................................................... 18
4.3.2 Arun Basin in Nepal .................................................................................................... 18
4.4 Area of Biodiversity Significance in the Arun Basin ..................................................................... 21
5. SCOPE OF CUMULATIVE IMPACT ASSESSMENT ................................................................ 23
5.1 Spatial Boundary ......................................................................................................................... 23
5.2 Temporal Boundary ..................................................................................................................... 23
5.3 Past, Present and Reasonably Foreseeable Future Actions........................................................ 24
5.3.1 Hydropower Development .......................................................................................... 24
5.3.2 Road Infrastructure .................................................................................................... 39
5.3.3 Agriculture ................................................................................................................... 42
5.3.4 Sand and Gravel Extraction ........................................................................................ 42
5.3.5 Mining ......................................................................................................................... 43
5.3.6 Natural Hazards and Climate Risks ........................................................................... 43
6. VEC SCREENING AND SELECTION ........................................................................................ 50
7. BASELINE STATUS OF SELECTED VECS ............................................................................. 55
7.1 VEC: Natural Forest Integrity ....................................................................................................... 55
7.1.1 Types of Forests in the Arun Basin ............................................................................. 55
7.1.2 Land Use/Land Cover Assessment............................................................................. 55
7.1.3 LULC of the Arun Basin in Tibet Autonomous Region ................................................ 61
7.1.4 Ecosystem Services from Forests............................................................................... 63
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UAHEP CUMMULATIVE IMPACT ASSESSMENT CONTENTS
7.2 VEC: Makalu Barun National Park ............................................................................................... 65
7.2.1 Overview ..................................................................................................................... 65
7.2.2 Management Approach ............................................................................................... 65
7.2.3 Land Use and Land Cover .......................................................................................... 65
7.2.4 Socio-economic .......................................................................................................... 66
7.2.5 Biodiversity.................................................................................................................. 66
7.2.6 MBNP Conservation Projects...................................................................................... 76
7.3 VEC: Water Resources ................................................................................................................ 76
7.3.1 Arun River Basin ......................................................................................................... 76
7.3.2 Arun River Flow Characteristics .................................................................................. 79
7.4 VEC: Fish and Aquatic Habitat .................................................................................................... 80
7.4.1 Fish Diversity in the Arun River Basin ......................................................................... 80
7.4.2 Target Fish Species .................................................................................................... 81
7.4.3 Aquatic Habitats .......................................................................................................... 85
7.5 VEC: River-based Livelihoods ..................................................................................................... 87
7.5.1 River-based Sources of Income .................................................................................. 87
7.5.2 River Use for Domestic Purposes ............................................................................... 91
7.5.3 Irrigation ...................................................................................................................... 91
7.6 VEC: Settlement .......................................................................................................................... 91
7.6.1 Overview ..................................................................................................................... 91
7.6.2 Settlement Patterns in the Arun River Basin ............................................................... 91
7.6.3 Historical Migration ..................................................................................................... 92
7.6.4 Commerce and Industry .............................................................................................. 93
7.6.5 Land and Housing ....................................................................................................... 94
7.6.6 Public Infrastructure .................................................................................................... 96
7.6.7 Local Governance ....................................................................................................... 96
7.7 VEC: Social Cohesion ................................................................................................................. 97
7.7.1 Social Capital .............................................................................................................. 97
7.7.2 Sense of Place and Cultural Practices ........................................................................ 97
7.7.3 Social Inclusion ........................................................................................................... 98
8. CUMULATIVE IMPACT ASSESSMENT .................................................................................. 102
8.1 Overview of HEP Impacts .......................................................................................................... 102
8.2 Cumulative Impacts on VEC: Natural Forest Integrity ................................................................ 104
8.2.1 Key Stressors and Impacts ....................................................................................... 104
8.2.2 Cumulative Impacts .................................................................................................. 105
8.2.3 Summary of Cumulative Impacts .............................................................................. 107
8.3 Cumulative Impacts on VEC: Makalu Barun National Park ....................................................... 107
8.3.1 Key Stressors and Impacts ....................................................................................... 107
8.3.2 Cumulative Impacts .................................................................................................. 109
8.3.3 Summary of Cumulative Impacts .............................................................................. 114
8.4 Cumulative Impacts on VEC: Water Resources ........................................................................ 114
8.4.1 Key Stressors and Impacts ....................................................................................... 114
8.4.2 Cumulative Impacts .................................................................................................. 114
8.5 Cumulative Impacts on VEC: Fish and Aquatic Habitat ............................................................. 116
8.5.1 Key Stressors and Impacts ....................................................................................... 116
8.5.2 Cumulative Impacts .................................................................................................. 117
8.5.3 Summary of Cumulative Impacts .............................................................................. 133
8.6 Cumulative Impact on VEC: River-based Livelihoods ................................................................ 135
8.6.1 Key Stressors and Impacts ....................................................................................... 135
8.6.2 Cumulative Impacts .................................................................................................. 135
8.7 Cumulative Impacts on VEC: Settlement ................................................................................... 140
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UAHEP CUMMULATIVE IMPACT ASSESSMENT CONTENTS
8.7.1 Key Stressors and Impacts ....................................................................................... 140
8.7.2 Cumulative Impact .................................................................................................... 140
8.8 Cumulative Impacts on VEC: Social Cohesion ......................................................................... 142
8.8.1 Key Stressors and Impacts ....................................................................................... 142
8.8.2 Cumulative Impact .................................................................................................... 142
8.9 Summary of Cumulative Impacts on Selected VECs ................................................................. 145
9. PROPOSED CUMULATIVE IMPACT MANAGEMENT STRATEGY ...................................... 146
9.1 Overview .................................................................................................................................... 146
9.2 Possible Mitigation and Management Measures ....................................................................... 146
9.3 Key Management Recommendations ........................................................................................ 152
10. REFERENCES ......................................................................................................................... 155
ANNEX A CIA WORKSHOP MINUTES
ANNEX B DOWNSTREAM CIA CONSULTATIONS FIELD REPORT
ANNEX C NEPAL ADMINISTRATIVE AND LEGAL FRAMEWORK
ANNEX D FISH SPECIES POTENTIALLY PRESENT IN THE ARUN BASIN
ANNEX E ESTIMATED DISTRIBUTION RANGE OF SELECT FISH SPECIES IN THE
ARUN BASIN
List of Tables
Table 1.1: Summary of Cumulative Impact Significance for each VEC ..................................................iii
Table 1.2: Non-Preferred HEP Features ................................................................................................ vi
Table 2.1: Arun River Basin CIA Study Methodology and Corresponding Report Sections .................. 5
Table 3.1: Compendium of Legal Instruments Related to Water Resources and Land Use in River
Basins...................................................................................................................................................... 9
Table 3.2: Current Administrative Framework for Water Resources .................................................... 11
Table 4.1: Key Demographic Data for the Tibet Autonomous Region in the Arun River Basin ............ 18
Table 4.2: Key Demographic Data for the Arun River Basin in Nepal .................................................. 18
Table 4.3: Areas of Biodiversity Significance within the Arun Basin ..................................................... 21
Table 5.1: Salient Features of the Main-stem HEPs ............................................................................. 26
Table 5.2: Select Salient Features of the Key Tributary Projects ......................................................... 29
Table 5.3: Hydropower Projects in the Arun River Basin ...................................................................... 33
Table 5.4: Vulnerability Index for Districts in the Arun Basin ................................................................ 44
Table 5.5: Impact of Floods and Landslides in the Study Districts (2000 –2009) .................................. 44
Table 5.6: Recorded Natural Hazards in the Arun River ...................................................................... 46
Table 5.7: Earthquakes Recorded in the Arun River Basin between 1994 and 2018 .......................... 49
Table 6.1: VEC Screening and Selection .............................................................................................. 51
Table 6.2: Final VECs and Assessment Approach ............................................................................... 53
Table 7.1: Forest Types within Eastern Nepal ...................................................................................... 55
Table 7.2: LULC Dataset....................................................................................................................... 56
Table 7.3: Proportion of LULC Classes in 2009 and 2018 ................................................................... 57
Table 7.4: Area Transfers in LULC Classes from 2009 –2018 (km2) .................................................... 60
Table 7.5: Rate of Change in LULC Classes from 1992 –2017............................................................. 60
Table 7.6: LULC in the Arun Basin within Tibet Autonomous Region .................................................. 61
Table 7.7: Ecosystem Services Valuation Methods Used .................................................................... 64
Table 7.8: Total Value of Ecosystem Services from Forest Ecosystems ............................................. 64
Table 7.9: Number of Species Types Recorded in the MBNP .............................................................. 66
Table 7.10: Bird Species that Meet IBA Criterion A2 Found in the CIA Study Area ............................. 67
Table 7.11: EBAs Overlapping the Arun Basin ..................................................................................... 68
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UAHEP CUMMULATIVE IMPACT ASSESSMENT CONTENTS
Table 7.12: Terrestrial Species of Conservation Significance .............................................................. 71
Table 7.13: Nepal DHM Flow Gauging Stations along the Arun River ................................................. 79
Table 7.14: Target Fish Species ........................................................................................................... 81
Table 7.15: Migration and Spawning Patterns for some Selected Species .......................................... 84
Table 7.16: Physical Characteristics of Tributaries along the Arun River ............................................. 85
Table 7.17: Irrigation Sources ............................................................................................................... 91
Table 7.18: District Population in 1991, 2001, and 2011 ...................................................................... 93
Table 7.19: Populations of Vulnerable Group in the Arun River Basin, by District ............................. 100
Table 8.1: Hydropower Operating Modes ........................................................................................... 102
Table 8.2: Forest Land Clearance per Development in the Arun Basin ............................................. 107
Table 8.3: HEPs planned in the MBNP ............................................................................................... 109
Table 8.4: Estimated Land Clearance in the MBNP ........................................................................... 110
Table 8.5: Suitability of Spawning Potential for Tributaries in Temperature Zones ............................ 120
Table 8.6: Likely Cumulative Impacts from Impoundment in the Three Zones .................................. 127
Table 8.7: Likely Cumulative Impacts from Low Flow in the Three Zones ......................................... 130
Table 8.8: Likely Cumulative Impacts from Peaking in the Three Zones ........................................... 132
Table 8.9: Categories for Baseline Ecological Status ......................................................................... 134
Table 8.10: Changes in Ecological Integrity for the Three Zones ....................................................... 134
Table 8.11: Stressors and Cumulative Impacts on Livelihoods .......................................................... 135
Table 8.12: Settlement Stressors and Impacts ................................................................................... 140
Table 8.13: Social Cohesion Stressors and Impacts .......................................................................... 142
Table 8.14: Summary of Cumulative Impact Significance for each VEC ............................................ 145
Table 9.1: Possible Mitigation and Management Measures ............................................................... 147
Table 9.2: Non-Preferred HEP Features ............................................................................................. 152
List of Figures
Figure 1: CIA Study Area in Nepal .......................................................................................................... v
Figure 2.1: Comparing an ESIA and a CIA ............................................................................................. 4
Figure 2.2: Conceptual CIA Process ....................................................................................................... 4
Figure 4.1: Koshi Basin including the Arun Catchment ........................................................................ 16
Figure 4.2: Average Streamflow in the Nepal Koshi Basin ................................................................... 17
Figure 4.3: Arun River Basin ................................................................................................................. 17
Figure 4.4: Arun Basin in Nepal ............................................................................................................ 20
Figure 4.5: Key Biodiversity Areas in the Arun River Basin .................................................................. 22
Figure 5.1: HEP Arrangements on the Arun River ................................................................................ 28
Figure 5.2: Planned HEPs in the Arun River Basin .............................................................................. 30
Figure 5.3: Schematic Diagram of the Sapta Koshi Project .................................................................. 31
Figure 5.4: Location of the Koshi Barrage and Sapta Koshi High Dam ................................................ 32
Figure 5.5: Power Development Plan in Eastern Nepal ....................................................................... 38
Figure 5.6: Road Infrastructure in the Arun River Basin ....................................................................... 40
Figure 5.7: North-South Highway (Khandbari-Kimathanka) ................................................................. 41
Figure 5.8: Schematic of the Mid Hill Highway ..................................................................................... 41
Figure 5.9: Mining Site in the Arun Basin .............................................................................................. 43
Figure 6.10: Glacial Lakes in the Arun Basin ........................................................................................ 46
Figure 5.11: Landslide Hotspots in the Lower Arun Basin .................................................................... 48
Figure 6.1: VEC screening process ...................................................................................................... 50
Figure 7.1: Arun Basin Land Cover in 2008 and 2018 .......................................................................... 56
Figure 7.2: Gains and Losses in LULC between 2009 and 2018 ......................................................... 58
Figure 7.3: LULC in the Arun Basin in Tibet Autonomous Region........................................................ 62
Figure 7.4: EBAs Overlapping the Arun Basin and MBNP ................................................................... 69
Figure 7.5: Arun River Drainage............................................................................................................. 77
Figure 7.6: Arun River Basin .................................................................................................................. 78
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UAHEP CUMMULATIVE IMPACT ASSESSMENT CONTENTS
Figure 7.7: Average Annual Rainfall in the Koshi Basin .......................................................................... 79
Figure 7.8: Three River Temperature Zones in the Arun Basin ............................................................ 86
Figure 7.9: CIA Consultations with Fishing Communities ..................................................................... 88
Figure 7.10: Key Fishing Rivers and Nearby Communities .................................................................. 89
Figure 7.11: Settlement LULC Change in the Arun River Basin from 2009–2018 ............................... 92
Figure 7.12: Market Centres in the Arun River Basin ........................................................................... 95
Figure 8.1: General Characteristics of Peaking HEPs ........................................................................ 103
Figure 8.2: Schematic of a Typical HEP and Key Environmental and Social Impacts ...................... 103
Figure 8.3: Cumulative Impact Pathway for VEC: Natural Forest Integrity ......................................... 104
Figure 8.4: Gains and Losses to Forest Land between 2009 and 2018 ............................................. 105
Figure 8.5: Cumulative Impact Pathway for VEC: Makalu Barun National Park ................................ 108
Figure 8.6: Developments Planned in the MBNP ............................................................................... 112
Figure 8.7: Glacial Lakes in the MBNP ............................................................................................... 113
Figure 8.8: Cumulative Impact Pathway for VEC: Aquatic Species and Habitat ................................ 117
Figure 8.9 Arun River Rafting Map ..................................................................................................... 139
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UAHEP CUMMULATIVE IMPACT ASSESSMENT CONTENTS
Acronyms and Abbreviations
ADB Asian Development Bank
BOOT Build, Operate, Own, and Transfer
BS Bikram Sambat (Nepali Calendar)
CBS Central Bureau of Statistics
CCI Chamber of Commerce and Industry
CEDB Commerce and Economic Development Bureau
CF Community Forest
CFPCC Central Fisheries Promotion and Conservation Centre
CFUG Community Forest Use Group
CH Critical Habitat
CIA Cumulative Impact Assessment
CR Critically Endangered
DAI Direct Area of Influence
DCC District Coordination Committee
DEM Digital Elevation Model
DFID Department for International Development
DFRS Derbyshire Fire and Rescue Service
DHM Department of Hydrology and Meteorology
DKSHEP Dudhkoshi Storage Hydropower Project
DNA Deoxyribonucleic Acid
DNPWC Department of National Parks and Wildlife Conservation
DoED Department of Electricity Development
DOI Department of Information
DPR Detailed Project Report
DWIDP Department of Water Induced Disaster Prevention
EBA Endemic Bird Area
EFlow Environmental Flow
EIA Environmental Impact Assessment
EN Endangered
EPA Environmental Protection Agency
EPC Energy Performance Contract
EPR Environment Protection Rules
ERM ERM-Siam Company Limited
ERMC Environment and Resource Management Consultancy Limited
ESF Environmental and Social Framework
ESIA Environmental and Social Impact Assessment
ESS1 Assessment of Management of Environmental and Social Risks and Impact
FAO Food and Agriculture Organization
FECOFUN Federation of Community Forest Users Nepal
FGD Focus Group Discussion
FPIC Free, Prior and Informed Consent
FRB Fisheries Research Branch
FS Feasibility Study
GAP Gender Action Plan
GBV Gender Based Violence
GDP Gross Domestic Product
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UAHEP CUMMULATIVE IMPACT ASSESSMENT CONTENTS
GESI Global Enabling Sustainability Initiative
GLOF Glacial Lake Outburst Floods
GRM Grievance Redressal Mechanism
HDI Human Development Index
HDP Hydropower Development Policy
HEP Hydroelectric Project
HH Household
HPP Hydropower Project
IBA Important Bird Area
IBAT Integrated Biodiversity Assessment Tool
IBN Investment Board Nepal
ICIMOD International Centre for Integrated Mountain Development
IEE Initial Environmental Examination
IFC International Finance Corporation’s
IKHPP Ikhuwa Khola Hydropower Project
ILO International Labour Organization
INGO International Non-Governmental Organization
IUCN International Union for the Conservation of Nature
IWRM Integrated Water Resources Management
KAHEP Kimathanka Arun Hydropower Project
KBA Key Biodiversity Areas
KHARDEP Kosi Hill Area Rural Development Programme
KV Kilovolt
LC Least Concern
LGU Local Governance Unit
LLR Land and Land Resources
LULC Land Use and Land Cover
LUP Land Use Plan
LUZ Land Use Zone
MBNP Makalu Barun National Park
ML Magnitude
MoALD Ministry of Agriculture and Livestock Development
MoE Ministry of Energy
MoEWRI Ministry of Energy, Water Resources and Irrigation
MoFE Ministry of Forests and Environment
MT Metric Ton
MW Megawatt
NA Not Applicable
NARC National Agriculture Research Centre
NDC Nationally Dalit Commission
NEA Nepal Electricity Authority
NEFIN Nepal Federation of Indigenous Nationalities
NERC Nepal Electricity Regulatory Commission
NGO Non-Governmental Organization
NPC National Planning Commission
NPR Nepalese Rupee
NT Near Threatened
NTFP Non-Timber Forest Product
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UAHEP CUMMULATIVE IMPACT ASSESSMENT CONTENTS
ODA Overseas Development Administration
OECD Organisation for Economic Co-operation and Development
PFS Pre-Feasibility Study
PPP Public Private Partnership
PS Performance Standard
QNNP Qomolangma National Park
RAP Resettlement Action Plan
RFFA Reasonably Foreseeable Future Action
ROR Run-of-River
RPGCL Rastriya Prasaran Grid Co Ltd
SEP Stakeholder Engagement Plan
SKSKI Sun Koshi Sapta Koshi Investigation
ToR Terms of Reference
TIP Trafficking in Persons
TL Transmission Line
UAHEP Upper Arun Hydroelectric Project
UN United Nations
UNDP United Nations Development Programme
UNDRIP United Nations Declaration on the Rights of Indigenous Peoples
USAID United States Agency for International Development
USD United States Dollar
VDC Village Development Committees
VEC Valued Environmental, Social and Ecosystem Component
VU Vulnerable
WAPCOS WAPCOS Limited
WECS Water and Energy Commission Secretariat
WUA Water Users Association
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UAHEP CUMULATIVE IMPACT ASSESSMENT EXECUTIVE SUMMARY
EXECUTIVE SUMMARY
Introduction
The Project Terms of Reference (ToR) call for the preparation of a Cumulative Impact Assessment
(CIA) for the Upper Arun Hydroelectric Project (UAHEP) and the Ikhuwa Khola Hydropower Project
(IKHPP) in conjunction with the Environmental and Social Impact Assessment (ESIA). Accordingly, the
ERM team has conducted a CIA for the UAHEP and IKHPP within the Arun River Basin in accordance
with the International Finance Corporation’s (IFC's) Good Practice Handbook on Cumulative Impact
Assessment and Management (IFC 2013).
The objective of the CIA is to assess the impacts of UAHEP and IKHPP, in combination with other
existing and proposed hydroelectric projects (HEPs) and external stressors within the Arun River Basin.
The specific objectives are to:
◼ Identify valued environmental, social and ecosystem components (VECs) that could be impacted
cumulatively in areas potentially affected by the HEPs, including the UAHEP and IKHPP,
considering input from stakeholders and the scientific community through a consultation process.
◼ Identify other existing and planned HEPs and associated transmission line and access road
developments, other road developments, and external stressors (e.g., climate change and natural
hazards) that could cumulatively impact VECs.
◼ Assess the potential cumulative impacts on VECs from past, existing, and planned HEPs, road
developments, and other and external stressors.
◼ Recommend project-level as well as strategic planning-level recommendations for minimizing
negative cumulative impacts and maximizing the positive impacts associated with hydropower
development at a basin scale.
Scope of the CIA
The Arun River is the largest trans-Himalayan river passing through Nepal and also has the greatest
snow and ice-covered area of any Nepalese river basin. The Arun River drains more than half of the
area contributing to the Sapta Koshi river system. Overall, the Arun Basin covers an area of 30,041
km2, of which 24,888 km2 (83%) is situated in China and 5,153 km2 (17%) in Nepal. The CIA Study Area
(Figure 1) focuses on the Upper Arun River reach, and considers significant impacts in the upstream
reach within the Tibet Autonomous Region (TAR) of China, as well as downstream towards its
confluence with the Sapta Koshi.
Most of the projects identified within the boundary are hydropower, transmission line, and transportation
projects. A limit of 10 years is adequate to frame the hydropower projects considered (as shown in
Figure 1 and detailed in Section 5.3.1) in this CIA, as it is assumed that these projects will be at least
under construction within this period. The temporal extent of these impacts is longer, as HEPs typically
have a long life expectancy. Hydropower projects are designed to operate for at least 50 years, and are
expected to operate for 80 or more years, especially if they implement an effective sediment
management strategy to minimize sediment deposition in the project reservoir. It is difficult to predict
impacts with any certainty that far into the future; as such, the temporal scope of the CIA was
established as a maximum 50-year timeframe.
The timeframe for potential hydropower project decommissioning is so far in the future as to make any
impact assessment unreliable. Further, the transmission line and transportation projects will be
maintained and repaired, but are unlikely to be decommissioned. For these reasons, decommissioning
of these projects was not considered in this CIA.
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UAHEP CUMULATIVE IMPACT ASSESSMENT EXECUTIVE SUMMARY
Past, Future, and Reasonably Foreseeable Future Actions
Key past, present and future actions within the Arun Basin include hydropower, road infrastructure,
agriculture, and sand and gravel extraction – as well as other external stressors (e.g., climate change
and natural hazards) – as summarized below:
◼ Hydropower: Within the Arun River Basin there are 9 operating HEPs, 22 under construction (i.e.,
obtained construction license), 12 have applied for a construction license, and 17 have obtained a
survey license, all of which total approximately 4,763 megawatt (MW).
◼ Road infrastructure: The North-South Highway (Koshi Highway) connects India to China across
the Himalayan Mountains in Nepal. The construction of the Koshi Highway will also use materials
extracted from the Arun River. The 1,776 km Mid Hill Highway is under construction to connect
east and west Nepal, and partially passes through the Arun Basin.
◼ Agriculture: Agricultural is the predominant economic activity in the Koshi Hills (Sankhuwasabha,
Bhojpur, Dhankuta, and Terhathum districts). The agricultural system is predominantly subsistence
in nature, except in a few areas accessed by roads, where the intensive cultivation of vegetables
is being practiced.
◼ Sand and gravel extraction: Gravel, sand and stone are extracted from Shaba Khola, Sishwa Khola,
and Nepa Khola and partly from the Arun River. The extracted materials are typically used within
the district, for instance, for road construction.
◼ Natural hazards and climate risks: Sankhuwasabha and Bhojpur districts are ranked as having
“high” climate change vulnerability (which includes changes in rainfall and temperature, landslides,
flooding, droughts, and glacial lake outburst floods) and Dhankuta is ranked as “moderate.”
Valued Environmental and Social Components
Valued environmental, social, and ecosystem components (VECs) are defined as fundamental
elements of the physical, biological, or socio-economic environment that are likely to be the most
sensitive receptors to the cumulative impacts of other projects and stressors in combination with the
proposed project. Using the results of stakeholder consultations, field surveys, data analysis, and
literature review, the following seven VECs were selected for the CIA study: natural forest integrity,
Makalu Barun National Park (MBNP), water resources, fish and aquatic habitat, river-based livelihoods,
settlement, and social cohesion.
Summary of Cumulative Impacts on the Selected VECs
There would be significant adverse cumulative impacts on the river and communities if each of the 30+
planned HEPs in the Arun River Basin (Table 5.3) were constructed. These impacts would be further
exacerbated by road and transmission line development, climate change, and natural hazards, which
would be even more significant for vulnerable groups.
In general, hydropower projects that are on the main stem of the Upper Arun River (i.e., Kimathanka,
Upper Arun, Arun-4) will affect the MBNP Buffer Zone and fish movement/migration. Projects on Upper
Arun River tributaries, especially clear water tributaries, will affect important fish spawning areas and
generally result in more forest clearing and impacts on ecosystem services per MW generated than
large mainstem dams.
Hydropower projects located on the mid Arun River (i.e., Arun-3) will have more significant biological
impacts, but similar social impacts on those projects on the Upper Arun. Projects on the lower Arun
River (i.e., Lower Arun, Sapta Koshi) will likely have more significant physical, biological, and social
impacts. Projects located on glacial fed tributaries will generally have fewer biological impacts than
those located on clear water tributaries.
If the planned main stem hydropower projects are built with limited reservoir storage capacities (which
appears to be the case, according to currently available information, with the exception of Sapta Koshi),
26 January 2024 Page 2
UAHEP CUMULATIVE IMPACT ASSESSMENT EXECUTIVE SUMMARY
there would likely be relatively small effects on flow regulation. More severe impacts would likely incur
from fragmentation, which would be significant under a full development scenario of over 30 hydropower
projects, and result in a significant reduction in river connectivity. Moreover, even a single dam on the
main stem typically results in significantly higher fragmentation than dams on tributaries (Grill 2014).
Moreover, a reduction in river connectivity could significantly impact on the ecological integrity of the
Arun River network, which would negatively affect livelihoods, particularly of fishing-based livelihoods
and vulnerable groups.
Cumulative Impact Significance
The focus of this CIA is to predict to what extent HEPs may contribute, in combination with the other
proposed projects and activities selected for this assessment, to cumulative impacts on the selected
VECs. The significance of cumulative impacts is considered for each VEC – the significance is not
evaluated in terms of the magnitude of change, but in terms of VEC response and the resulting condition
and sustainability. Cumulative impact significance definitions used in this CIA are:
◼ Negligible – VEC would not experience noticeable changes
◼ Moderate – VEC would experience noticeable changes, but within natural variations
◼ Substantial – VEC would experience changes beyond natural variation, but within its range of
tolerance/resilience
◼ High – VEC would experience changes that would likely exceed the range of tolerance/resilience
and the viability of the VEC would be threatened
A summary of the cumulative impact significance for the selected VECs is provided in the Table 1.1
below.
Table 0.1: Summary of Cumulative Impact Significance for each VEC
VEC Metric Cumulative Impact Significance
Natural forest integrity Forest loss and fragmentation Upper Arun River Basin: High
Middle Arun River Basin: Moderate
Lower Arun River Basin: High
Makalu Barun National Park Forest loss and fragmentation MBNP: High
Water resources River flow High
River water quality Moderate
Geomorphology Moderate
Sediment transport Upper Arun River: Moderate
Lower Arun River: High
Fish and aquatic habitat Changes in ecological integrity Cold Zone: High
Cold-Cool Zone: High
Cool Zone: Moderate
River-based livelihoods Impacts on irrigation Upper Arun River Basin: Negligible
Lower Arun River Basin: High
Impacts on artisanal fishing Overall basin: Negligible
Sabha Khola: High
Impacts on rafting outfitters If Sapta Koshi Project is built: Moderate
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UAHEP CUMULATIVE IMPACT ASSESSMENT EXECUTIVE SUMMARY
VEC Metric Cumulative Impact Significance
Settlement Changes in settlement Upper Arun River Basin: High
demographics patterns
Social cohesion Impacts on sense of place Upper Arun River Basin: High
Deterioration or loss of social Upper Arun River Basin: High
safety nets
Mid/lower Arun River Basin: Moderate
Access to local power Upper Arun River Basin: High
structures/social capital Mid/lower Arun River Basin: Moderate
Generation of social tension Upper Arun River Basin: High
Mid/lower Arun Basin: Moderate
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UAHEP CUMULATIVE IMPACT ASSESSMENT EXECUTIVE SUMMARY
Figure 1: CIA Study Area in Nepal
Source: ERM 2020
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UAHEP CUMULATIVE IMPACT ASSESSMENT EXECUTIVE SUMMARY
Key Management Recommendations
The key recommendations regarding managing cumulative impacts within the Arun River Basin include:
◼ River Basin Planning: Even with the adoption and effective implementation of recommended
mitigation and management measures, construction and operation of the over 30 HEPs currently
proposed within the Arun River Basin will exceed the carrying capacity of the river basin and
inevitably result in significant adverse cumulative environmental and social impacts. Over 30 HEPs
within this relatively small basin is simply not sustainable. The Government of Nepal should develop
a River Basin Management Plan, which protects key fish spawning tributaries, minimizes social
impacts, and establishes guidelines relative to fish passage, sediment management, and water
quality. There is guidance available for preparing river basin management plans, such as
hydropower by design approach recommended by The Nature Conservancy (2017). This
Management Plan should critically review the need for this many projects and prioritize the most
important and most sustainable ones. HEPs with the features listed in Table 1.2 are not preferred
and should be carefully considered before approving.
Table 0.2: Non-Preferred HEP Features
Non-preferred HEP Features Example HEPs in the Arun Basin
HEPs located in the MBNP Core Area and
Apsuwa I, Upper Apsuwa, Upper Isuwa, and Lower
other protected areas and key biodiversity Barun
areas (KBAs)
HEPs requiring long access roads and/or Additional field studies need to confirm access and
transmission line routes, but potentially including Lower
transmission lines that result in significant Barun, Chujung Khola, Upper Ikhuwa Khola Small, Super
habitat fragmentation and/or physical Sabha Khola Small, Sabha Khola-B, Sabha Khola A,
displacement Apsuwa I, Upper Apsuwa, Upper Isuwa
To be determined based on feasibility studies
HEPs with long diversion reaches documenting the proposed length of the diversion reach
HEPs located along important fish
To be determined, but effective fish passage at Sapta
migratory routes without effective fish Koshi High Dam and Lower Arun are very important
passage plans
Additional field studies need to confirm, but potentially
including Chujung Khola, Ikhuwa Khola, Ikhuwa Khola
HEPs located on clear water tributaries Small, Sankhuwa Khola, Lower and Upper Chirkhuwa
that are important for fish spawning Khola, Hewa Khola, Sabha Khola C, Lakhuwa Khola,
Maya Khola, Piluwa Khola
HEPs requiring significant physical Sapta Koshi High Dam Multipurpose Project, possibly
resettlement others based on site-specific field studies
HEPs impacting areas providing important To be determined based on site specific field studies
ecosystem services
◼ Protection of MBNP: There are five HEPs planned on the Upper Arun River along the edge of
MBNP Buffer Zone (Kimathanka Arun, UAHEP, Arun-3, Arun-4, and Lower Arun), three planned
HEPs on tributaries in the MBNP Core Area (Lower Barun, Apsuwa I, and Upper Isuwa), and four
planned HEPs on tributaries within the MBNP Buffer Zone (Upper Apsuwa, Isuwa, Lower Isuwa,
and Kasuwa). The need for these HEPs within the Core Area and those within the Buffer Zone, but
with lower capacity, should be carefully balanced with their environmental and social impacts,
including the construction of project access roads and transmission lines that contribute to
fragmentation.
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UAHEP CUMULATIVE IMPACT ASSESSMENT EXECUTIVE SUMMARY
Support the management initiatives of the MBNP conservation authorities and Community
Conservation Programmes, so that they are better able to cope with the increased pressure from
influx and other impacts. Support should be towards improved park facilities (e.g., offices,
communications, vehicles, and maintenance capacity), infrastructure to access areas for easier
management, boundary demarcation, staff training and equipment, revision of management plans,
and others. A mechanism needs to be developed at the level of the Nepal Ministry of Finance to
retain funds generated from hydropower to be allocated to MBNP management purposes.
◼ Natural forest integrity (impact of transmission lines on birds): Transmission lines represent key
risk to birds and all of these HEPs will require construction of new transmission lines. To minimize
the risk to birds within MBNP and other KBAs, projects should minimize transmission line crossings
of rivers/important bird flyways, be required to share transmission lines corridors, and design
transmission line voltages to accommodate future planned hydropower projects; in addition, all
projects should adopt bird friendly transmission line design to minimize bird collision and
electrocution risk.
◼ Migratory fish (provision of fish passage facilities): Golden mahseer and other migratory fish
species are found within the Arun River Basin. It is important that fish passage is provided along
their migratory routes at proposed HEPs to maintain their access to critical spawning grounds. It is
especially important for the lower main stem projects to provide effective fish passage, as they
could block migratory fish access to a significant number of spawning areas – this is specifically
the case for the Sapta Koshi and Lower Arun HEPs, as there is documented important spawning
habitats upstream from these dams. The Sapta Koshi as currently proposed (over 200 m high) is
too high for a fish ladder, but other fish passage options should be explored like trap and trucking
or even the creation of a nature-like fishway, as the topography at this project is more suitable for
this option than farther upstream on the Arun River. The Arun-3 HEP is currently approved without
fish passage, which will prevent mid-range migrants (e.g., common snow trout) from reaching
potential habitats upstream. This project is already under construction, so it is likely too late to
retrofit a fish ladder, but options like trap and trucking should be considered, at least as an adaptive
management measure, if monitoring indicates that the population of common snow trout upstream
from Arun-3 HEP is not sustainable. The approved fish hatchery will likely contribute to the loss of
native fish stocks. Tributary streams important for fish spawning (e.g., Ikhuwa Khola) should be
protected (e.g., remain free of hydropower projects).
◼ Fish and aquatic habitat (provision of EFlow): Provision of a scientifically-based environmental flow
(eFlow) within the diversion reaches of the proposed HEPs is critical to maintain the ecological
integrity of the Arun River and its tributaries and the ecosystem services that they provide. The
goal should be to maintain naturally reproducing populations of all native fish species in each
segment of the Arun River between the main stem hydropower projects. This will require protecting
key clear water tributaries, which could be used by the common snow trout and golden mahseer
for spawning. In the case of the Upper Arun, this would mean protecting Ikhuwa Khola from
hydropower development.
◼ River-based livelihoods: Conduct regular socialization, consultation, and monitoring activities with
relevant stakeholders; ensure that a HEP grievance mechanism is well socialized; and develop
relevant community development programs for the HEP-affected people in coordination with
government authorities. Provide livelihood restoration for residents affected by the conversion of
the Arun River into a series of reservoirs, diversion reaches, and modified flow reaches.
◼ Social cohesion: Develop a strategic plan and provide funding to help local indigenous peoples
(especially upstream from Num) to retain their social identify, cohesion, and heritage in response
to both significant improvements in access to this area and labour influx.
◼ Cultural heritage: A cultural heritage management plan should be developed to manage impacts
on tangible and intangible cultural heritage resources. In addition, a chance finds procedure shall
be developed and implemented for all tangible heritage resources that may be uncovered during
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UAHEP CUMULATIVE IMPACT ASSESSMENT EXECUTIVE SUMMARY
the construction period – the procedure should be disclosed to the energy performance contract
(EPC), contractors, and community. HEPs must also consult local leaders before construction
activities to discuss cultural heritage sites and understand when planned ceremonies/rituals take
place within/near the construction area.
◼ Settlement (management of influx and project-related social issues): Maximize the recruitment of
local workers where feasible and provide training to increase the capacity of eligible local people;
establish a grievance mechanism (including a gender based violence [GBV] reporting and
management system) accessible for all community groups (and workers) to report concerns
associated with workers, conduct investigations into the grievances, and address them in a timely
manner.
◼ Sediment management (related to water resources): All proposed HEPs must include an effective
strategy for managing sediment, both to sustain their own operations, as well as to maintain
downstream river geomorphic functioning and minimize the river’s erosion potential. Sediment
flushing during the monsoon season should be considered as part of the sediment management
strategy, but project developers must demonstrate that this sediment will not silt up the project’s
diversion reaches.
◼ Capacity Building, Regulatory Review, Monitoring, and Enforcement. There is a need for more
capacity building within the key hydropower regulatory agencies in Nepal. The Department of
Electricity Development (DoED) and Ministry of Forests and Environment (MoFE) need to carefully
review proposed HEPs to ensure they are properly managing key environmental and social
impacts, including physical and economic displacement, EFlows, fish passage, sediment
management, and habitat fragmentation. There is also a need for effective construction and
operation phase monitoring and enforcement. A recent review of hydropower projects in Nepal
(Dangol and Uprety 2019) found that many that hydropower construction contractors were unaware
of required mitigation measures and many HEPs were not complying with environmental impact
assessment (EIA) approval conditions. Recent studies have found little compliance with required
EFlows and required fish ladders are not designed for native fish, thereby undermining their likely
effectiveness. Further, little government compliance monitoring or enforcement is occurring and
there are no efforts at adaptive management. A much more robust compliance monitoring and
enforcement program is needed, together with adaptive management, to achieve sustainable
hydropower in Nepal. The DoED and MoFE should consider more use of participatory monitoring
of HEP construction and operation by local communities, especially in the Arun River Basin, which
is far from agency headquarters in Kathmandu and more difficult to monitor because of distance
and cost, and stronger enforcement measures.
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UAHEP CUMULATIVE IMPACT ASSESSMENT INTRODUCTION
1. INTRODUCTION
The Project Terms of Reference (ToR) call for the preparation of a Cumulative Impact Assessment
(CIA) for the Upper Arun Hydroelectric Project (UAHEP) and the Ikhuwa Khola Hydropower Project
(IKHPP) in conjunction with the Environmental and Social Impact Assessment (ESIA).
The Project’s ToR states that the CIA will include:
◼ Cumulative effects of hydropower development and other projects, activities, and stressors in the
Arun River Basin
◼ Cumulative effects on the riverine fishery of Arun River Basin, including rare and endangered
species
◼ Cumulative effects on culture and well-being of ethnic minorities whose lives are dependent on
natural resources and eco-system services
1.1 Scope and Objectives
In conjunction with the ESIA, the ERM team has conducted a CIA for UAHEP and IKHPP within the Arun
River Basin in accordance with the International Finance Corporation’s (IFC’s) Good Practice Handbook:
Cumulative Impact Assessment and Management (IFC 2013). This Good Practice Handbook provides a
methodology for identifying the most significant cumulative impacts, focusing on valued environmental
and social components (VECs), which are: (1) rated as highly valued by potential project-affected
communities and/or the scientific community; and (2) cumulatively impacted by the project under
evaluation, and by other projects and/or by natural environmental and social external stressors.
This methodology, which was applied in this CIA (see Section 2) follows a six-step process. The
methodology is considered consistent with the IFC Performance Standards (PS), especially PS 1 –
Assessment and Management of Environmental and Social Risks and Impacts, and PS 6 – Biodiversity
Conservation and Sustainable Management of Living Natural Resources (IFC 2012).
The objective of the CIA is to assess the impacts of UAHEP and IKHPP, in combination with other existing
and proposed HEPs and external stressors within the Arun River Basin. The specific objectives are:
◼ Identify valued environmental, social and ecosystem components (VECs) that could be impacted
cumulatively in areas potentially affected by the HEPs, including the UAHEP and IKHPP,
considering input from stakeholders and the scientific community through a consultation process.
◼ Identify other existing and planned HEPs and associated transmission line and access road
developments, other road developments, and external stressors (e.g., climate change and natural
hazards) that could cumulatively impact VECs.
◼ Assess the potential cumulative impacts on VECs from past, existing, and planned HEPs, road
developments, and other and external stressors.
◼ Recommend project-level as well as strategic planning-level recommendations for minimizing
negative cumulative impacts and maximizing the positive impacts associated with hydropower
development at a basin scale.
1.2 Limitations
The CIA report was drafted in view of the following limitations and caveats:
◼ Incomplete information about other projects and activities (e.g., the information is not available in
the public domain)
◼ Incomplete baseline information on the selected VECs
◼ Uncertainty with respect to the implementation of future projects
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UAHEP CUMULATIVE IMPACT ASSESSMENT INTRODUCTION
1.3 Key Terminology
The following are definitions of some of the key terms used in this CIA (IFC 2013):
◼ Cumulative impact: Impacts that result from the successive, incremental, and/or combined effects
of an action, project, or activity added to other existing, planned, and/or reasonably anticipated
actions, projects, or activities. For practical reasons, the identification, assessment, and
management of cumulative impacts are limited to those effects generally recognized as important
on the basis of scientific concern and/or concerns of affected communities.
◼ CIA: Cumulative impact assessment is an instrument to consider the cumulative impacts of a
project in combination with impacts from other relevant past, present, and reasonably foreseeable
developments, as well as unplanned but predictable activities enabled by the project that may occur
later or at a different location (World Bank 2018, Annex 1 [d]).
◼ Other projects: Existing, planned, or reasonably expected future developments, projects and/or
activities potentially affecting VECs.
◼ External stressors or drivers: Sources or conditions that could affect or cause physical,
biological, or social stress on VECs, such as natural environmental and social drivers, human
activities, and external stressors. These can include climate change, population influx, natural
disasters, or deforestation, among others.
◼ VEC: Environmental and social components considered important by the scientific community
and/or potentially-affected communities. VECs may include:
- Physical features, habitats, wildlife populations (e.g., biodiversity, water supply)
- Ecosystem services (e.g., protection from natural hazards, provision of food)
- Natural processes (e.g., water and nutrient cycles, microclimate)
- Social conditions (e.g., community health, economic conditions)
- Cultural heritage or cultural resources aspects (e.g., archaeological, historic, traditional sites)
VECs reflect the public and scientific community’s “concern” about or special interest in
environmental, social, cultural, economic, or aesthetic values. VECs are considered the ultimate
recipients of cumulative impacts, because they tend to be at the end of ecological pathways.
1.4 Report Layout
The remaining sections of this Report are structured as follows:
Section 2 Approach and Methodology, including a detailed description of the CIA methodology
and a determination of the CIA spatial and temporal boundaries
Section 3 Administrative and Regulatory Framework, as relevant to the study including the
implementation of mitigation measures
Section 4 Arun River Basin General Context, including a description of the general
environmental and social setting
Section 5 Scope of the Arun River Basin CIA, including the spatial and temporal boundaries,
project development scenarios, preliminary VECs, and past, present and reasonably
foreseeable future actions
Section 6 Valued Environmental and Social Components, including the screening and
selection results and a description of their present conditions
Section 7 Baseline Status of Selected VECs
Section 8 Cumulative Impact Assessment, including a description of the impacts and a
determination of their significance
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UAHEP CUMULATIVE IMPACT ASSESSMENT INTRODUCTION
Section 9 Proposed Cumulative Impacts Management Strategy
Section 10 References
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UAHEP CUMULATIVE IMPACT ASSESSMENT APPROACH AND METHODOLOGY
2. APPROACH AND METHODOLOGY
Unlike an environmental and social impact assessment (ESIA), which focuses on a project as a
generator of impacts on various environmental and social receptors, a CIA focuses on VECs as the
receptors of impacts from different projects and activities (see Figure 2.1). In a CIA, the overall resulting
condition of the VEC and its related viability are assessed.
Figure 2.1: Comparing an ESIA and a CIA
ESIA: Project-Centered Perspective CIA: VEC-Centered Perspective
Source: IFC 2013
The IFC’s Cumulative Impact Assessment and Management: Guidance for the Private Sector in
Emerging Markets Good Practice Handbook (IFC 2013) outlines a six-step process (see Figure 2.2),
which is iterative and flexible, with some steps having to be revisited in response to the results of others.
The steps are described in detail in Section 2.2.
Figure 2.2: Conceptual CIA Process
Source: IFC 2013
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UAHEP CUMULATIVE IMPACT ASSESSMENT APPROACH AND METHODOLOGY
2.1 Sources of Information
ERM have reviewed existing documentation and information provided by the NEA and/or available in
the public domain, including the following sources:
◼ Primary data collected as part of the UAHEP ESIA and CIA
◼ IKHPP Initial Environmental Examination (Water Resources Consult (P.) Ltd., et al. 2015)
◼ Arun-3 Environmental Impact Assessment (EIA) (WAPCOS 2015)
◼ Arun-4 Feasibility and EIA Study Interim Design Report (DoED, date not available)
◼ Lower Arun Feasibility and EIA Study Interim Design Report (DoED, date not available)
◼ Num-Kimathanka Road (Koshi Highway) EIA (ERMC (P.) Ltd., 2019)
◼ Kimathanka Arun Feasibility Study Report
◼ Nepal government agencies and national and regional development plans including Department of
Electricity Development (DoED), Nepal Electricity Authority (NEA), Department of Energy, Water
Resources and Irrigation (DoEWRI), Ministry of Forest and Environment (MoFE), Ministry of Energy
(MoE), Ministry of Energy, Water Resources and Irrigation (MoEWRI), Ministry of Agriculture and
Livestock Development (MoALD), Department of Water Supply and Sanitation, Department of
Roads, and Department of Disaster Water Induced Management
◼ Research and academic institutions including the International Union for the Conservation of
Nature (IUCN) Nepal, National Agriculture Research Centre (NARC), Fisheries Research Branch
(FRB), Central Fisheries Promotion and Conservation Centre (CFPCC)
◼ Other articles and literature, as detailed in Section 10 References.
2.2 Methodology
2.2.1 Overall Methodology
This CIA follows a six-step process based on IFC’s Good Practice Handbook on CIA. These steps are
described in Table 2.1.
Table 2.1: Arun River Basin CIA Study Methodology and Corresponding Report
Sections
Step CIA Report Section
Step 1: Determine spatial and temporal boundaries Sections 5.1 and 5.2
Determine the timeframe and spatial boundaries (study area) of the CIA. Spatial and temporal
boundary
Step 2a: Hold initial public consultations Section 2.2.2
Consult with relevant government agencies, universities, and other key Stakeholder
stakeholders to identify the VECs, developments, and external natural and social Engagement
stressors within the study area.
Step 2b: Identify preliminary VECs. Section 6 VEC
Develop a preliminary list of VECs based on the consultations conducted in Step Screening and Selection
2a.
Step 2c: Identify all developments and natural and social stressors that may Section 5.3, Past,
affect the VECs Present and
Based on findings from the initial public consultations and literature review, identify Reasonably
past and present actions (other projects and other stressors) that have influenced Foreseeable Future
the current condition of the resources or VECs within the CIA study area, as well Actions
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UAHEP CUMULATIVE IMPACT ASSESSMENT APPROACH AND METHODOLOGY
Step CIA Report Section
as reasonably foreseeable future actions (RFFA) that may affect VECs in the
future.
Step 2d: Screen VECs Section 6, VEC
Screen potential VECs based on the following criteria: Screening and Selection
− Would the UAHEP or IKHPP affect this VEC?
− Would other identified projects/stressors in the area potentially affect this VEC
cumulatively?
− Would the impacts be potentially significant/meaningful?
− Apply other screening criteria if necessary.
Step 2e: Select final VECs Section 6, VEC
Further define and validate these VECs to determine the final VECs that will be Screening and Selection
the ultimate focus of the CIA assessment. VEC indicators and thresholds are
defined during this process.
Step 3: VEC baseline Section 7, Baseline
Collect primary and secondary information on the final VECs. Define the baseline Status of Selected
for the final VECs, their spatial and temporal extent, existing conditions, sensitivity VECs
to change, resilience/recovery time, existing stressors, and trends in condition.
VEC indicators and thresholds are refined during this step. This assessment is
informed by public consultations and baseline studies conducted as part of the
CIA and ESIA.
Step 4: Assess cumulative impacts on VECs Section 8, Cumulative
Assess the cumulative impacts arising from interactions between UAHEP, IKHPP, Impact on Selected
other projects, and other stressors (as identified in Step 2c) on the VECs. Focus VECs
on projects and stressors that have a temporal and spatial overlap with one
another. Evaluate the significance of predicted cumulative impacts on the
viability/sustainability of the affected VECs.
Step 5: Evaluate significance of the cumulative impacts on the predicted Section 8, Cumulative
future conditions of VECs Impact on Selected
Evaluate the significance of predicted cumulative impacts on the viability/ VECs
sustainability of the affected VECs.
Step 6: Design and implement management and mitigation measures Section 9, Proposed
Design and implement additional management and mitigation measures to those Management Strategy
already identified in the ESIA required to manage UAHEP and IKHPP’s
contribution to the predicted cumulative impacts. This includes not only the
management of impacts where the project has control, but also consulting and
liaising with government officials and third parties where impacts are outside of the
project’s direct control.
2.2.2 Stakeholder Engagement
The UAHEP developed a Stakeholder Engagement Plan (SEP) early on in the Project’s planning phase
to ensure effective stakeholder engagement during the course of the Project. The SEP includes
information on key standards and legislation guiding stakeholder engagement, stakeholder
identification, analysis and mapping, strategies for communication with each stakeholder group, and
grievance redressal mechanism (GRM), among other things.
The UAHEP has, thus far, conducted multiple rounds of consultations on various issues, including
scoping meetings to identify environmental and social concerns for ESIA, consultation meetings on the
Resettlement Action Plan (RAP) to solicit feedback on proposed entitlements, consultation with
indigenous people to identify issues particular to indigenous peoples, and consultations with women
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UAHEP CUMULATIVE IMPACT ASSESSMENT APPROACH AND METHODOLOGY
based organizations and individuals to inform the Gender Action Plan (GAP). VECs were identified
based on these consultations. Stakeholders consulted during the UAHEP ESIA included:
◼ Local communities including Dalits, indigenous communities and women groups near the UAHEP
and IKHPP
◼ Local NGOs
◼ Local authorities at the ward, district and rural municipality level
◼ Agencies including Waters Source and Divisional Office, Agriculture Knowledge Centre, Divisional
Forest Office, Drinking Water and Sanitation Units, Tourism Development Centres
◼ Federation of Community Forest Users Group
◼ Local businesses, health posts, police offices, schools
◼ Workers’ camps
Additionally, the Project conducted separate consultations to collect primary data during UAHEP CIA
consultations at the government-level and with communities near and downstream from the UAHEP.
This CIA also draws upon the environmental and social data gathered as part of the UAHEP ESIA
stakeholder engagements, as detailed above. A summary of the stakeholder consultations that were
conducted specifically for this CIA are summarized below:
◼ UAHEP CIA consultation workshop held on 11 November 2019 in Kathmandu. Representatives
from the UAHEP, DoED, Water and Energy Commission Secretariat (WECS), NARC, and Makalu
Barun National Park were in attendance to discuss the tentative VECs and potential cumulative
impacts of the UAHEP and other hydropower projects in the Arun River Basin. The minutes from
this workshop are presented in Annex A.
◼ UAHEP CIA downstream consultations were conducted by the CIA Team in Khandbari Urban
Municipality, Sankhuwasabha District in March 2020. Specific settlements for CIA consultations
were chosen based on interaction and recommendation by the local community, as well as the
local authorities, based on the identified VECs. All major local government bodies concerned with
the VECs were also consulted. The objective was to understand the dependency of communities
in the Arun Basin on fishing, use of rivers for drinking and irrigation, religious and spiritual activities,
recreational activities, and use of community forest, as well as to understand various infrastructure
projects planned or under development.
The team conducted focus group discussions (FGDs) and key informant interviews (KIIs) with
various stakeholders to understand dependencies on the identified VECs, including:
- Ethnic communities (e.g., Bhote, Kumal, Majhi, Rai, Limbu, Dalit and Bahun/Chhetri)
- Local government representatives at Khandbari Urban Municipality, District Coordination
Committee (DCC), Water Resources and Divisional Irrigation Office, Agriculture Knowledge
Center, Divisional Forest Office, Drinking Water and Sanitation Unit
- Federation of Community Forest Users Group
- Local communities and businesses
A brief field report for these consultations is provided in Annex B.
Based on these consultations, a set of preliminary VECs were identified as follows:
◼ Physical components:
- Air quality
- Noise
- Water resources
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UAHEP CUMULATIVE IMPACT ASSESSMENT APPROACH AND METHODOLOGY
◼ Biological components:
- Natural forest integrity
- Makalu Barun National Park
- Fish and aquatic habitat
◼ Social components:
- River-based livelihoods
- Settlement
- Social cohesion
Following the identification of preliminary VECs, screening and selection of VECs was conducted
(Section 6) to determine the final VECs for the basis of this CIA.
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UAHEP CUMULATIVE IMPACT ASSESSMENT ADMINISTRATIVE AND REGULATORY FRAMEWORK
3. ADMINISTRATIVE AND REGULATORY FRAMEWORK
A number of existing legal instruments have a direct bearing on hydropower development and water
resources management, as listed in Table 3.1. However, the only reference to CIAs within these
existing legal instruments is in the 2018 Hydropower Environmental Impact Assessment Manual, as
detailed in Section 3.3.
Table 3.1: Compendium of Legal Instruments Related to Water Resources and
Land Use in River Basins
Constitution
Constitution of Nepal, 2015
Plans
National Water Plan, 2005
Brief Guideline for Preparation of Water Use Master Plan, 2017
Strategies
Agriculture Development Strategy 2015–2035
Forest Sector Strategy 2016–2025
National Energy Crisis Reduction and Electricity Development Decade, 2015
National Energy Strategy of Nepal, 2013
National Water Resources Strategy, 2002
Rural water supply and Sanitation National Strategy, 2004
Policies
Climate change Policy 2019
Draft Water Resources Policy, 2019
Forest Policy,2000
Hydropower Development Policy (HDP), 1992 and Hydropower Development Policy, 2001
Irrigation Policy, 2013
Land Acquisition, Resettlement and Rehabilitation Policy, 2015
Land Use Policy, 2015
National Agriculture Policy, 2004
Public-Private Partnership Policy, 2015
Water-induced Disaster Management Policy, 2015
Acts
Aquatic Protection Act, 1960
Civil Code, 2017
Consumer Protection Act, 1999
Criminal Code, 2017
Development Board Act, 2706
Disaster Risk Reduction and Management Act, 2017
Draft Irrigation Act, 2015
Draft Water Supply and Sanitation Act, 2018
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UAHEP CUMULATIVE IMPACT ASSESSMENT ADMINISTRATIVE AND REGULATORY FRAMEWORK
Electricity Act, 1992
Environment Protection Act, 2019
Essential Commodity Protection Act, 1955
Forest Act, 1993 and Forest Act, 2019
Guthi Corporation Act, 1976
Industrial Enterprises Act, 1992
Inter-governmental Fiscal Management Act, 2017
Land Acquisition Act, 1977
Lands Act, 1964
Land Use Act, 2019
Local Government Operation Act, 2017
Natural Resources and Fiscal Commission, 2017
Nepal Electricity Authority Act, 1984
Nepal Electricity Regulatory Commission Act, 2017
Public Private Partnership (PPP) and Investment Act, 2019
Water Resources Act, 1992 and Draft Water Resources Act, 2019
Water Supply Management Board Act, 2006
Provincial Acts
Irrigation Act, 2018 (P-1)
Rules
Drinking Water Rules, 1998
Electricity Rules, 1993
Environment Protection Rules, 2020
Forest Rules, 2020
Irrigation Rule, 2000
Rafting Rule, 2006
Water Resources Rule, 1993
Guidelines/Directives/Manuals/ Working Procedures
Directives for Use of Forest for National Prioritized Projects, 2017
Guidelines to Provide Land for Construction of Infrastructure Projects in Conservation Areas 2024
Directives on Licensing of Hydropower Projects, 2016
Drinking Water Service Operation Directive, 2012
EIA/IEE Working Procedure for Hydropower and Transmission Lines, 2016
Hydropower Environmental Impact Assessment (EIA) Manual, 2018
Gender Equality and Social Inclusion Mainstreaming Guideline for Irrigation and Water Induced Disaster
Prevention Sectors, 2014, Ministry of Irrigation
Guidelines for Study for Hydropower Projects, 2003
Land Ceiling Exemption Order, 2017
Local Energy Development Directive, 2017
National Drinking Water Quality Standard, 2005
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UAHEP CUMULATIVE IMPACT ASSESSMENT ADMINISTRATIVE AND REGULATORY FRAMEWORK
National EIA Guideline, 1993
3.1 Authority and Responsibility
The Constitution of Nepal, 2015 mandates the federal government to conserve water resources and to
develop policies and standards for multiple water uses; and mandates the provincial government to
manage water resources within their jurisdiction. Drinking water and watershed management is under
the jurisdiction of local government. However, water resource management is also under the concurrent
rights of the state, province and local government.
Table 3.2 summarizes Nepal’s administrative framework with respect to legislative matters pertaining
to water resources management at the federal, provincial, and local levels.
The Three Tiers Government Project Classification and Distribution Standard , 2076 BS (2019 AD) –
issued by Nepal Planning Commission and approved by Federal Council of Ministers – refers to guiding
principles from Constitution of Nepal, 2015 and the Natural Resources and Fiscal Commission Act,
2017. The Standard recommends that energy projects (hydro and solar) more than 20 MW/33 kilovolt
(KV) transmission lines shall fall under federal jurisdiction; projects from 3 to 20 MW/11 to 33 KV
transmission lines shall fall under provincial jurisdiction; and projects up to 3 MW shall fall under local
jurisdiction. Notably, the Standard’s local jurisdiction provision contradicts 11(2)-N(3), which provides
that projects up to 1 MW fall under local jurisdiction.
Table 3.2: Current Administrative Framework for Water Resources
River Basins
The function, duties and rights of the WECS are:
◼ To review multipurpose, mega and medium scale water resources projects before they are sanctioned by
the Government of Nepal, and recommend their implementation.
◼ To formulate necessary policies and strategies conducting study, research, survey and analysis with regard
to various aspects of water resources and energy development in keeping with priorities and targets of the
Government of Nepal.
◼ To analyze bilateral or multilateral projects relating to the development of water resources and energy, to
formulate policies in this respect, and to review the detailed study and analysis of such projects.
◼ To enact necessary laws pertaining to the development of water resources and energy.
◼ To establish the coordination among national and sectoral policies relating to water resources and energy
sector.
Federal
Organizational roles of different federal government agencies:
◼ MoEWRI: implements policies, laws, standards and regulations for water resources sustainable
development, conservation, uses, water resources distribution
◼ Nepal Electricity Authority (NEA)
◼ Department of Electricity Development (DoED): reviews and forwards Initial Environmental Examination
(IEE) to concerned agencies for approval
◼ Ministry of Forests and Environment (MoFE): approves of environmental study – IEE or EIA
◼ Investment Board Nepal (IBN): Facilitates environmental clearance/approvals for large projects
◼ WECS: assists Government of Nepal, different ministries relating to water resources, and other related
agencies in the formulation of policies and the planning of projects in the energy resources sector
◼ Federal matters include international boundary river, preservation of water resources, big hydro-electricity
and irrigation projects, environment management, national forests within provinces, water use, environment
management, national parks and reserves, wetlands, forest policy, land use policies, and tourism
development.
Provincial
◼ Governments at the provincial level have been in place since January-February 2018
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◼ Provincial matters include provincial roads, land management records, mining, research and management,
national forest within provinces, water use, and environment management.
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Local
◼ The district assembly and district coordination committees (DCCs) coordinate between the Federal
government, provincial government offices, village bodies, and municipalities within a district; monitor
development and construction work; manage natural disaster resilience; and issue working procedures,
directives, and standards within their jurisdiction.
◼ Associations such as community forest user groups (CFUGs), village development committees (VDCs),
and aama samuhas (or mothers’ groups) have an established governance mechanism for managing
resources such as forests, pasturelands, irrigation systems, and community assets.
◼ Local governance units (LGUs) co-exist with traditional and formal institutions such as the CFUGs to
implement legislative matters within their jurisdiction on watersheds, wildlife, mining protection, small hydro
projects, alternative energy, and issues to do with the environment.
◼ Each LGU has an established administrative structure that includes departments such as social justice,
environment development and economic affairs.
Source: ERM 2019
3.2 Environmental Impact Assessment
The Environment Protection Rules (EPR) 2020, which came into force on 15 June 2020 (repealing EPR
1997) is the major guiding document for conducting EIAs and IEEs for projects in Nepal. The current
EPR does not specifically address cumulative impacts or require a CIA.
3.3 Hydropower Environmental Impact Assessment Manual, 2018
The Hydropower Environmental Impact Assessment Manual (Hydropower EIA Manual) encourages
hydropower project sponsors to manage cumulative impacts within a given river basin. The International
Finance Corporation is currently working with the Ministry of Forests and Environment and the
International Centre for Integrated Mountain Development (ICIMOD) to encourage application of CIA in
Nepal. The IFC sponsored a workshop on CIA in Kathmandu in 2017 and supported the development
of the Hydropower EIA Manual. Shown in Box 3.1 are the CIA references within the Hydropower EIA
Manual.
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Box 3.1: CIA References in the Hydropower EIA Manual
Source: MoFE 2018
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4. ARUN RIVER BASIN
4.1 Standards and References
ERM followed the IFC’s Good Practice Handbook on CIA and also considered the guidance documents
indicated in the consulting services ToR, complemented by other available international good practice
guidance, including:
◼ Performance Standards on Environmental and Social Sustainability (IFC 2012)
◼ Good Practice Note: Environmental, Health, and Safety Approaches for Hydropower Projects (IFC
2018a)
◼ Good Practice Handbook: Environmental Flows for Hydropower Projects, Guidance for the Private
Sector in Emerging Markets (IFC 2018b)
◼ Draft Cumulative Impact Assessment Guidelines for Hydropower Projects in the Lao People’s
Democratic Republic (IFC no date)
◼ Environmental and Social Framework (ESF). ESS1: Assessment of Management of Environmental
and Social Risks and Impact (World Bank 2018, paragraph 23)
◼ Cumulative Effects Assessment Practitioners Guide for the Canadian Environmental Assessment
Agency (Hegmann et al. 1999)
◼ Strategic Environmental Assessment for Hydropower Sector Planning – Guidance Material
(Annandale et al. 2014)
◼ Joint Initiative on Rapid Basin-wide Hydropower Sustainability Assessment Tool (USAID et al.
2010)
◼ Cumulative Impacts – A Good Practice Guide for the Australian Coal Mining Industry (Franks et al.
2010)
4.2 General Setting
There are nine major river systems in Nepal (i.e., Mahakali, Karnali, Babai, Rapti, Gandaki, Bagmati,
Kamala, Koshi, and the Kankai). The Koshi River system (Bharati et al. 2019) is the largest and
originates from Nepal’s four highest Himalayan peaks (Mt. Everest – 8,850 m, Mt. Jannu – 7,710 m, Mt.
Makalu – 8,462 m, and Mt. Cho Oyu – 8,201 m). The Koshi is also called the Sapta Koshi for its seven
Himalayan tributaries in eastern Nepal: Indrawati, Sun Koshi, Tama Koshi, Dudh Koshi, Liku, Arun, and
Tamor (Figure 4.1).
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Figure 4.1: Koshi Basin including the Arun Catchment
Source: Penton 2017
The Arun River is the largest trans-Himalayan river passing through Nepal and also has the greatest
snow and ice-covered area of any Nepalese river basin. The Arun River drains more than half of the
area contributing to the Sapta Koshi river system.
In Tibet Autonomous Region, the Arun River is known as Men Qu (Moniqu) in its upper reaches north
of Xixabangma and then as the Peng Qu (Pumqu) for most of its course north of the Himalayan crest.
After progressing eastward through arid grasslands, the Peng Qu turns south at the confluence with the
Yarn Qu (Yeyuzangbu). The Peng Qu crosses the Himalayan crest at an elevation of about 2,175 m
and becomes known as the Arun in Nepal. South of the Himalayan crest, the flow volume of the Arun
increases rapidly downstream in the seasonally-humid environment of east Nepal. The Nepal portion
of the Arun Basin represents only 17% of the total basin area, but it provides more than 70% of the
Arun River’s total flow at its confluence with the Sapta Koshi (Kattelmann 1990). Over 80% of the annual
precipitation of 1,500 mm occurs during the monsoon season (June-September) (Pradhan and Sharma
2017). Figure 4.2 shows the average streamflow in the Koshi Basin of Nepal.
The Arun Basin covers an area of 30,041 km2, of which 24,888 km2 (83%) is situated in China and 5,153
km2 (17%) is in Nepal (Figure 4.3). The general demographics and areas of biodiversity significance of
the Arun Basin in China and Nepal are summarized below.
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Figure 4.2: Average Streamflow in the Nepal Koshi Basin
Source: Penton 2017
Figure 4.3: Arun River Basin
Source: ERM 2020
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4.3 Demographic Overview
4.3.1 Arun Basin in Tibet Autonomous Region
The Arun River Basin in Tibet Autonomous Region is encompassed within one prefecture, namely
Shigatse (also known as Xigazê). Key demographic data for Shigatse Prefecture is provided in Table
4.1. Note that data specific to Shigatse is not available for all indicators, for these, data for the entire
Tibet Autonomous Region has been provided.
Table 4.1: Key Demographic Data for the Tibet Autonomous Region in the Arun
River Basin
Area in the Arun Basin TAR
Total land area (km2) 24,873 -
Total forest area (km2) 1,136 (4.6%) -
Population density (people per km2) 3.9 2.6
(for Shigatse Prefecture)
Total male population - 50.2%
Total female population - 49.8%
Total literacy rate - 43.5
Male literacy rate - 50.0
Female literacy rate - 30.1
Poverty rate - 24.5%
Human Development Index (HDI) - 0.57
Sources: China National Bureau of Statistics, 2002, 2010; Land Management Bureau of Tibet Autonomous Region, 1992;
Tibetan Statistical Yearbook, 2000; UNDP, 2013
4.3.2 Arun Basin in Nepal
In Nepal, the Arun River Basin is situated across three districts of Province No. 1, namely:
Sankhuwasabha, Bhojpur, and Dhankuta (Figure 4.4). These districts are located within an area often
referred to as the “Koshi Hills.” Key demographic data for these three districts are provided in Table
4.2. Statistics and profiles of communities of indigenous people in these districts are provided in Section
7.
Table 4.2: Key Demographic Data for the Arun River Basin in Nepal
Sankhuwasabha Bhojpur Dhankuta
Total land area (km2) 3,476.8 1,526.8 901.1
Total forest area (km2) 1,561.0 728.8 367.8
Total population (people) 158,742 182,459 163,412
Total male population 47.4% 47.2% 46.8%
Total female population 52.6% 52.8% 53.2%
Total households (HHs) 34,624 39,419 37,616
Male headed HH 72.6% 72.6% 70.7%
Female headed HH 27.4% 27.4% 29.3%
Total literacy rate 69.4% 69.3% 74.4%
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Sankhuwasabha Bhojpur Dhankuta
Male literacy rate 77.5% 78.4% 82.4%
Female literacy rate 62.2% 61.4% 67.4%
Poverty rate 21.0% 24.4% 15.9%
Human Development Index (HDI) 0.49 0.48 0.52
Income from agriculture, forestry, and fishery 81.92% 87.18% 79.90%
(%)
Sources: CBS 2011; Poverty rate: Nepal small area estimate of poverty (CBS); State of Nepal’s Forests (DFRS 2015); Nepal
Human Development Report (NPC and UNDP 2014)
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Figure 4.4: Arun Basin in Nepal
Source: ERM 2020
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4.4 Area of Biodiversity Significance in the Arun Basin
Areas of biodiversity significance within the Arun River Basin (within Nepal and Tibet Autonomous
Region of China) are summarized in Table 4.3 and identified in Figure 4.5, which includes Protected
Areas, Key Biodiversity Areas (KBA), Endemic Bird Areas (EBA), and Nature Reserves. Additional
details regarding the Makalu Barun National Park (MBNP) are provided in Section 7.2.
Table 4.3: Areas of Biodiversity Significance within the Arun Basin
Name Type Location Summary
Makalu Barun Protected Nepal – within The MBNP Core Area and its Buffer Zone is a biodiversity
National Park Areas and the Arun River hotspot of international importance. It is the world ’s only
(MBNP) KBA Basin protected area with an elevation gain of more than 8,000 m
enclosing tropical forest as well as snow-capped peaks. It
covers an area of 1,500 km2 in Solukhumbu and
Sankhuwasabha districts, and is surrounded by a Buffer
Zone to the south and southeast with an area of 830 km 2.
Tamur Valley and KBA and Nepal – Tamur The Tamur Valley and Watershed KBA and IBA (20,000 ha)
Watershed IBA River Basin has extensive forests of oak (Quercus spp.) and chinquapin
(Castanopsis spp.), with rich patches of Rhododendron
spp. A total of 260 bird species have been recorded from
this site
Sagarmatha Protected Nepal – Koshi Covers an area of 124,400 ha and includes the highest
National Park Area and Major River mountain on Earth, Mt. Sagarmatha (Mt. Everest) at 8,850
KBA Basin m, as well as another seven peaks over 7,000 m. The area
is home to several rare species such as the snow leopard
and the red panda.
Kanchenjunga KBA Nepal – Tamur Kanchenjunga Conservation Area was established in 1997,
Conservation Area River Basin and measures 203,500 ha. Ranging in altitude from 1,200
to 8,586 m, it covers a range of bioclimatic zones, like other
conservation areas of the region, with a concomitant rich
biodiversity.
Eastern Himalayas EBA Several This EBA follows the Himalayan range east from the Arun-
countries – Kosi valley of eastern Nepal, through Bhutan, north-east
overlapping India, south-east Tibet Autonomous Region (China) and
with the Arun north-east Myanmar to south-west China
Basin
Central Himalayas EBA Several This EBA extends through the Himalayas from the extreme
countries – east of Nepal to the extreme west, and into adjacent
overlapping regions of India.
with the Arun
Basin
Qomolangma National China – Qomolangma National Park (QNNP) is the highest altitude
National Park Park Shigatse biosphere reserve in the world, protecting approximately
Prefecture, 3.4 million ha of the central Himalaya in Tibet Autonomous
Tibet Region (China). It contains or abuts several of the world’s
Autonomous highest peaks, including Qomolangma (Chinese:
Region, China Zhulangmafeng) or Mt. Everest 8,850 m).
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Figure 4.5: Key Biodiversity Areas in the Arun River Basin
Source: ERM 2020
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5. SCOPE OF CUMULATIVE IMPACT ASSESSMENT
5.1 Spatial Boundary
The IFC Cumulative Impact Assessment (CIA) Guidelines recommend the following rules of thumb to
determine the spatial boundary of a CIA:
◼ Include the area that will be directly affected by the project or activity (in this case, the UAHEP),
which is known as the Direct Area of Influence (DAI) in the traditional ESIA sense.
◼ List the important resources (VECs) within the DAI.
◼ Define if these VECs occupy a wider area beyond the DAI.
◼ Consider the distance that an effect can travel, and other impacts that the VEC may be exposed to
within its range.
Delineating an appropriate spatial boundary for a hydropower CIA depends on where active change is
occurring in a watershed and what the significance of those changes is (Lein 2002). This helps to keep
the CIA focused, and give priority to issues of concern (MacDonald 2000). To account for accumulated
changes in biophysical parameters of a river system, Squires et al. (2010) suggest that a CIA framework
considers changes from river headwaters to mouth.
The spatial boundary may vary depending on the VEC assessed. For example, the study area for
livelihoods encompasses settlements that are potentially most reliant on the rivers and streams within
the Arun Basin (i.e., located near each side of the Arun River and its main tributaries). Moreover, there
are certain common economic, social, and cultural features that link upstream, midstream, and
downstream river reaches of the Arun River Basin. Likewise, there exist certain similarities and
differences in resource utilization patterns (for example, in agriculture, fishing, and other riverine-based
livelihoods) and economic conditions (linked to market access, gender, inequality, and other income-
related issues).
The CIA study area and the overall Arun River Basin boundary are shown in Figure 4.4. Although the
CIA study area focuses on the Upper Arun River reach, the CIA also considers significant impacts in
the upstream reach within Tibet Autonomous Region of China, as well as downstream towards its
confluence with the Sapta Koshi.
5.2 Temporal Boundary
Temporal delineation for a CIA is a challenge due to the inherent uncertainty about potential future
projects and activities. The following are the basic rules of thumb to determine temporal boundaries for
the assessment according to the IFC CIA Guidelines.
a) Use the time frame expected for the complete life cycle of the proposed development
(including construction, operation, and decommissioning).
b) Specify whether the expected time frame of the potential effects of proposed development can
extend beyond (a).
c) Use the most conservative time frame between (a) and (b).
d) Use professional judgment to balance between overestimating and underestimating, and make
sure to document the justification or rationale.
e) Exclude future actions if (i) they are outside the geographical boundary, (ii) they do not affect
VECs, or (iii) their inclusion cannot be supported by technical or scientific evidence.
Most of the projects identified within the spatial boundary are hydropower, transmission line, and
transportation projects. A limit of 10 years is adequate to frame the hydropower projects considered
(Section 55.3.1), as it is assumed that these projects will be at least under construction within this
period. The temporal extent of these impacts is longer as HEPs typically have a long life expectancy.
Hydropower projects are designed to operate for at least 50 years and expected to operate for 80 or
more years, especially if they implement an effective sediment management strategy to minimize
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sediment deposition in the project reservoir. It is difficult to predict impacts with any certainty that far
into the future; as such, the temporal scope of the CIA was established as a maximum 50-year
timeframe.
The timeframe for potential hydropower project decommissioning is so far in the future as to make any
impact assessment unreliable. Further, the transmission line and transportation projects will be
maintained and repaired, but are unlikely to be decommissioned. For these reasons, the
decommissioning of these projects was not considered in this CIA.
5.3 Past, Present and Reasonably Foreseeable Future Actions
This section identifies past and present actions that have influenced the current condition of the
resources or VECs within the CIA study area, as well as reasonably foreseeable future actions (RFFA).
Key past, present, and future actions within the Arun Basin include hydropower, road infrastructure,
agriculture, sand and gravel extraction, and mining, as well as other external stressors (e.g., climate
change and natural hazards). The actions presented in this section have been compiled from
stakeholder consultations and literature reviews. The timeframe for this analysis was determined based
upon the construction and operational phases of UAHEP and IKHPP and the RFFAs that could be
predicted. As such, a timeframe of 50 years has been established for the analysis. Predictions beyond
this timeframe are considered to be unreliable.
5.3.1 Hydropower Development
Within the Arun River Basin there are there are 9 operating HEPs, 22 under construction (i.e., obtained
construction license), 12 have applied for a construction license, and 17 have obtained a survey license,
all of which total approximately 4,763 megawatt (MW). Table 5.1 summarizes the projects that have
been identified to date. The approximate locations of select HEPs are shown in Figure 5.1. Table 5.3
indicates the status of each project.
Given the lack of available data for many of these HEPs, this CIA focuses on under-construction and
planned projects located on the main stem (Arun River), including (from north-to-south): Kimathanka
Arun, UAHEP, Arun-4, Arun-3, and Lower Arun; and key tributary HEPs including: IKHPP, Upper
Ikhuwa Khola Small, and Lower Barun. These hydropower projects also involve access roads and
transmission lines, which are discussed in more detail in the following subsections. There is generally
little information on the smaller hydropower projects located on tributaries of the Arun River, as many
of these are only in the early license stage of development. These projects are included in this CIA, but
more qualitatively and on a programmatic basis.
Projects on the downstream Koshi River (i.e., the existing Koshi Barrage and the planned Sapta Koshi
High Dam Multipurpose Project) are also considered in this CIA due to the potentially significant impacts
of these projects on the identified VECs considered in this CIA.
Hydropower on the Arun River in Tibet Autonomous Region
There are currently no existing or planned hydropower projects on the Bum-chu/Peng Qu River (the
Arun River in the TAR) and its tributaries. The majority of operating/planned hydropower projects in
TAR operations are located in the western reaches of the region, on the Yarlung Tsanpo and Jinsha
rivers.
Main-stem Projects on the Arun River in Nepal
Below are descriptions of the main-stem HEPs on the Arun River in Nepal. A summary of the salient
features for these HEPs is provided in Table 5.1 and a schematic diagram of these projects is shown
in Figure 5.2.
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Kimathanka Arun HEP
The proposed 450 MW Kimathanka Arun Hydropower Project (KAHEP) is a peaking located
approximately 8 km upstream from the UAHEP headworks. Located within the Makalu Barun National
Park Buffer Zone, the proposed intake is approximately 1.6 km downstream from the border with TAR
at Kimathanka Arun Pass and the dam bed elevation is approximately 1,968 masl. The proposed
powerhouse is located 1.6 km downstream from the confluence of Chhujan Khola with Arun River, at
an elevation of approximately 1,665 masl.
Upper Arun HEP
The UAHEP is a peaking run-of-river (PRoR) type hydroelectric project on the Arun River in
Sankhuwasabha District of eastern Nepal, about 15 km south of the international border with TAR and
220 km east of Kathmandu. The proposed dam site is in a narrow gorge about 350 m upstream from
the Arun River’s confluence with the Chepuwa Khola. The proposed UAHEP power plant site is located
approximately 16 km downstream from the dam site, near the Arun River’s confluence with the Leksuwa
River. The right bank of the Arun River, at the proposed UAHEP site, falls within the MBNP Buffer Zone,
which extends, according to park officials, to the middle of the Arun River. The proposed UAHEP dam
site is, therefore, located partially within the Buffer Zone. The project has an authorized capacity of
1,063.36 MW, and will operate in a 6-hour daily peaking mode during the dry season.
Arun-4 HEP
Arun-4 HEP is a run-of-river (RoR) project planned approximately 18 km downstream from the UAHEP
dam (about 1.5 km downstream from the UAHEP powerhouse) and 14 km upstream from Arun-3 HEP
dam, near Gola village, with a total installed capacity of 473 MW. The dam site will be located at an
elevation of approximately 1,065 masl, and the tailrace at 835 masl. It is understood that the Nepal
Department of Electricity Development (DoED) is developing this project.
Arun-3 HEP
Arun-3 HEP is a 900 MW PRoR project located approximately 32.0 km downstream from the UAHEP
dam (about 15.5 km downstream from the UAHEP powerhouse). Construction of the Arun 3-HEP
commenced in 2018, and is expected to take seven years according to the project’s EIA. The dam site
is located near Num Village in Sankhuwasabha District on the Arun River, about 60 km from Tumlingtar.
The dam site will be located at an elevation of approximately 790 masl, and the tailrace at 525 masl.
Lower Arun HEP
The Lower Arun HEP was planned as a PRoR (6 hours of daily peaking) project located immediately
downstream from the Arun-3 HEP, and will take advantage of some of its infrastructure. Water from the
tailrace of Arun-3 HEP will flow directly to the Arun River. Thereafter, the Lower Arun HEP diversion
structure will start. The updated supplementary EIA for the project envisages constructing the power
plant as a cascade facility to Arun 3 HEP. It will have no dam structure. The installed capacity for
cascade operation is expected to be 669 MW. The project is being developed by SJVN, which is also
constructing the Arun-3 HEP.1
1
See: https://sjvn.nic.in/businessprojectdetails/28/5/46
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Table 5.1: Salient Features of the Main-stem HEPs
Salient Kimathanka Upper Arun Arun 4 Arun 3 Lower
Features Arun2
Status Planned Planned Planned Under Planned
construction
Dam river km 431 km 418 km 400 km 386 km 365 km
Operation PRoR – 6 PRoR – 6 hrs RoR PRoR RoR –
hrs cascade
with Arun 3
MW 450 MW 1040 MW 473 MW 900 MW 669 MW
Dam height 70 m 100 m 13 m 68 m -
Avg flow 198 m3/s 217 m3/s 256 m3/s 297 m3/s -
Design 143 m3/s 235 m3/s 253 m3/s 343 m3/s 344 m3/s
discharge
Net head 370 m 508 m 216 m 287 m 212 m
EFlow 4.8 m3/s 5.4 m3/s 4.3 m3/s 6.3 m3/s From Arun
3 and
augmented
river flow
Fish passage Unlikely No Unlikely No -
FEL 2,035/2,025 1,640/1,625 m 1,078 m 845/835 m -
m
Total storage 10.2 M m3 5.1 M m3 13.9 M m3 -
volume
Reservoir 3.0 km 2.1 km 4.5 -
length
Reservoir 33.8 ha 20.1 ha 66.3 ha -
surface area
Diversion 10 km 16.5 km 9 km 18 km -
reach length
Tailwater 1,650 m 1,084 m ~835 m ~525 m ~285 m
elevation
Transmission 18.5 km 5.8 km 13.5 km 310 km 2 km
line length
Access road Koshi Hwy Koshi Hwy Koshi Koshi Hwy Koshi Hwy
Hwy
Land take Uncertain 180 ha Uncertain 180 ha 184 ha
requirement
Elevation 2,035–1,650 1,640–1,084 m 1,078– 845–525 m 532–285 m
impact m 835 m
2
Supplementary EIA of Lower Arun HEP, 2023:
https://ibn.gov.np/uploads/files/SEIA%20Lower%20Arun%20HEP%20(669%20MW)%20-upload_1693738160.pdf
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Salient Kimathanka Upper Arun Arun 4 Arun 3 Lower
Features Arun2
Max 59 hours 26 hours <24 hrs 61 hours 55 hours
residence
time
Distance 0.8 km 1.2 km 0.5 km 0.1 km 0.0 km
from PH to
next
downstream
reservoir
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Figure 5.1: HEP Arrangements on the Arun River
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Key Tributary Projects
Key tributaries for this CIA include the Ikhuwa Khola and the Barun Khola. Planned HEPs on these
tributaries include IKHPP, Upper Ikhuwa Khola Small HEP, and Lower Barun HEP. A summary of the
salient features for these HEPs is provided in Table 5.2.
Ikhuwa Khola Hydropower Project
The proposed Ikhuwa Khola (IKHPP) site is located on a tributary of the Arun River approximately 8 km
downstream from the proposed UAHEP powerhouse site, and 5 km upstream from the proposed Arun
III Hydropower Project headworks. The RoR IKHPP project area is situated within longitude 87°21‟16”
to 87°25‟07” east and latitude 27°35‟07” to 27°37‟12” north.
Based on the September 2019 IKHPP Feasibility Study, the proposed IKHPP dam (6-meters high) is
located in Makalu Rural Municipality, about 588 m upstream from Ikhuwa Khola confluence with Pawa
Khola. The powerhouse site is located on the right bank of the Ikhuwa Khola near the confluence of
Arun River and Ikhuwa Khola. The diversion dam diverts a design capacity of up to 6.02 cubic meters
per second (m3/s) of water via a headrace tunnel to a powerhouse with a 40 MW capacity, returning the
water to the Arun River through a tailrace canal.
Upper Ikhuwa Khola Small HEP
According to the DoED’s hydropower license database 3, Khadga Bdr Karkee acquired a survey license
for the 9.60 MW Upper Ikhuwa Khola Small HEP. The project area is situated within longitude 87°25‟08”
to 87°27‟07” east and latitude 27°35‟50” to 27°37‟20” north. Additional information on this project is not
currently available.
Lower Barun HEP
Ampik Energy Pvt Ltd has acquired a survey license for the 132 MW RoR Lower Barun HEP on the
Barun River. An EIA has been submitted to the DoED for this project, which has not been made
available to the CIA team. Based on the develo per’s salient features document, a weir (with a crest
level of 20 m) will be built at Saldim-Barun confluence. An underground powerhouse will be built in
Bhotkhola Rural Municipality.
Isuwa Khola HEP
KBNR Isuwa Power Ltd. Is constructing this project in Isuwa river with installed capacity of 97.2 MW.
The project area is situated within longitude 87°11‟23” to 87°14‟30” east and latitude 27°34‟03” to
27°37‟00” north. Additional information on this project is not currently available. The company i s also
constructing another 40.1 MW Isuwa Khola PRoR Cascade HEP downstream from Isuwa Khola HEP.
Table 5.2: Select Salient Features of the Key Tributary Projects
Salient Features IKHPP Upper Ikhuwa Lower Barun
Operation RoR RoR RoR
MW 40 MW 9.60 MW 132 MW
Average flow 9.86 m3/s N/A 24.37m3/s
Design discharge 8.03 m3/s N/A 18.44 m3/s
Transmission line length 2 km N/A 20 km
Substation Arun Hub Arun Hub (assumed) Arun Hub (assumed)
Transmission line capacity 132 kV N/A 220 kV
3
https://www.doed.gov.np/license/13
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Figure 5.2: Planned HEPs in the Arun River Basin
Source: ERM 2020
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Projects on the Koshi River
As all the rivers in Nepal eventually flow towards India and join the Ganges River, developments and
water issues related to Nepal’s rivers also affect India. As such, surveying of the Koshi River and a
project report was prepared in 1946 for the Sapta Koshi High Dam Project. In 1954, India and Nepal
signed the Koshi Agreement to regulate the flow of the Koshi River and control flooding, nearly a year
later, planning of the Koshi Barrage commenced.
Koshi Barrage
Construction of the Koshi Barrage began near the Nepal/India border, approximately 56 km downstream
from the confluence of the Arun and Koshi rivers ( Figure 5.3), started in 1958 and was completed in
1962. The Koshi Barrage has a fish ladder, but it is reported to be very inefficient in terms of upstream
fish migration (Yadav and FAO undated). In 2008, the embankment of the Koshi Barrage collapsed and
displaced millions of people in Nepal and India. According to Oza (2014), this was the eighth major
breach since the embankment was completed in 1959. Following the 2008 breach, a Nepal-India
Commission on Water Resources issued a new strategy to control flooding on the Koshi River, which
involved restarting planning of the Sapta Koshi High Dam Project through the creation of the Sapta
Koshi Joint Commission Office.
Sapta Koshi High Dam Multipurpose Project
The Sapta Koshi High Dam Multipurpose Project (also called the Sapta Koshi Project), for which
investigations works have been underway since 2004, is currently in the Detailed Project Report (DPR)
stage. The 269 m high storage dam is planned to be situated across the Sapta Koshi, with the intended
purpose to: regulate seasonal river flows; generate hydropower with an installed capacity of 3,000 MW;
and provide flood and silt control, and irrigation to the Terai area of Nepal and North Bihar in India.
According to consultations with the Sun Koshi Sapta Koshi Investigation (SKSKI) office, the Sapta Koshi
Project is facing key challenges such as bilateral (Nepal/India) issues regarding compensation and
resettlement, public concern regarding mitigation for those displaced, and potential impacts from the
planned Tamor Storage project (located on the Tamor River upstream from the confluence with the
Sapta Koshi River). The Sapta Koshi Project dam height will need to be considered in coordination with
the Tamor Storage project. An EIA for the Sapta Koshi Project will be conducted after the project
components have been confirmed and the Detailed Feasibility Study is completed.
Although the Sapta Koshi Project is not located in the Arun River Basin, it is likely to result in backwater
effects on the Arun River (as well as the Tamor and Sun Koshi rivers). Rai (2020) reported that the
Sapta Koshi Multipurpose Project would inundate more than 11,777 ha of upstream land, and displace
10,263 people across Bhojpur, Dhankuta, and Sankhuwasabha districts ( Figure 5.4).
Figure 5.3: Schematic Diagram of the Sapta Koshi Project
Source: SKSKI, Sapta Koshi High Dam Multipurpose Brochure
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Figure 5.4: Location of the Koshi Barrage and Sapta Koshi High Dam
Source: ERM 2020
Note: The shaded areas represent the municipalities which are likely to be at least partially inundated by the Sapta Koshi
High Dam Multipurpose Project according to Rai (2020).
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Table 5.3: Hydropower Projects in the Arun River Basin
Status Hydropower Projects Capacity (MW) Promoter
Operating 9 52.865
Piluwa Khola 3.00 Arun Valley Hydropower
(operation date: 18 September 2003) Development Company Pvt.
Ltd.
Hewa Khola 4.45 Barun Hydropower
(operation date: 08 February 2002) Development Co. Pvt. Ltd
Sabha Khola 3.30 Dibyaswari Hydropower P
(commercial operation date: 20 September 2017) Ltd
Pikhuwa Khola 5.00 Eastern Hydropower P Ltd
Lower Piluwa 0.99 Baneshwor Hydropower P
Ltd
Maya Khola Hydropower Project 14.9 Maya Khola Hydropower
Company Pvt Ltd
Taksar Pikhuwa 8 Taksar Pikhuwa Khola
Hydropower Pvt Ltd
Upper Hewa HPP 8.5 Upper Hewa Khola
Hydropower Company Pvt
Ltd
Upper Pilwa Khola – 2 SHP 4.72 Menchhiyam Hydropower P
Ltd.
Under Construction 22 1,267.24
Arun-3 (construction began in 2018) 900.00 SJVN Arun-3 Power
Development Company
(SAPDC)
Chujung Khola HEP 48
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Status Hydropower Projects Capacity (MW) Promoter
Down Piluwa 10.3
Irkhuwa Khola-B HPP 15.524
Isuwa Khola Hydropower Project 97.2
Isuwa Khola PRoR Cascade HEP 37.7
Kasuwa Khola HPP 45
Lankhuwa Khola 5
Lower Chirkhuwa 4.06
Lower Hewa Khola-A HPP 7.3
Lower Irkhuwa Khola 14.15
Phedi Khola (Thumlung) Small HPP 3.52
Sabha Khola A 10.4
Sabha Khola-B HPP 15.1
Shyam Khola HEP 7.25
Super Hewa HPP 5
Upper Chirkuwa Khola 4.7
Upper Irkhuwa HPP 14.5
Upper Pikhuwa Khola HEP 4.9
Upper Piluwa 3 HPP 4.95
Upper Piluwa Hills Small HPP 4.99
Upper Piluwa-1 HEP 7.7
12 821.5
Applied for Construction License
Apsuwa I HEP 23 Ram Janaki Hydropower Pvt.
Ltd
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Status Hydropower Projects Capacity (MW) Promoter
Ikhuwa Khola HEP 40 Upper Arun Hydro Electric
Limited
Irkhuwa Khola Ka HEP 15 Eastern Hydropower Pvt.Ltd.
Kimathanka Arun HEP 454 Vidhyut Utpadan Company
Limited
Lower Apsuwa HEP 54 Mizu Energy Limited
Lower Barun Khola HPP 132 Ampik Energy Pvt Ltd
Pikhuwa Pashupati HEP 4.1 Sumnima Hydropower
Company Pvt. Ltd.
Sabha Khola C HEP (Cascade) 6.3 Orbit Energy Private Limited
Sisuwa Khola HEP 13.5 Matribhumi Hydropower
Development Company Pvt.
Ltd
Super Sabha Khola Small HEP 4.1 Sankhuwasabha Power
Development Pvt.Ltd
Upper Apsuwa HEP 35.15 Ram Janaki Hydropower Pvt.
Ltd
Upper Sankhuwa Khola HEP 40 Happy Energy Pvt. Ltd
Planned (Issued Survey License) 17 2,713.74
Arun 4 PRoR HEP 490.2 Nepal Electricity Authority
Bakan Khola HEP 44 Summit Energy Solution Pvt.
Ltd
Induwa Khola PRoR HEP 24.921 Vision Tesla Power Pvt. Ltd.
Isuwa Cascade-3 9.95 Magic Arun Hydropower
P.Ltd.
Isuwa PROR Cascade-2 HEP 9.95 Bista Energy House Pvt. Ltd.
Lower Arun Hydropower Project 679 SJVN Limited India
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Status Hydropower Projects Capacity (MW) Promoter
Mathillo Maya Khola Hydropower Project 5 Waleng Tumhok Hydro
Power Pvt. Ltd.
Pikhuwa Khola HPP 6.7 Aspire Power Company Pvt.
Ltd.
Saldim Khola HEP 45 Ludhiana Holding Energy
Nepal Pvt. Ltd
Sankhuwa Khola HEP 41.061 Guras Hydro Pvt. Ltd
Super Irkhuwa Khola HEP 5 Bhojpur Siwalaya Power Pvt.
Ltd
Super Sabha Khola A HPP 9.55 Sankhuwa Sabha
Development Pvt. Ltd.
Tejo Thogam Khola HPP 29 Snowfall Hydropower Pvt.
Ltd.
Upper Arun HEP 1,063.36 Upper Arun Hydro Electric
Limited
Upper Barunkhola HEP 109.5 Great Hydropower Pvt. Ltd
Upper Chhujung HEP 40.7 White Flower Company Pvt.
Ltd
Upper Ikhuwa Khola Hydropower Project 9.6 Sashi Power Investment Pvt.
Ltd.
Total 39 3,739.73
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Electricity Connectivity
The lack of a North-to-South high voltage transmission line has been a limiting factor for hydropower
development in the Arun River Basin. As such, networks of transmission lines are currently under-
construction or proposed. Existing and under construction transmission lines in the eastern districts of
Nepal (according to the NEA’s Power Development Map of Nepal dated July 2019; NEA 2019) are
shown in Figure 5.5.
Rastriya Prasaran Grid Co Ltd (RPGCL), which was established by the Government of Nepal in 2015
to transmit and evacuate the power for the development and operation of the hydropower sector, has
also proposed future transmission line in the Arun River Basin region in the 2018 Transmission System
Development Plan of Nepal. The RPGCL proposed transmission lines include:
◼ Around 6 km transmission line from Upper Arun substation of Sankhuwasabha district to Arun Hub
(Haitar) substation of Sankhuwasabha district is proposed to evacuate power from Upper Arun
Region.
◼ Around 35 km of Quad Moose 400kV double circuit transmission line is proposed between Arun
Hub and Sitalpati substation in Sankhuwasabha.4
◼ Around 94 km of Quad Moose 400kV double circuit transmission line is proposed between Sitalpati
substation to the Inaruwa substation, which is currently being studied by NEA (NEA 2023).
◼ Around 75 km of Quad Moose 400kV double circuit transmission line connecting Sitalpati
substation to Tingla substation; the line will then be extended from Tingla substation to Dudhkoshi
hydropower plant and Dhalkebar substation.
Hydropower projects will require construction of transmission lines to evacuate the electricity generated
to the electricity grid. Below is a summary of the transmission lines that would be constructed for select
HEPs (according to the HEP’s EIA/IEE):
◼ Kimathanka Arun: A 18.5 km long, 400 kV double circuit transmission line within a 46 m wide right-
of-way (RoW) to the proposed Arun Hub substation or a 72 km transmission line to Inaruwa
substation
◼ UAHEP: A 5.9 km long, 400 kV double circuit transmission line within a 46 m wide5 RoW extending
from the UAHEP potyard to the proposed Arun Hub substation at Hitar
◼ IKHPP: A 2.6 km long, 132kV single circuit transmission line with an 18m RoW to the Arun Hub
substation
◼ Arun-4: A 14 km long, 400 kV double circuit transmission line within a 46 m wide RoW to the Arun
Hub substation
◼ Arun-3: A 310 km long, 400 kV double circuit transmission line within a 46 m wide RoW to
Mujaffarpu, India. Only 25 km of the route is situated in the Arun Basin
◼ Lower Arun: A 2 km long, 400 kV transmission line within a 46 m wide RoW connecting to 400 kV
line emerging from Arun 3 HEP substation
4
https://rpgcl.com/projects/haitar-sitalpati-arun-corridor-400kv-transmission-line-project
5
The RoW is the area of land that will be used to locate, construct, operate, and maintain the transmission line. Most structures
and certain activities are restricted within the RoW to ensure there will be no future incompatible development that will affect
transmission line operations and to protect local residents from any adverse health effects from electric and magnetic fields.
The standard RoW width for a 400 kV transmission line in Nepal is 46 meters, 23 meters horizontally on each side from the
centerline. The transmission line towers will be located along the centerline of the RoW. In Nepal, typically just the land
underlying the towers is acquired, while private owners of other land within the RoW receive compensation for the restrictions
placed on their land.
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Figure 5.5: Power Development Plan in Eastern Nepal
Source: Power Development Map of Nepal (NEA 2019)
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Access Roads
Access roads are needed for HEPs to transport required structures and materials during construction
and operation. Hydropower projects in the Arun River Basin will typically require either extensions or
improvements and the widening of existing roads. For example, below is a description of the access
roads which would be required for construction/operation of the following HEPs (according to the HEP’s
EIA/IEE):
◼ Upper Arun HEP – Requires completion of the Koshi Highway and building of a dedicated access
road of approximately 22 km, including an estimated 2.0 km of road tunnel and a bridge over the
Arun River
◼ Arun-4 HEP – Requires a 23 km extension from the existing road network
◼ Ikhuwa Khola HPP – Requires an extension of 4 km to connect the powerhouse to the Koshi Road;
an additional of 12.5 km of hilly road will be constructed from the powerhouse site to the headwork
◼ Arun-3-HEP – A total of 88 km of road network needs to be constructed for the proposed project.
An IEE has been approved for a stretch of 58.51 km roads and these segments are under
construction. The remaining stretch of about 29.09 km will be constructed as a part of Arun-3 HEP.
◼ Lower Arun – The existing earthen road Tumlingtar-Khandbari-Kheutar would be extended and
upgraded for the access to the dam site. For the access to Powerhouse, the existing Tumlingtar-
Betini/Chewabesi road is to be upgraded.
In addition to the HEPs, temporary roads may be constructed for access to tower locations during
construction of transmission lines in this region.
5.3.2 Road Infrastructure
The Koshi Hills comprises four districts; Sankhuwasabha, Bhojpur, Dhankuta and Terhathum, all
belonging to the eastern region of Nepal. The first roads in Koshi Hills were constructed in 1982, by
2007 all four districts headquarters were connected to the road network totaling 934 km. The Koshi
Highway, also known as the Dharan-Dhankuta Highway, is the main thoroughfare that connects the
Koshi Hills with the Terai region and other major places across the country, as well as the bordering
cities of India. Shown in Figure 5.6 is the existing road infrastructure in the Arun River Basin.
There has been a drastic change in road networks in the Koshi Hills over the past 24 years. The average
road density was 14.2/100 km2 in 2010, increasing from the density below 9.1/100 km2 in 2007. Bhojpur
and Sankhuwasabha have a relatively poor road density, below 7.7/100 km 2. However, these two
districts are linked by an air service with Kathmandu (national capital city) and Biratnagar (regional city
in the eastern Terai region). In areas of Koshi Hills where there are no roads, traditional highways such
as trail networks and bridges are crucial. There are about 1,093 km of trails and 231 trail bridges in the
Koshi Hills region (Pradhan and Sharma 2017).
The North-South Highway (Koshi Highway) connects India to China across the Himalayan Mountains
in Nepal.6 The Tumlingtar-Khandbari road was built in 2010, the Khandbari-Num road was completed
in 2016, and the track beyond Num was recently opened in 2018 as a part of the Koshi Highway (Figure
5.7) and is in the process of being completed. According to the North-South Highway Project Office,
approximately 14 km remains to be completed from Chemtang to Ghongghappa, which is expected to
be opened in 2022. This section of the Koshi Highway is still not completed.
The 1,776 km Mid Hill Highway is under construction to connect east and west Nepal. As shown in
Figure 5.8., a portion of the highway passes through the Arun Basin. An EIA has been undertaken for
the Mid Hill Highway, which was not available to the CIA Team.
Cumulative impacts of the existing road network and the remaining sections of the Koshi Highway to
the selected VECs are assessed in Section 8.
6
https://thehimalayantimes.com/nepal/biratnagar-kimathanka-trilateral-road-projects-disheartening-progress/
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Figure 5.6: Road Infrastructure in the Arun River Basin
Source: Pradhan & Sharma 2017
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Figure 5.7: North-South Highway (Khandbari-Kimathanka)
Source: Num-Kimathanka EIA 2019
Figure 5.8: Schematic of the Mid Hill Highway
Source: Phidim District Department of Roads
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5.3.3 Agriculture
Agriculture has been the predominant economic activity in the Koshi Hills (Sankhuwasabha, Bhojpur,
Dhankuta, and Terhathum districts), although the population engaged in this sector has decreased from
98% in 1971 to 76% in 2001, which was still far higher than the national average (60% in 2001). The
agricultural system is predominantly subsistence in nature, except in few areas accessed by roads
where intensive cultivation of vegetables is practiced (Pradhan and Sharma 2017). The development
of roads in the region since 1985 has encouraged the substantial increase of commercial farming,
however, between 1995 and 2011, changes in commercial agriculture were detected. Changes were
observed in the growth in production of high value crops and commercial utilization of forest products.
Vegetable production has increased from negligible amounts cultivated for home consumption in the
1970s to over 101,000 metric tons (MT) by 2009/10 (MoAC 2010). Production and cropping areas have
risen significantly from 1990 onwards, with cultivation mostly concentrated in Dhankuta, which produced
46% of total vegetables in the region, followed by Terhathum (19%), Bhojpur (18%), and
Sankhuwasabha (17%).
Agricultural production has largely been along the road corridors and near the main bazaars and/or
towns. Large cardamom production has dramatically increased from seven hectares in 1971 to 3,930
hectares in 2009 (representing a 561-fold increase) (MoAC 2010). In 2009/10, the four districts
produced 1,603 MT of the spice (31% of nationwide production), with Sankhuwasabha becoming the
third largest producer in the country. Households can earn NPR 60,000 to 90,000 from cardamom
cultivation in one season.7
The main types of agricultural areas in the basin Ide bari (upland irrigated), khet (riverine), pakho
(unirrigated), and floodplain agriculture. Typically, agricultural land closer to the river is given to land
users under three types of land tenure arrangements: adhiya or sharecropping (predominant upstream
and downstream); bandhagi or convenience-based use, collateral linked to loan repayment
(predominant midstream); and kut farming or contract farming (predominant midstream). Paddy is
generally grown in khet and maize and millet in bari land. Similarly, cardamom is grown in pakho and
bari land (Arun-3 EIA).
In line with the CIA consultations with the Water Source and Divisional Irrigation Office and downstream
local communities, common agricultural products include paddy, millet, vegetables, maize, wheat, and
cash crops (cardamom, chilli, mushroom, etc.). Most farming activities are for household consumption
and for sale in the local markets. Few farmers are engaged in large-scale commercial agriculture
according to consultation with the Agriculture Knowledge Centre.
5.3.4 Sand and Gravel Extraction
The CIA Downstream Consultations indicate that most gravel, sand and stone are extracted from Shaba
Khola, Sishwa Khola, and Nepa Khola and partly from the Arun River. The extracted materials are
typically used within the district, for instance, for road construction. This is particularly the case for the
North-South Highway, which sources gravel, sand and stones from streams along the road alignment.
Crusher plants are not allowed in the Arun River, however, small scale mining for households and other
purposes is seen at some locations along the Arun River.
If practiced unsustainably, sand and gravel extraction could increase riverbank erosion and result in
negative hydrological and biodiversity impacts. As such, the impacts of sand and gravel extraction
activities are considered for selected VECs. Additionally, given that sand and gravel extraction is a
livelihood source in the Arun River Basin, cumulative impacts on this income generating activity are
considered under VEC: river-based livelihoods.
7
https://assets.publishing.service.gov.uk/media/57a08a2540f0b652dd0005ae/NPRKH_Final_Summary_Report.pdf
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5.3.5 Mining
Shown in Figure 5.9 is the only known mining site (Lulu Sb) in the TAR portion of Arun River Basin.
This quartz mine is located over 100 km north of the Nepal/TAR border.
Figure 5.9: Mining Site in the Arun Basin
Source: ERM 2020
5.3.6 Natural Hazards and Climate Risks
Nepal is among the 20 most disaster-prone countries in the world, in terms of both natural and human
induced disasters (MoHA 2017). Globally, Nepal ranks 4th and 11th in terms of its relative vulnerability
to climate change and earthquakes, respectively (MoHA 2015). More than 80% of the total population
of Nepal is at risk of natural hazards such as floods, landslides, windstorms, hailstorms, fires,
earthquakes and glacial lake outburst floods (GLOFs). These natural hazard and climate risks have
been exacerbated by the warming of the climate. Over the last 30 years, Nepal has experienced an
0.06°C temperature increase, which is higher than the global rate, and has resulted in rapid shrinking
of the majority of glaciers in Nepal (Shrestha and Aryal 2011).
The Government of Nepal conducted a climate change vulnerability mapping in 2010. Vulnerability is
mapped through different natural hazard indicators like rainfall and temperature vulnerability index,
landslide vulnerability index, flood vulnerability index, drought vulnerability index, GLOF vulnerability
index, and overall index. Shown in Table 5.4 are the findings of climate vulnerability index for districts
in the Arun River Basin. Overall, Sankhuwasabha and Bhojpur districts are ranked as ‘high’ vulnerabi lity
and Dhankuta is ranked as ‘moderate’.
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Table 5.4: Vulnerability Index for Districts in the Arun Basin
Vulnerability Vulnerability Rank
Index
Sankhuwasabha Bhojpur Dhankuta
Rainfall and Low Low High
temperature risk
Landslide Moderate High Low
Flood Very Low Very Low Very Low
Drought Very Low Moderate Very Low
GLOF Very High High High
Overall High High Moderate
Source: MoE 2010
In addition to the current situation and impacts of climate change, a significant and consistent increase
in temperature was projected for Nepal. Various models projected the warming of temperature to be
above the baseline average (1977–2000); the temperature will increase by 1.2°C in 2030, 1.7°C in 2050
and 3.0°C in 2100. These models also showed the possible impacts of climate change induced
deglaciation on various sectors, such as increase in mean river discharge, GLOFs, landslides, and their
eventual effects on agriculture and livelihoods (Agrawala et al. 2003).
The following subsections provide additional details regarding floods, landslides, GLOFs and
earthquakes in the Arun River Basin. The impacts of these natural hazards to the selected VECs are
also considered in Section 8: Cumulative Impact Assessment.
Floods
The Koshi River is termed the “sorrow of Bihar”, as frequent floods kill hundreds of people and affect
thousands of hectares of agricultural land on an annual basis. The Himalayan foothills in the Arun Basin
are subject to intense and prolonged rainfall during summer, which produces locally-high river levels
and contributes to downstream flooding. Flood-generating overland flow has even been observed in the
cloud forests of the upper Arun. The greatest peak flows in the Himalaya tend to result from sudden
releases of water following failure of some natural impoundment. Such dams include glaciers, glacial
moraines, and mass movement deposits. Several million m 3 of water may enter the river in just a few
hours. Such floods, where they occur, far exceed peak flows resulting from rainfall or snow- and ice-
melt in upstream areas. Even though these flash floods are attenuated downstream, the potential for
destruction from dense debris flows is likely to be far above that caused by rainfall floods (Kattelmann
1990). Table 5.5 shows impact of floods and landslides in districts of the Arun Basin during the period
2000 to 2009.
Table 5.5: Impact of Floods and Landslides in the Study Districts (2000–2009)
District Deaths Affected Families Animal Loss
Bhojpur 23 504 238
Dhankuta 12 74 28
Sankhuwasabha 31 391 482
Source: (Samir 2013)
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Bharati (2019) found that climate change will mean a high likelihood of wetter and stronger monsoons
in the future, which will increase risks for monsoon-related disasters, such as landslides and floods.
Based on statistical analysis and modelling of climate change impacts on the whole Koshi River Basin,
Prasad and Gyawali (2015) also found that annual water discharge will increase due to climate change,
particularly during the monsoon season, which could lead to more flood events.
Prasad and Gyawali (2015) found that snow and glacier melt currently contribute approximately 34% of
annual discharges in the Koshi River Basin, and that climate change will induce the melting of glaciers
and snow in the surrounding area, thus contributing to a 13% increase in annual discharges by 2050.
Glacial Lake Outburst Floods (GLOFs)
According to (ICIMOD 2011) one of the more spectacular effects of recent atmospheric warming in the
Himalayas is the creation of meltwater lakes on the lower sections of many glaciers. Glacier are
retreating quickly in Nepal – ranging from 3 to 6 meters per year (Shrestha and Shrestha 2004) – and
are projected to continue or accelerate due to global warming (Agrawal 2008; ICIMOD 2011).
The most active glaciers in Nepal and the adjoining region of Tibet Autonomous Region in China are
located in the eastern part of the region. In the Arun Basin, Washakh et al. (2019) identified 49 glacial
lakes with areas greater than 0.1 km2 (Figure 5.10). These lakes can be potentially hazardous in the
event that a GLOF occurs, which suddenly releases the stored water. GLOFs are one of the major
natural hazards in Nepal, particularly in Sankhuwasabha District. Since 1964, 10 of the 11 major natural
hazards recorded in the Arun River were due to GLOFs (Table 5.6). These flood surges can potentially
destroy infrastructure and take human lives in the valleys below.
Washakh et al. (2019) identified four potentially critical glacial lakes (nos. 20, 35, 36, and 49, Figure
5.10) for the UAHEP powerhouse. Glacial lake no. 49 (Langmale Lake) is located in the Arun Basin,
specifically, on the Barun River in the MBNP. On April 20, 2017, a flood from the Barun River formed a
2–3-km-long, 500-m-wide lake at its confluence with the Arun River. Debris had dammed the
floodwaters directly above the village of Barun Bazaar, which displaced 10 families from their homes,
destroyed fields, and threatened to impact at least 80 families living within the immediate area in the
event that the dam suddenly failed The lake also threatened downstream villages, including Phaksinda,
Diding, Chetabesi, Lumningtar, and other riverside communities in Bhojpur and Dhankuta districts, as
well as UAHEP construction activities, located two km downstream (Byers et al. 2019).
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Figure 5.10: Glacial Lakes in the Arun Basin
Source: Washakh et al. 2019
Table 5.6: Recorded Natural Hazards in the Arun River
SN Flood in Arun River Cause of floods Effects on Infrastructures and Lives
1. 21 September 1964 Gelhaipo lake outburst in TAR; Damaged road, 12 trucks, etc.
end moraine collapse due to
glacier-fall into lake
2. Around 1964 GLOF noticed by local people Timber, concrete block, and parts of
along the Arun River trucks flowing down
3. NA GLOF along the Barun Khola.
Some traces of past GLOF on
the river channel recognized
from aerial survey
4 1968 Ayico lake outburst, TAR Damaged road and bridge, etc.
5. 1969 Ayico lake outburst, TAR Damaged road and bridge, etc.
6. 1970 Ayico lake outburst, TAR Damaged road and bridge, etc.
7. October 2–6, 1979 Large rainfall in upper Arun Not stated
Basin and Num
8. August 27, 1982 Jinco lake outburst, TAR Not stated
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SN Flood in Arun River Cause of floods Effects on Infrastructures and Lives
9. August 27, 1985 Jinco lake outburst, TAR Damaged eight villages, livestock, farm
land, roads, bridges, etc.
10. April 20, 2017 Langmale glacier lake flood and 9 houses inundated by the flood,
flood debris deposited by destroyed dozens of hectares of pasture
tributary Barun River at and forest land, killed 24 yaks and dzo
Bhotkhola
11. June 22, 2019 Landslides and floods due heavy Excavator, loader, tractor, truck, and
rainfall compressor and more than 200 quintals
of iron rod were swept away; property
worth 400 million NPR in Phyaksinda
Source: Yamada and Sharma 1993; Shrestha and Shrestha 2004; Chen et al. 2013; Byers et al. 2019; Himalayan
Times 2017
Landslides
The geological characteristics of the Himalayan mountains make them highly vulnerable to landslides
and other mass wasting processes from factors such as rainfall, earthquakes, floods, road construction
and development works. Nepal suffers from numerous landslides, especially during the late monsoon
period when water pressure builds up in the hill-slope mass or catastrophic earthquake happens (Thapa
2015).
The devastating 2015 earthquake event and its subsequent aftershocks caused over 3,000 landslides
across Nepal, including in the Koshi River Basin (ICIMOD 2016). 8 Impacts from landslides include
alteration of water height and flow regimes, therefore, affecting the potential for hydropower projects to
generate power. There is a risk that alterations are not within the design capacity of a dam’s structural
integrity, which can lead to the cracking of dam structures or even to dam collapse.
The Eastern region of Nepal accounts for 19% of the total fatalities caused by landslides in Nepal.
Available landslide and related hazards database (DesInventar) during the period from 1971 to 2013
shows that average loss of life is about 24 per year in the region. The districts with high occurrence of
landslides in the eastern Nepal are Taplejung, Panchthar, Ilam , Sankhuwasabha, Solukhumbu,
Okhaldhunga, and Khotang. The region has significantly high reports of human deaths and other losses,
such as buildings destroyed and damaged, because of landslides with high impact in Okhaldhunga
(1976), Jhapa (1980), Dhankuta (1987), and Khotang (2002) etc. The high number of affected people
in Bhojpur (1996), Sankhuwasabha (2008), Sankhuwasabha (2011) and Terhathum (2011) can be
traced Ihe occurrence of severe landslides. The districts with extremely high economic losses are
Khotang, Taplejung, Okhaldhunga, and Sankhuwasabha (Chaydhary et al. 2015).
Kumar (2020) examined landslide and erosion hotspots within the lower Arun Basin. The study found
103 landslide hotspots (Figure 5.11) and explained that characteristics of landslide distribution strongly
correlate with slope, land use and land cover and presences of stream and its spatial density.
8
http://lib.icimod.org/record/31841/files/River_Basin_management.pdf
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UAHEP CUMULATIVE IMPACT ASSESSMENT SCOPE OF CUMULATIVE IMPACT ASSESSMENT
Figure 5.11: Landslide Hotspots in the Lower Arun Basin
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UAHEP CUMULATIVE IMPACT ASSESSMENT SCOPE OF CUMULATIVE IMPACT ASSESSMENT
Earthquakes
Shown in Table 5.7 are the recorded earthquakes in the Arun River Basin, according to the Nepal
National Seismological Centre website. According to the data, there have been at least 22 light-
moderate intensity earthquakes between 1994 and 2018, ranging from a 4.0 to 5.3 magnitude (ML),
and no records of strong intensity (above 6.0 ML) of earthquakes in this region.
Table 5.7: Earthquakes Recorded in the Arun River Basin between 1994 and 2018
Date Time Latitude Longitude Magnitude (ML) Epicenter
A.D:2018-08-29 Local:23:35 27.79 87.41 4.2 Sankhuwasabha
A.D:2016-02-23 Local:08:45 27.47 87.15 4.5 Sankhuwasabha
A.D:2013-10-28 Local:07:22 27.36 87.37 4.3 Sankhuwasabha
A.D:2011-06-18 Local:11:00 27.83 87.35 4.3 Sankhuwasabha
A.D:2011-02-22 Local:11:00 27.57 87.01 4.2 Sankhuwasabha
A.D:2011-02-13 Local:11:00 27.47 87.01 4.7 Bhojpur-Sankhuwasabha border
A.D:2009-05-14 Local:11:00 27.48 87.36 4.6 Sankhuwasabha
A.D:2009-05-14 Local:11:00 27.43 87.35 4.2 Sankhuwasabha
A.D:2005-08-28 Local:11:00 27.31 87.22 5.3 Sankhuwasabha
A.D:2002-07-16 Local:11:00 27.75 87.36 4.3 Sankhuwasabha
A.D:2000-03-17 Local:11:00 27.76 87.55 4.2 Sankhuwasabha
A.D:2000-03-13 Local:11:00 27.73 87.71 5.1 Sankhuwasabha
A.D:1998-06-27 Local:11:00 27.866 85.812 5 Sankhuwasabha
A.D:1994-09-25 Local:11:00 28.34 87.35 4.8 Sankhuwasabha
A.D:2007-07-30 Local:11:00 27.27 87.02 4.1 Bhojpur
A.D:2015-02-14 Local:01:37 28.85 82.18 5.1 Bhojpur
A.D:2007-08-03 Local:11:00 27.24 87.03 4.5 Bhojpur
A.D:2007-08-03 Local:11:00 27.2 87.04 4.3 Bhojpur
A.D:2007-08-03 Local:11:00 27.24 87.02 4 Bhojpur
A.D:2007-07-30 Local:11:00 27.27 87.02 4.1 Bhojpur
A.D:2013-09-12 Local:10:14 26.96 87.34 4.5 Dhankuta
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UAHEP CUMULATIVE IMPACT ASSESSMENT VEC SCREENING AND SELECTION
6. VEC SCREENING AND SELECTION
Valued environmental, social, and ecosystem components (VECs) are defined as fundamental
elements of the physical, biological or socio-economic environment that are likely to be the most
sensitive receptors to the cumulative impacts of other projects and stressors in combination with the
proposed project.
A set of preliminary VECs were identified through stakeholder engagement, as summarized in Section
2.2.2. A VEC screening process was conducted to determine which of the preliminary VECs would be
included in the CIA. As shown in Figure 6.1, to be selected for this the CIA, a VEC must first be
confirmed to be valued by an identifiable stakeholder group and/or the scientific community. Second,
the VEC must be reasonably expected to be affected by some combination of other projects and/or
external stressors. Findings from the VEC screening process are presented in Table 6.1, and the
selected VECs and assessment approach are summarized in Table 6.2.
Figure 6.1: VEC screening process
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UAHEP CUMULATIVE IMPACT ASSESSMENT VEC SCREENING AND SELECTION
Table 6.1: VEC Screening and Selection
Impacted by
Valued by Impacted by Other
Potential VEC Selected for CIA Justification, Comments
Stakeholders UAHEP Projects and
Stressors
Air quality Yes, according Yes No potential No This VEC has not been selected for the CIA because there is
to consultations for cumulative negligible potential for significant cumulative air quality impacts
impacts (e.g., from fugitive dust) from HEP developments, as the
impact from a HEP on air quality is temporary and unlikely to
extend far enough to result in cumulative impacts with other
source of air emissions.
Noise Yes, according Yes No potential No This VEC has not been selected for the CIA because there is
to consultations for cumulative negligible potential for significant cumulative noise impacts
impacts from HEP developments. Noise impacts from HEPs are
typically temporary, limited to the construction phase.
Water resources Yes, according Yes Yes Yes Cumulative impacts on including water quality, geomorphology,
to consultations and sediment transport are considered in this CIA.
Natural forest Yes, according Yes Yes Yes Natural forest loss and fragmentation from hydropower projects,
integrity to consultations other developments, and climate change-related risks are
considered in this CIA. In addition, natural forests serve as
habitats for several important species, therefore, assessing the
impacts on natural forest is an indicator for impacts on diversity
of species.
Makalu Barun Yes, according Yes Yes Yes Impact to critical terrestrial species and habitat in the MBNP from
National Park to consultations hydropower projects and other developments (particularly
roads) are considered in this CIA.
Fish and aquatic Yes, according Yes, potentially Yes, Yes Cumulative impacts on fish and aquatic habitat from barrier
habitat to consultations significant potentially effects, changes in hydraulic/hydrological regimes, and climate
significant related impacts are considered in this CIA.
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UAHEP CUMULATIVE IMPACT ASSESSMENT VEC SCREENING AND SELECTION
Impacted by
Valued by Impacted by Other
Potential VEC Selected for CIA Justification, Comments
Stakeholders UAHEP Projects and
Stressors
River-based Yes, according Yes Yes Yes Cumulative impacts from hydropower projects, other
livelihoods to consultations developments and climate change, on river-based livelihoods
(i.e., irrigation, rafting and sport fishing outfitters, artisanal
fishing, and river mining are considered in this CIA.
Settlement Yes, according Yes Yes Yes Cumulative impacts from hydropower projects, other
to consultations developments and climate change, on settlement patterns and
associated effects are considered in this CIA.
Social cohesion Yes, according Yes Yes Yes Cumulative impacts from hydropower projects, other
to consultations developments (including roads) and climate change, on social
cohesion components are considered in this CIA.
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UAHEP CUMULATIVE IMPACT ASSESSMENT VEC SCREENING AND SELECTION
Using the results of stakeholder consultations, field surveys, data analysis, and the literature review, the
following seven VECs were selected for the CIA study: natural forest integrity, Makalu Barun National Park,
water resources, fish and aquatic habitat, river-based livelihoods, settlement, and social cohesion. The key
basin-level impacts and CIA assessment approach for each of selected VECs are summarized in Table 6.2.
The following sections of this CIA study will present the baseline status, potential cumulative impacts,
and mitigation and monitoring framework to manage impacts on the selected VECs.
Table 6.2: Final VECs and Assessment Approach
VEC Key Basin-level Impacts to Consider Assessment Metrics
Physical Components
Forest loss and fragmentation from ◼ Forest land gain/transfer
VEC: Natural hydropower projects, other ◼ Loss of ecosystem
forest integrity developments, and climate change- services values from forest
related risks clearance
Changes to the physical characteristics ◼ Qualitative assessment of
VEC: Water of a river, including water quality, the level of impact to water
resources geomorphology, and sediment quality and flow
transport
Biological Componets
Barrier effects (fragmentation) and ◼ Seven native species
VEC: Fish and changes in flows that lead to including golden mahseer
aquatic habitat degradation of ecosystem integrity and and common snow trout
fish habitat used at indicators
◼ River segments subject to
flow alterations
◼ Aquatic habitat
fragmentation and losses
Impact on critical terrestrial species and ◼ Forest land gain/transfer
VEC: Makalu habitat in the MBNP from hydropower ◼ Loss of ecosystem
Barun National projects and other developments services values from forest
Park (particularly roads) clearance
Social Components
Impact of hydropower projects, other Qualitative assessment of the
VEC: River-based developments, and climate change, on level of impact to the livelihood
livelihoods sources of livelihoods, including: components
◼ Irrigation
◼ Rafting and sport fishing outfitters
◼ Artisanal fishing
◼ River mining
VEC: Settlement Impact of hydropower projects, other Qualitative assessment of the
developments, and climate change on level of impact resulting from
settlement patterns and associated changes in settlement patterns
effects such as:
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UAHEP CUMULATIVE IMPACT ASSESSMENT VEC SCREENING AND SELECTION
VEC Key Basin-level Impacts to Consider Assessment Metrics
◼ Changes in settlement
demographics resulting in possible
conflict
◼ Changes in intangible cultural
heritage resources resulting from
changes in settlement
demographics
Impact from hydropower projects, other Qualitative assessment of the
VEC: Social developments (including roads), and level of impact on the
cohesion climate change, on social cohesion components of social cohesion
components:
◼ Social safety nets
◼ Gender and social exclusion
◼ Social tension
◼ Access to culturally significant
places/practices
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UAHEP CUMULATIVE IMPACT ASSESSMENT BASELINE STATUS OF SELECTED VECS
7. BASELINE STATUS OF SELECTED VECS
7.1 VEC: Natural Forest Integrity
Natural forest integrity was selected as a VEC for this CIA considering the importance of forested land
to communities, biodiversity, and ecological processes and ecosystem services. Moreover, the
cumulative impacts of hydropower projects, road developments (specifically the Koshi Highway), and
climate change to forest lands may be significant over the 10 years.
7.1.1 Types of Forests in the Arun Basin
The forest of eastern Nepal is categorized into eight broad types (Stainton 1972). Table 7.1 describes
these forest types.
Table 7.1: Forest Types within Eastern Nepal
Forest Type Elevation
Tropical forests <1,000 m
Sub-tropical broadleaved forest 1,000–2,000 m
Sub-tropical pine forest 1,000–2,200 m
Upper temperate broadleaved forest 2,200–3,000 m
Upper temperate mixed broadleaved forest 2,500–3,500 m
Temperate coniferous forest 2,000–3,000 m
Sub-alpine forest 3,000–4,100 m
Alpine scrub above 4,100 m
Source: Stainton 1972
7.1.2 Land Use/Land Cover Assessment
Historical forest land and other land use and land cover (LULC) in the Arun River Basin were analyzed9
using remote sensing to determine the dynamic change between forest land and other land covers from
year 2009 to 2018. The assessed LULC classes fall into six key categories: agricultural land, settlement
land, forest, waterbody, grassland/shrubland, barren land,10 and snow. A graphical representation of
these LULC classes within the CIA Study Area in Nepal for years 2009 and 2018 is presented in Figure
7.1.
As shown in Table 7.2 and Figure 7.1 forested areas comprised the greatest amount of land in the CIA
study area in both years, occupying almost 66% of the total basin area (5,171 km2) in 2018. Forested
land was mostly concentrated in the northern part of the CIA study area in Sankhuwasabha District.
9
Key limitations of the LULC study: 1) six broad land classes were assessed, land classes in between or a mixture of land
classes were not captured in the study; 2) LULC classification assumptions were for ambiguous Landsat satellite sensing
images – e.g., shadows and blurred LULC boundaries; 3) these findings have not been verified by field surveys or consultations
with personnel representing the districts in the study area.
10
Barren land is defined as areas covered by sand, rock (e.g., scree), in which less than one third of the area has vegetation.
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UAHEP CUMULATIVE IMPACT ASSESSMENT BASELINE STATUS OF SELECTED VECS
Figure 7.1: Arun Basin Land Cover in 2008 and 2018
2009 2018
Table 7.2: LULC Dataset
Dataset Date Resolution Azimuth Elevation Angle
Landsat 8 OLI/TRIS November 11, 30 155.59 35.09
(Path/Row:139/41,140/41) 2018
156.39 36.05
Landsat 5 TM October 15, 2009 30 152.23 37.33
(Path/Row:139/41,140/41)
152.45 35.93
Agricultural land was the second largest LULC class, covering an area of 878 km2 (17%) in 2018.
Agricultural lands were primarily located in the southern part of the basin in Bhojpur and Dhankuta
districts. In Sankhuwasabha District, agricultural land scattered along the river valley and in the lower
elevation mountains the south of the district. The remaining study area comprised grassland/shrublands
(166 km2, 3%); barren land (266 km2, 5%); settlements (116 km2, 2%); and waterbodies (17 km2, 0.3%)
in 2018.
This is mostly in line with a study of land use change in the Koshi Hills region (covering Sankhuwasabha,
Bhojpur, Dhankuta, and Terhathum districts) by Pradhan and Sharma (2017). The study found that in
2010, Sankhuwasabha and Bhojpur had a forest coverage of 51% and 46%, respectively, while
Dhankuta, and Terhathum had over 46% agricultural land coverage. Table 7.3 compares land use/land
cover in 2009 and 2018.
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Table 7.3: Proportion of LULC Classes in 2009 and 2018
2009 2018 Change from 2009 to
2018
Land Class Area (km2) Area (%) Area (km2) Area (%) Area (km2) Area (%)
Agriculture 823 16 878 17 55 6
Settlements 47 1 116 2 69 60
Snow/clouded area 361 7 322 6 -39 -12
Forest 3,376 66 3,377 66 39 <1
Grassland/shrubland 152 3 166 3 14 8
Barren land 363 7 266 5 -97 -37
Waterbodies 18 <1 17 <1 <1 -6
Total 5,141 5,141 0.00
Source: ERM 2020
Increases (gains) and decreases (losses) for each land use class between 2009 and 2018 are illustrated
in Figure 7.2. Shown in Table 7.4 is the statistical representational of the net changes in the LULC
classes between 2009 and 2018. There was a minor increase of 0.01% of forested land in the Arun
Basin. The significant gain of forest land was from the conversion of 266 km2 of agricultural land, and
67 km2 of barren land and 65 km2 of settlement land to forest land. However, 188 km2 of forest land was
lost due to conversion to agricultural land. In comparison, the Global Forest Watch 11 results for the
greater Koshi Region (Eastern Region of Nepal) found that the region has lost 0.4% of its tree coverage
between 2009 and 2018.
Agriculture land had a slight gain of 6% between 2009 and 2019 (from 823 km2 to 878 km2), as shown
in Table 7.5. It is noteworthy that the gain was particularly in the southern reach of the Arun Basin. The
settlement areas increased (60%) from 47 km2 to 116 km2 between 2009 and 2018. However,
settlements still accounted for only for 2% of the total study area in 2018.
Pradhan and Sharma (2017) support this pattern of land areas transfer in LULC classes. Their study
indicated that, during the past two decades (1986–2010), forest land appears to be increasing by
encroaching upon shrubland/grassland and agricultural land. An increase in “other land” use
(comprising waterbodies, snow land, bare land, rock and ice, built up land, and road), mainly due to
encroachment upon forest, agricultural land, and grassland, might be due to the construction of roads,
expansion of settlement clusters, and institution buildings, etc.
11
https://www.globalforestwatch.org/dashboards/country/NPL/2/1/
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UAHEP CUMULATIVE IMPACT ASSESSMENT BASELINE STATUS OF SELECTED VECS
Figure 7.2: Gains and Losses in LULC between 2009 and 2018
Gain and losses to Gain and losses to Gain and losses to
barren land agriculture land grassland/shrubland
Gain and losses to Gain and losses to Gain and losses to
forest land settlements waterbodies
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UAHEP CUMULATIVE IMPACT ASSESSMENT BASELINE STATUS OF SELECTED VECS
A summary of the land use dynamic changes in the CIA study area between 2009 and 2018 is shown
in Table 7.5. Settlement was the fastest changing land class during this period, with a rate of change
of 30 km2.a-1 (square kilometers per annum), followed by barren land at 10 km2.a-1. Settlement land also
had the highest gain rate of 22 km2.a-1, followed by waterbodies and grassland/shrubland at 5 km2.a-1
and 4 km2.a-1, respectively.
Forest underwent the lowest change between 2009 and 2018, namely, 3 km2.a-1. As discussed above,
the overall net gain in this LULC class was 0.10%. The transfer rate and gain rates were both at 1 km2.a-
1. Change rates for agriculture land were relatively modest, namely, 6 km2.a-1. The transfer rate and
gain rates were 3 km2.a-1 each. The change rate of grassland/shrubland is also considered relatively
modest (8 km2.a-1). The transfer rate and gain rates were 3.5 km2.a-1 and 4.3 km2.a-1, respectively.
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UAHEP CUMULATIVE IMPACT ASSESSMENT BASELINE STATUS OF SELECTED VECS
Table 7.4: Area Transfers in LULC Classes from 2009–2018 (km2)
2018
Land Class
Agriculture Settlements Snow/Clouded Area Forest Grassland/Shrubland Barren Land Waterbodies Total
2009 Agriculture 588 43 - 188 - 4 <1 823
Settlements 23 4 - 15 4 1 <1 47
Snow/clouded area 0.1 0.06 238 35 0.07 84 4 361
Forest 266 65 57 2,849 68 67 3 3,376
Grassland/shrubland - 3.5 - 54 94 1 0 152
Barren land 0.4 0.09 26 227 0.22 108 1 363
Waterbodies 0.04 0.11 0.08 8 0.01 1 8 18
Total 878 116 321 3,377 166 266 17 5,140
Source: ERM 2020
Table 7.5: Rate of Change in LULC Classes from 1992–2017
Land Class Unchanged Transfer Gain Rate of Dynamic
Area Change/(km2 Degree
2008 2019 Area/km2 Rate/(km2 per year) Area/km2 Rate/(km2 per year)
per year) (%)
Agriculture 588 823 878 235 2.6 289 3.2 5.8 2.6
Settlements 4 47 116 43 8.3 112 21.8 30.1 8.3
Snow/clouded area 238 361 322 123 3.1 83 2.1 5.2 3.1
Forest 2,849 3,376 3,377 527 1.4 528 1.4 2.8 1.4
Grassland/shrubland 94 152 166 59 3.5 72 4.3 7.8 3.5
Barren land 108 363 266 255 6.4 158 3.9 10.3 6.4
Waterbodies 8 18 17 10 5.1 9 4.6 9.7 5.1
Total 5,141 5,141 30.4 41.4 71.7 30.4
Source: ERM 2020
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UAHEP CUMULATIVE IMPACT ASSESSMENT BASELINE STATUS OF SELECTED VECS
7.1.3 LULC of the Arun Basin in Tibet Autonomous Region
The LULC of the portion of the Arun Basin within TAR was analyzed using remote sensing. As shown
in Table 7.6 and Figure 7.3, bare land covers approximately 61% of the 24,878 km2 area, followed by
26% of grassland/shrubland.
Table 7.6: LULC in the Arun Basin within Tibet Autonomous Region
Land Cover in the Arun Basin within TAR Area (km2) % of Total Area
Cropland 44 <1
Barren (bare) land 15,162 61
Wetlands 546 2
Forest 1,136 5
Grasslands/shrubland 6,359 26
Permanent snow/ice 1,553 6
Settlements 15 <1
Waterbodies 73 <1
Total 24,873 100
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UAHEP CUMULATIVE IMPACT ASSESSMENT BASELINE STATUS OF SELECTED VECS
Figure 7.3: LULC in the Arun Basin in Tibet Autonomous Region
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UAHEP CUMULATIVE IMPACT ASSESSMENT BASELINE STATUS OF SELECTED VECS
7.1.4 Ecosystem Services from Forests
Forest Resources
Inhabitants of the Arun Basin are highly dependent on ecosystem services from the forest. They
primarily harvest poles, fuelwood, and timber from community and private forest (ICIMOD 2012) The
incidence of poverty is high in rural areas of the Koshi Hills. Those with limited resources of their own,
locals particularly rely on community forests to sustain their livelihoods. In addition, forests also provide
employment opportunities through small scale forest enterprises.
In the Koshi Hills, nearly 1,400 community forest user groups (CFUGs) have been formed. More than
85% of total households in Sankhuwasabha, Bhojpur, Terhathum and Dhankuta districts are involved
in these CFUGs, and together they manage 82% of local forest areas. Out of the total households
involved in CFUGs, about 49% are categorized as relatively poor, based on participatory well‐being
criteria.
CFUG income generation from forest products have been steadily increasing over the years. This has
been the result of a devolution of power of forest resource management to local forest users. Chapagain
(2009) claim that 46% of “poor” community forest users have crossed the relative poverty line, largely
due to engagement in CFUG livelihoods improvement related activities and capacity building events.
Likewise, 35% of “very poor” households have moved to the poor category.
In eastern Nepal, CFUGs have invested US$327,000 over ten years in formal school education,
informal literacy programs for women and the poor, and scholarships for poor students. Some CFUGs
have contributed to construction and maintenance of roads, schools, irrigation canals, and health posts,
etc. Furthermore, community forests have had supportive influences on agriculture production, income
and employment generation, biodiversity conservation, democratic governance, social unity, and
literacy in society.
Through the CIA consultations with the members of Federation of Community Forest Users Nepal
(FECOFUN), Sankhuwasabha, 50% of the income from community forests in the district is invested in
income generating activities, education, and capacity building. Communities collect firewood and
house-building materials from the community forests. Forest resource collection complements
agriculture activities for farmers, as they collect fodder for livestock, and tree wastage to make compost
manure to cultivate crops. Traditional healers also depend on non-timber forest products (NTFPs) from
the community forests. Generally, vulnerable and disadvantaged groups are highly dependent on the
community forests for collection of food and herbs for medicinal purposes and for sale. Concerns were
raised during the downstream CIA consultations regarding the impacts of hydropower projects and road
developments on community forests. For instance, the Arun-3 HEP has impacted on community forests
by causing landslides and the expansion of Koshi highway is also negatively impacting on community
forests.
Value of Ecosystem Services from Forests
Pant et al. (2012) estimated the monetary value of the goods and services provided by the forest
ecosystems of three districts of eastern Nepal. The total economic value includes select provisioning,
regulating and supporting services as shown in Table 7.7. Based on the study, the total economic value
of the forest-based ecosystem services in the districts is NPR 8,905 million per year, which is equivalent
to approximately NPR 30,000 per ha per year (Table 7.8).
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UAHEP CUMULATIVE IMPACT ASSESSMENT BASELINE STATUS OF SELECTED VECS
Table 7.7: Ecosystem Services Valuation Methods Used
Source: Pant et al. 2012
Table 7.8: Total Value of Ecosystem Services from Forest Ecosystems
Source: Pant et al. 2012
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UAHEP CUMULATIVE IMPACT ASSESSMENT BASELINE STATUS OF SELECTED VECS
7.2 VEC: Makalu Barun National Park
The Makalu Barun National Park has been identified as a VEC due to its high biodiversity and
community value and potentially significant level of impacts from planned developments (including the
UAHEP and Num-Kimathanka Road). This section provides an overview of the historical and current
management approach, land cover, and baseline biodiversity and socio-economic setting.
7.2.1 Overview
The MBNP is an internationally recognized IUCN Management Category II protected area. MBNP was
established in 1992 as an eastern extension of the Sagarmatha National Park (under the National Parks
and Wildlife Conservation Act, 1973). It is one the world's few protected area with an elevation gain of
more than 8,000 m which encloses tropical forest as well as snow-capped peaks. The MBNP
encompasses a total area of 2,330 km2 (approximately 45% of the total Arun Basin) with 1,500 km2 of
the core area in Solukhumbu and Sankhuwasabha districts, with the surrounding Buffer Zone (as
declared in 1999) covering an area of 830 km2 to the south and southeast.
7.2.2 Management Approach
The MBNP is managed using a people-oriented approach, as per the Himalayan National Park
Regulation 2036 BS (1979 AD). According to this regulation, people living within the MBNP and its
Buffer Zone are entitled legal access to subsistence harvesting within those areas. However, it was
later realized that this arrangement was not sufficient to manage the biodiversity and ecological integrity
of the MBNP Core Area and Buffer Zone (Chapagain 2009). As a result, the National Park Management
Plan was designed in 1990 to recognize the legitimacy of traditional economic and subsistence activities
such as gathering medical herbs and economically useful plants such as Daphne malingo (bamboo).
The plan also emphasized the importance of “bottom-up” decision-making structure that incorporates
local knowledge. The Management Plan stipulates special use areas, such as Strict Nature Reserves
to protect places of exceptional ecological significance, and Special Sites and Trails designated to
accommodate tourism or traditional cultural activities (Carpenter and Zomer 1996).
7.2.3 Land Use and Land Cover
According to Kari et al. (2018), in 2002, 45% of the area was covered with rock, ice and snow, whereas
forest together with shrubland and grassland occupied almost half of the MBNP Core Area. More than
half of the Buffer Zone was covered with forest (58%), 16% by agricultural land, 20% by scrubland and
grassland altogether, and only 6% by rock, ice, and snow.
The LULC analysis conducted by ERM show that in 2018, 57% of the Core Area was covered with rock,
ice and snow, and the rest of the area comprised mainly forest (42%). For the Buffer Zone, the land use
pattern comprised 80% forest coverage, 10% agricultural land, 3.5% grassland, and the rest was made
up of rock and snow coverage. The significant increase in forest area could be a result of the park
management approach discussed in Section 7.2.2 and Section 7.2.6.
The traditional and subsistence use of forest resources is allowed in Buffer Zone areas of the MBNP,
such as cattle grazing, collecting fuelwood, timber and non-timber forest products, with the permission
of the chief conservation officer of MBNP.
Massive quantities of water are stored in snow and glacier ice in the upper elevations of the MBNP,
which are released continuously, forming seven major river tributaries. These tributaries which pour
southward into Arun and Dudh Koshi rivers. Solukhumbu and Sankhuwasabha districts comprise about
580 glacial lakes, of which 121 of these glacial lakes lie inside the MBNP. Groups of alpine, sub-alpine
lakes exist in the upper elevations of the MBNP; these high altitude wetlands include Bahula Pokhari,
Yekle Pokhari, Tin Pokhari, Jhale Pokhari, Panch Pokhar (bigger), Dudh Pokhari, Tama Pokhari, Panch
Pokhari (smaller), Thulo Pokhari and Sano Pokhari (Karki 2002).
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7.2.4 Socio-economic
The MBNP Buffer Zone covers an area with a total population of 34,467 individuals. People within the
Buffer Zone are mainly from Rai communities (64%) followed by Bhote (18%), Sherpa (8%), and
Tamang, Gurung, Newar, Chhetri, Brahmin and other castes (10%).
Most of the households are subsistence farmers engaged in agriculture and livestock herding.
Rotational slash and burn farming and animal husbandry are the main economic activities of the local
communities. Local households also depend upon the diverse national resources from the Buffer Zone.
The MBNP is an attractive tourism destination for trekking and mountaineering due to its landscape,
lakes, richness of flora and fauna and Mount Makalu, Buruntse, and Sherpin Col. However, there has
been limited tourism due to its difficult terrain and limited accessibility. A total of 1,000–1,500 tourists
visit the MBNP and its Buffer Zone annually (Sherpa 2002), and a total income of USD 43,000 (NPR
4.3 million) was generated for the park during 2016/17, which is considerably lower than other popular
areas like Chitwan National Park, which had a total earnings of USD 2.01 million (NPR 201 billion)
during the same period (DNPWC 2017).
7.2.5 Biodiversity
The MBNP protects a broad range of Eastern Himalayan forest types, ranging from near-tropical
dipterocarp monsoon forest (400 m) to subalpine conifer stands (4,000 m). Forests span over five
bioclimatic zones (tropical, subtropical, lower and upper temperate, and subalpine), but ecotones are
poorly defined. Below 2,000 m forests are strongly affected by subsistence agriculture, although some
ecologically significant stands remain at those elevations. Above 2,000 m, a cool, humid climate
suppresses agricultural activity and forests are usually extensive (Carpenter and Zomer 1996).
Table 7.9 shows the number of species types recorded in the Makalu-Barun National Park (Karki et al.
2018), which are further detailed below.
Table 7.9: Number of Species Types Recorded in the MBNP
Mammals Reptiles Amphibians Birds Fish Butterfly Endemic Plants
Plants
86 43 13 421 78 315 7 3,073
Source: Buffer Zone Management Plan, MBNP (2005)
Flora and Fauna
More than 3,000 species of flowering plants are found in the MBNP, among which 56 species are rare
and endangered. Almost two hundred (199) species of flowering plants have been recorded from the
park (TMI and IUCN 1995). Seven (7) species of endemic flowering plants have been recorded in the
MBNP, which includes Desideria nepalensis, Pedicularis pseudoregeliana, Carex himalaica, Kobresia
gandakiensis, Kobresia, fissiglumis, Ranunculus himalaicus, and Ranunculus makaulensis.
Panchaunle (Dactylorhiza hatagirea) and kutki (Neopicrorhiza scrophulariiflolia) are plant species
protected by the Government of Nepal that are also found in the MBNP. Similarly, over 86 species of
mammals, including the threatened snow leopard (Pantherauncia), musk deer (Muschus chrysogaster),
red panda (Ailurus fulgens), clouded leopard (Neofelis nebulosa), spotted linsang (Prionodon
pardicolor) and Assamese monkey (Macaca assamensis), are found in this park.
Birds
A total of 421 bird species have been recorded within the park and its Buffer Zone. The park is especially
important for the globally threatened wood snipe, and the near threated satyr tragopan and yellow-
rumped honeyguide, which are resident and likely breed in the park region. The MBNP is also of
importance to seven (7) restricted-range species from the Central and Eastern Himalayas EBAs that
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are likely resident in the area, namely: the yellow-vented warbler, broad-billed warbler, Nepal wren
babbler, rufous-throated wren babbler, spiny babbler, hoary-throated barwing, and white-naped yuhina
(TMI and IUCN 1995). In addition, the spiny babbler (Turdoides nipalensis) (Nepal’s endemic bird
species), and the green cochoa (Cochoa viridis) (classified as extinct in Nepal), were sighted in the
MBNP in 1990 (Bhuju 2007).
For this reason, the MBNP is identified as an Important Bird and Biodiversity Area (IBA), according to
several criteria: A1 (globally threatened species), A2 (restricted range), and A3 (biome-restricted
species) (BirdLife International 2020). As the MBNP triggers IBA criterion A2 (restricted range species),
it has been classified as an Endemic Bird Area. EBAs are regions that represent natural areas of bird
endemism where the distribution of two or more restricted-range bird species overlap, where restricted-
range refers to a breeding range of no more than 50,000 km 2 (BirdLife International 2018). Details of
the bird species that meet IBA criterion A2 found in the CIA study area are presented in Table 7.10.
Table 7.10: Bird Species that Meet IBA Criterion A2 Found in the CIA Study
Area
Common Name Scientific Name IUCN Red List Category
Spiny babbler Turdoides nipalensis LC
Hoary-throated barwing Sibia nipalensis LC
Rufous-throated wren-babbler Spelaeornis caudatus NT
Yellow-vented warbler Phylloscopus cantator LC
Broad-billed warbler Tickellia hodgsoni LC
Nepal wren babbler Pnoepyga immaculata LC
White-naped yuhina Yuhina bakeri LC
Notes: LC = Least concern; NT = Near Threatened
Source: Birdlife International 2020
The EBAs overlapping the Arun Basin are provided in Figure 7.4 with a description of each EBA and
the A2 trigger species are provided in Table 7.11.
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Table 7.11: EBAs Overlapping the Arun Basin
Endemic Location Diversity
Bird Area
Eastern This EBA follows the Himalayan As they lie further to the south, the mountains of this region have
Himalayas range east from the Arun-Kosi a distinctly different climate (and, hence, vegetation) from the
valley of eastern Nepal, through rest of the Himalayas: they experience warmer mean
Bhutan, north-east India (Sikkim, temperatures and fewer days with frost, and generally have a
northern West Bengal and much higher rainfall. Two evergreen forest types appear to be
Arunachal Pradesh), south-east particularly important breeding habitats for the EBA's restricted-
Tibet Autonomous Region and range birds, both of which reach their western limit in eastern
north-east Myanmar to south-west Nepal: subtropical wet hill forest is found at altitudes between
China (north-west Yunnan approximately 1,000 and 2,000 m, and wet temperate forest at
province). altitudes of about 1,800-3,000 m.
This part of the Himalayas is particularly rich in restricted-range
birds, and the genus Sphenocichla is endemic to the EBA.
Central This EBA extends through the Two of the three restricted-range birds, Pnoepyga immaculata
Himalayas Himalayas from the extreme east of and Sibia nipalensis, breed in Himalayan moist temperate forest
Nepal to the extreme west, and between about 1,800 and 3,300 m, and Turdoides nipalensis
possibly into adjacent regions of occupies dense scrub and secondary growth at slightly lower
India. altitudes. The newly described P. immaculata is apparently an
altitudinal migrant, as it has been recorded in the lowlands of
southern Nepal outside the breeding season; it has only been
recorded in Nepal so far, but may prove to be present elsewhere
in the Himalayas
Source: BirdLife International 2019
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Figure 7.4: EBAs Overlapping the Arun Basin and MBNP
Source: ERM 2020
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Threatened Species and Critical Habitat
Threatened Species
The Integrated Biodiversity Assessment Tool (IBAT) was used to determine the potential critical habitat
species (Critically Endangered/Endangered) within the study area. For the IBAT search, a 50 km radius
from the UAHEP project location was used, which included the Makalu-Barun National Park, the Tamor
Valley and Watershed, and the Kanchenjunga Conservation Area.
Threatened species that have been identified within the study area – according to the IBAT results,
IUCN Red List of Threatened Species, and the National Red List for Nepal – are listed in Table 7.12.
The Red List provides the conservation status of these listed species as being Critically Endangered
(CR), Endangered (EN) and Vulnerable (VU). CR, EN and VU species are considered to be at a
heightened risk of extinction and are awarded an elevated level of consideration under IFC PS6.
Species identified as endemic, restricted range, migratory and/or congregatory according to the relevant
IUCN species profiles are also listed in order to assess against the thresholds for critical habitat criterion
2 (endemic and/or restricted-range species) and/or criterion 3 (migratory and/or congregatory species).
Where species have not yet been evaluated by IUCN, the protection status has been considered.
Critical Habitat
As detailed in the UAHEP ESIA (Section 6.2 Terrestrial and Aquatic Biodiversity), the terrestrial areas
of the MBNP qualify as critical habitat (CH), as they are likely to maintain populations of six CH-
qualifying terrestrial species (Himalayan red panda, black musk deer, Chinese pangolin, clouded
leopard, spotted linsang, and Himalayan black bear). A section of the Arun River is located within the
MBNP Buffer Zone area, which could contain potentially suitable habitat for the golden mahseer.
However, the targeted electrofishing surveys did not indicate the presence of golden mahseer in the
UAHEP project area. The Arun River in the project area is not considered critical habitat. However, the
terrestrial areas of the MBNP are considered critical habitat and must achieve net gain of these
biodiversity values. Additonal study on the critical habitat assesemnt has been carried out to confirm
that Himalayan red panda, clouded leopard, spotted linsang, and Himalayan black bear qualified as
critical habitat species; and mitigation plans have been developed and budgeted. This net gain has
been demonstrated in the ESIA and in the report by Red Panda Network Nepal (2023) Critical Habitat
Assessment of the Upper Arun Hydro-electric Project and its Biodiversity Management Plan (BMP).
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Table 7.12: Terrestrial Species of Conservation Significance
S/N Class Scientific Name Common Name Migratory Endemic/ IUCN Listing National Red CITES2
Restricted List for Nepal1
Range
1. Birds Aythya baeri Baer's pochard Yes No CR CR -
2. Birds Emberiza aureola Yellow-breasted Yes No CR CR -
bunting
3. Birds Gyps bengalensis White-rumped vulture No No CR CR II
4. Birds Gyps tenuirostris Slender-billed vulture No No CR CR II
5. Birds Sarcogyps calvus Red-headed vulture No No CR EN II
6. Mammals Manis pentadactyla Chinese pangolin No No CR EN I
7. Birds Aquila nipalensis Steppe eagle Yes No EN VU II
8. Birds Falco cherrug Saker falcon Yes No EN EN II
9. Birds Haliaeetus Pallas's fish-eagle Yes No EN CR II
leucoryphus
10. Birds Leptoptilos dubius Greater adjutant Yes No EN CR -
11. Birds Neophron Egyptian vulture Yes No EN VU II
percnopterus
12. Birds Sterna acuticauda Black-bellied tern No No EN CR -
13. Fish Tor putitora Golden mahseer No No EN - -
14. Mammals Ailurus fulgens Red panda No No EN EN I
15. Mammals Cuon alpinus Dhole No No EN EN II
16. Mammals Caprolagus hispidus Hispid hare No No EN EN I
17. Mammals Elephas maximus Asian elephant No No EN EN I
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S/N Class Scientific Name Common Name Migratory Endemic/ IUCN Listing National Red CITES2
Restricted List for Nepal1
Range
18. Mammals Moschus Alpine musk deer No No EN EN I/II/NC
chrysogaster
19. Mammals Moschus fuscus Black musk deer No No EN DD I/II
20. Mammals Moschus Himalayan musk deer No No EN DD I
leucogaster
21. Birds Antigone Sarus crane Yes No VU VU II
22. Birds Aquila heliacal Eastern imperial eagle Yes No VU CR I
23. Birds Aquila rapax Tawny eagle No No VU - II
24. Birds Aythya farina Common pochard Yes No VU NT -
25. Birds Gallinago Wood snipe Yes No VU VU -
nemoricola
26. Birds Grus nigricollis Black-necked crane Yes No VU DD I
27. Birds Leptoptilos Lesser adjutant Yes No VU VU -
javanicus
28. Birds Mulleripicus Great slaty No No VU EN -
pulverulentus woodpecker
29. Birds Ploceus Finn's weaver No No VU CR -
megarhynchus
30. Birds Prinia cinereocapilla Grey-crowned prinia No No VU CR -
31. Birds Saxicola insignis White-throated Yes No VU EN -
bushchat
32. Mammals Aonyx cinereus Asian small-clawed No No VU - II
otter
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S/N Class Scientific Name Common Name Migratory Endemic/ IUCN Listing National Red CITES2
Restricted List for Nepal1
Range
33. Mammals Arctictis binturong Binturong No No VU - III
34. Mammals Bos gaurus Guar No No VU VU I
35. Mammals Lutrogale Smooth-coated otter No No VU EN I
perspicillata
36. Mammals Myotis sicarius Mandelli's mouse- No No VU VU -
eared myotis
37. Mammals Neofelis nebulosa Clouded leopard No No VU EN I
38. Mammals Panthera pardus Leopard No No VU VU I
39. Mammals Panthera uncia Snow leopard Yes No VU EN -
40. Mammals Rhinoceros Greater one-horned No No VU P I
unicornis rhino
41. Mammals Rusa unicolor Sambar No No VU VU -
42. Mammals Ursus thibetanus Asiatic black bear No No VU EN I
43. Mollusc Tricula - No No VU - -
mahadevensis
44. Reptiles Crocodylus palustris Mugger No No VU - I
45. Reptiles Python bivittatus Burmese python No No VU - II
46. Flowering Anacyclus Atlas daisy No No VU - -
plants pyrethrum
47. Birds Falco severus Oriental hobby Yes No LC CR II
48. Birds Halcyon coromanda Ruddy kingfisher Yes No LC CR -
49. Birds Haliaeetus albicilla White-tailed sea-eagle Yes No LC CR I
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S/N Class Scientific Name Common Name Migratory Endemic/ IUCN Listing National Red CITES2
Restricted List for Nepal1
Range
50. Birds Loriculus vernalis Vernal hanging-parrot Yes No LC CR II
51. Birds Numenius arquata Eurasian curlew Yes No NT CR -
52. Birds Pelecanus Spot-billed pelican Yes No NT CR -
philippensis
53. Birds Aegypius monachus Cinereous vulture Yes No NT EN II
54. Birds Botaurus stellaris Eurasian bittern Yes No LC EN -
55. Birds Rallina eurizonoides Slaty-legged crake Yes No LC EN -
56. Birds Asio flammeus Short-eared owl Yes No LC VU II
57. Birds Aythya nyroca Ferruginous duck Yes No NT VU -
58. Birds Ciconia nigra Black stork Yes No LC VU II
59. Birds Circus aeruginosus Western marsh-harrier Yes No LC VU II
60. Birds Circus cyaneus Hen harrier Yes No LC VU II
61. Birds Clamator Chestnut-winged Yes No LC VU -
coromandus cuckoo
62. Birds Falco naumanni Lesser kestrel Yes No LC VU II
63. Birds Ficedula hodgsoni Pygmy blue-flycatcher Yes No LC VU -
64. Birds Ficedula sapphira Sapphire flycatcher Yes No LC VU -
65. Birds Galerida cristata Crested lark Yes No LC VU -
66. Birds Gallicrex cinerea Watercock Yes No LC VU -
67. Birds Gyps himalayensis Himalayan griffon Yes No NT VU II
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S/N Class Scientific Name Common Name Migratory Endemic/ IUCN Listing National Red CITES2
Restricted List for Nepal1
Range
68. Birds Hydrophasianus Pheasant-tailed jacana Yes No LC VU -
chirurgus
69. Birds Limosa Black-tailed godwit Yes No NT VU -
70. Birds Macropygia unchall Barred cuckoo-dove Yes No LC VU -
71. Birds Nettapus Cotton pygmy-goose Yes No LC VU -
coromandelianus
72. Birds Pitta sordida Western hooded pitta Yes No LC VU -
1
Nepal Red List of Birds and Mammals, 2011
2
Convention on International Trade in Endangered Species of Wild Fauna and Flora:
- Annex I includes species threatened with extinction. Trade in specimens of these species is permitted only in exceptional circumstances.
- Annex II includes species not necessarily threatened with extinction, but in which trade must be controlled in order to avoid utilization incompatible with their survival.
- Annex III contains species that are protected in at least one country, which has asked other CITES Parties for assistance in controlling the trade.
Notes: LC = Least Concern; VU = Vulnerable; EN = Endangered; NT = Near Threatened; CR = Critically Endangered; DD = Data Deficient; NT = Not Listed; P = Protected – = No; X = Yes
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7.2.6 MBNP Conservation Projects
The Makalu-Barun Conservation Area Project was initiated in 1988 as a joint endeavor of the
Department of National Parks and Wildlife Conservation (DNPWC), an INGO called The Mountain
Institute (TMI), and local organizations and committees, with the aim of promoting a participatory
approach towards sustaining biodiversity conversation and management for long-term benefits. The
activities initiated since 1992 include:
◼ Community development: eco-tourism development and income-generation programs (off-farm
activities and market development for local products)
◼ Local culture conservation
◼ Natural resource management:
- Community forestry programs
- Grazing area management: prepared grazing area management plan and its operation
The outcomes of the Partnership Project12 for improving local livelihoods and biodiversity conservation
include:
◼ Over 97 CFUGs have been formed, which are managing over 11,500 ha of natural forests, covering
over 90% of households in the MBNP area.
◼ Six Grazing Area Management User Groups were formed and four Operational Plans for grazing
areas were realized.
◼ Eight forest nurseries have been established and are owned and operated by local farmers in the
MBNP area, covering 37 ha of degraded community and private land.
◼ There has been significant forest recovery and improved forest conditions in the MBNP Buffer Zone
areas through voluntary conservation by local communities.
◼ Wildlife poaching and hunting are under control; the local communities help arrest hunters and
poachers.
◼ The Project has supported over 250 small-scale infrastructure development projects, such as
providing a drinking water supply system and improving trails and school facilities.
◼ An agreement was made for managing natural resources and eco-tourism across the Himalayan
boundary between Nepal and Tibet Autonomous Region of China (Jha 2003).
◼ The Project has improved the livelihoods of over 3,000 people through the provision of livelihood
improvement training programs such as weaving and knitting, trekking, cooking and managing
lodges, carpentry, and bamboo craft, among other things. Furthermore, the Project has also
supported the conservation of local culture by constructing and maintaining temples, gompas, and
sacred places, etc.
7.3 VEC: Water Resources
7.3.1 Arun River Basin
The Arun River is a tributary of the Sapta Koshi River, which in turn is a tributary of the Ganges River
in India, which ultimately discharges into the Indian Ocean in the Bay of Bengal (see Figure 7.5). The
river originates from a glacier on the north slope of Mount Xixabangma (elevation 8,012 m) and the
southern part of the Tibetan highlands in the Tibet Autonomous Region of China.
12
The Partnership Project is the collaborative efforts of the Government of Nepal, The Mountain Institute, and local
communities in promoting participatory approaches towards sustaining the conservation of the MBNP and its Buffer Zone, as
well as improving the livelihoods of local people (Jha 2003).
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Figure 7.5: Arun River Drainage
Source: Reynolds 2020
The Arun River has a total drainage area of approximately 30,400 km2, with approximately 83% of that
draining from China (Figure 7.6). The Arun River drainage areas at key locations are listed below:
◼ Drainage area at China border – 25,307 km2
◼ Drainage area at UAHEP dam – 25,700 km2
◼ Drainage area at UAHEP powerhouse – 26,300 km2
◼ Drainage area near Tumlingtar – 28,150 km2
◼ Drainage area at confluence with Sapta Koshi River – 30,400 km2
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Figure 7.6: Arun River Basin
The Arun River is the largest trans-Himalayan river passing through Nepal and has the greatest snow
and ice covered area of any Nepali river basin (Kattelmann 1990). The Arun River drains more than
half of the Sapta Koshi River Basin, but provides only about a quarter of the total flow, which is
attributable to the fact that more than 80% of the Arun’s drainage area is within the Himalaya rain
shadow in Tibet Autonomous Region, where average annual precipitation is less than about 300 mm,
as compared to about 2,400 mm in the Nepal portion ( Figure 7.7).
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Figure 7.7: Average Annual Rainfall in the Koshi Basin
Source: Neupane et al. 2014
7.3.2 Arun River Flow Characteristics
The Arun River is a relatively high volume, high gradient/high velocity, glacier-fed (i.e., cold with high
sediment load) river. In terms of flow, there are five Nepal Department of Hydrology and Meteorology
(DHM) gauging stations along the Arun River, as summarized in Table 7.13. The Uwa Gaon gauging
station, which is located just downstream from the UAHEP powerhouse, is the closest gauge to the
Project Area and provides about 25 years of consecutive flow data. Three staff gauges were installed
in April 2018 at the confluence of the Arun River with Chepuwa Khola, the powerhouse site, and
Leksuwa Khola; and an automatic gauging station was installed at the dam site in June 2018.
Table 7.13: Nepal DHM Flow Gauging Stations along the Arun River
Station Location Longitude Latitude Catchment Flow Series
No. Area (km2)
600.1 Uwa Gaon 27°35’21” 27°35’21” 26,620 1985–2010
604.5 Turkeghat 87°11’30” 87°11’30” 28,200 1975–2014
606 Simle 26°55’42” 26°55’42” 30,380 1986–2010, 2012–2016
602 Tumlingtar 87°12’45– 87°12’45” 409 1974–2016
602.5 Pipletar 87°17’45” 87°17’45” 148.5 1974–1976, 1976, 1984–2016
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The flow in the Arun River is subject to strong seasonal effect as evidenced in average monthly flows:
◼ December to February – The lowest flows occur during the winter when the little precipitation that
occurs is as snow.
◼ March to early June – Still the dry season, but flows slowly begin to increase as warming
temperatures slowly start to melt accumulated snow and ice.
◼ Mid-June to mid-September – The monsoon season has the highest flows, due to heavy rainfall
combined with snow and ice melt.
◼ Late September to November – Gradually decreasing flows, as the monsoons end and
temperatures begin to cool.
The Arun River is currently free flowing for its entire length with no existing hydropower, irrigation, or
other dams along its course. This will change in the near future, as Arun-3 HEP is already under
construction and several other main stem hydropower projects are proposed, including Kimathanka
Arun, Upper Arun, Arun-4, Arun-3, Lower Arun, and the Sapta Koshi High Dam, which, although
proposed to be located on the downstream Sapta Koshi River, will inundate the lower portion of the
Arun River.
The Arun River is used for multiple purposes along its length, including subsistence, recreational, and
commercial fishing; recreational boating; cultural practices (e.g., cremations); and irrigation (discussed
in more detail in Section 7.4 VEC: Fish and Aquatic Habitat and Section 7.5 VEC: River-based
Livelihoods).
7.4 VEC: Fish and Aquatic Habitat
7.4.1 Fish Diversity in the Arun River Basin
There is currently no available full fish data survey indicating species diversity and gradient along the
Arun River. As such, this section has been developed based on the following sources:
◼ Arun-3 HP EIA, (WAPCOS Limited 2015)
◼ FAO Technical Paper 431 (Petr et al. 2002)
◼ Species list prepared by K.J. Rajbanshi (Rajbanshi 2002)
◼ CIA of Tamor (ERM 2019), which is the neighboring river just east of Arun
◼ EIA of the Dudhkoshi Storage Hydropower Project (EIA of DKSHEP, 2020, ELC in prep), which is
located in an adjacent river to the west of Arun River
◼ ESIA of the Upper Arun Hydropower project (ERM, forthcoming)
According to FAO’s Technical Paper 431 (Petr et al. 2002), the part of the Koshi River system
downstream from Arun has 31 registered fish species, the neighboring Dudhkoshi River west of Arun
has 31 registered species in the lower part of the river, and the Middle Tamor east of Arun has 50
registered species. In 2002 Rajbanshi listed 31 species in the Arun River, and the EIA for the Arun-3
HEP (2015) lists 22 registered species. Sampling in the Upper Arun area collected 5 species, while
local people reported 21 species including the river section downstream from the Arun-3 HEP.
By compiling the available data from the aforementioned sources and qualifying the data against the
IUCN (www.iucnredlist.org) and Fishbase (http://www.fishbase.org) databases, the list of species that
are reasonably found in the Arun River Basin constitutes 44 species, as presented in Annex D.
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7.4.2 Target Fish Species
When selecting target species as a tool to understand the impacts and mitigating strategies, it is
important that the target species are also present in the CIA area, and that the species will potentially
be affected by the proposed Project. In addition, the species should meet the following criteria:
◼ Single species that cover the ecological needs for a larger group of species (representatively)
◼ IUCN red listed species, and endemic species
◼ Long and medium range migratory species
◼ Locally valuable species
Guided by the aforementioned criteria, the fish species shown in Table 7.14 have been selected based
on expert opinions, field surveys, and consultations with local people. Table 7.15 shows the migration
and spawning seasons for selected key fish species
Table 7.14: Target Fish Species
Species English name Local name Comments
Anguilla bengalensis (bam) Eel Raj bam Long migrant
Tor putitora (mahseer) Golden mahseer Sahar Long migrant
Schizothorax richardsonii Common snow Butche asala Mid migrant
trout
Neolissocheilus hexagonolepis Copper mahseer Katle Mid migrant
Labeo dero River rohu Gardi Mid migrant
Glyptosternum blythi Dwarf catfish Tilkabre Strong climber, up to 3,000 masl
Psilorhynchoides Stone carp Titae Endemic, strong climber
pseudecheneis (titae)
Box 7.1: Description of Target Species
Freshwater Eel (Anguilla bengalensis)
Nepali name: Rajabam or bam
Physical features:
The body of this freshwater eel appears
naked, but small cycloid scales are
embedded in the skin. The body is
covered by mucus, which makes it
slippery, giving rise to the expression
“slippery as eel”. It is an excellent game
fish.
Fresh water eel (rajabam)
Feeding: It lives in deep stone crevices feeding actively on young fish and molluscs.
Spawning and migration: It lives in freshwater, but also occurs in estuaries and in the sea during early life and
near maturity in the bay of Bengal (www.fishbase.org). It is believed to begin life in the ocean and then migrate
to freshwater as an immature eel; they spent most of their life in freshwater and return to the ocean to spawn
and die. They are a long migrant species and are known to migrate upstream during the monsoon floods from
May to August.
Economic importance: Highly valued for food. Highest price range.
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Distribution: Asia: Pakistan, India, Sri Lanka, Burma, and the East Indies, N epal and Bangladesh
(www.fishbase.org). Endangered status in India (Arunachalam and Sankaranarayanan 2000).
Conservation status: IUCN: Vulnerable
Golden mahseer (Tor pitutora)
Nepali name: Sahar
Physical features:
The golden mahseer is a beautiful
freshwater game fish. The snout of this
fish is long and pointed. It is noted for its
large 9 predorsal scales, which is not
possessed by any other fishes inhabiting
the mountain streams. General body Golden mahseer (sahar)
colour is silvery green to olive green
above, belly silvery white pinkish on
sides, and fins are yellowish.
Feeding: It mainly feeds on macroinvertebtares and fish.
Spawning and migration: The golden mahseer is a long range migrant fish, which migrates upstream for
spawning. The ideal time for the spawning is from July to September, when the river has a high water level. A
mature golden mahseer of 45 cm yields 6,300 to 28,000 eggs.
Generally, spawning of the golden mahseer starts at the confluence of warm tributaries or in the lower parts of
these tributaries, where water is highly oxygenated and has moderate velocity. The suitable water depth for
spawning is 2 to 5 m.
Economic importance: Highly valued for food. Highest price range.
Distribution: It occurs in high mountain streams, up to 1,200 masl, although this varies depending on water
temperatures and other factors. It is found in the Koshi river sytem and in several of the large tributaries of
Tamor, Arun and Dudhkoshi, as well as in the Trishuli, Gandaki, Karnali, and Mahakali river systems, and feeder
streams. This fish is also found in India, Pakistan, Myanmar, Sri Lanka and Bangladesh.
Conservation status IUCN: Endangerd
Common snow trout (Schizothorax
richardsonii)
Nepali name: Buche asala or asala
Physical feature:
The snout of the common snow trout is
rather blunt and its body is trout like, but
more cylindrical. The mouth is inferior. Its
general body colour is silvery with golden
yellow spangles on the sides. The paired
Common snow trout (buche asala)
fin is often tinged with red.
Feeding: The snow trout feeds on almost any aquatic algae and organic matter, mainly in the early morning and
evening.
Spawning and migration: This is a midrange migrant fish. It generally becomes sexually mature after 2 years
and female produces about 33,000 to 55,000 eggs. The species has two breeding seasons; September/October
and Spring March/April.
Economic importance: Highly valued for food. Highest price range.
Distribution: It occurs in high mountain streams and in most of the river systems in Nepal.
Conservation staus: IUCN: Vulnerable. See Annex E for an esimated distribution of this species in the Arun
Basin.
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Copper mahseer (Neolissochilus
hexagonolepis)
Nepali name: Katle
Physical features:
The lower lip is separated from the jaw
with a horny covering. Further, it has a
osseous dorsal spine, two pairs of
barbells, large scales, a olive-green
colour on the dorsal side, and a silvery
white colour below.
Copper mahseer (katle)
Feeding: Copper mahseer is an omnivorous fish.
Spawning and migration: The spawning behaviour is similar to the golden mahseen and it spawns in June-
September when the river has high water levels. The copper mahseer is a mid range migratory fish. Their
migration is limited to 5–10 km.
Economic importance: Highly valued for food. Highest price range.
Distribution: Mountain rivers up to more than 1,000 masl.
Conservation status: IUCN: Vulnerable. See Annex E for an esimated distribution of this species in the Arun
Basin.
River rohu (Labeo dero)
Nepali name: Gardi
Physical features:
The river rohu has a medium-sized, snout
with many horny tubercles. It is bluish black
above, with silver sides and yellowish
ventral fins. The whole body of the fish is
covered by large scales. River rohu (gardi)
Feeding: Its main food is algae, fish, crustaceans and frogs.
Spawning and migration: This fish is a resident or a short range migrant species. It ascends hill-streams for
spawning during May-June in shallow water over plants and gravel.
Economic importance: Highly valued for food. Highest price range.
Distribution: Mountian rivers up to more tha 1,000 masl.
Conservation status: IUCN: Not Threatened
Dwarf catfish (Glyptosternum blythi)
Nepali name: Tilkabre and telkabre
Physical features: The dwarf catfish’s head
is depressed with a broad snout. Its lips are
broad and continuous and its mouth is
round with papillation, which helps the fish
adhere to rocks. Its body colour is yellowish
Dwarf catfish (tilkabe or telkabre)
brown and its dorsal and caudal fins are
tinged with black.
Feeding: The dwarf catfish is omnivorous, feeding on aquatic insects, tadpoles, and earthworms.
Spawning and migration: A resident fish that breed in May and June.
Economic importance: None. Not used as food.
Distribution: Asia, endemic to Nepal (www.fishbase.org).
Conservation status: Not evaluated by IUCN
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Stone carp (Psilorhynchus
pseudecheneis)
Nepali name: Titae
Physical features: Its body is elongated,
depressed and flattened with 3 to 5 distinct
transverse folds on the ventral side.
Generally, its body colour is dark with
greenish spangles on the dorsal sides. A
few dark blotches and bands are present in
front of the dorsal fin as well as behind. Its
scales are pigmented with black. The Stone carp (titae)
length of a full mature fish is around 18 cm.
Feeding: Its food consist of algae, small aquatic insects, tiny molluscs, and crustaceans.
Spawning and migration: The stone carp is a resident and a short range migrant fish. Its main spawning period
is August. It enters to small tributaries for spawning. Spawning takes place in shallow riffles of streams.
Economic importance: This fish has a bitter taste and has medicinal value for abdominal diseases.
Distribution: Endemic to eastern Nepal (www.fishbase.org).
Conservation tatus: Endemic and IUCN: Least Concern
Table 7.15: Migration and Spawning Patterns for some Selected Species
Species Migratory Pattern by Month Spawning
Long-distance migratory fish J F M A M J J A S O N D
Anguilla bengalensis (bam) ↑ ↑ ↑ ↑ ↓ ↓ ↓ Jun–Jul
Tor putitora (sahar or golden mahseer) ↑ ↑ ↑ ↑ ↑ ↓ ↓ ↓ July, Oct
↓
Tor tor (putitor mahseer) ↑ ↑ ↑ ↑ ↓ ↓ ↓ Aug–Oct
↓
Short/medium-distance migratory fish J F M A M J J A S O N D
Neolissochelius hexagonolrpis (katle) ↑ ↑ ↑ ↑ ↑ ↓ ↓
↓
Labeo dero (gardi) ↑ ↑ ↑ ↑ ↑ ↓ ↓ Varies*
Schizothorax richardsonii (butche asala) ↑ ↑ ↑ ↑ ↓ ↓ ↓ Varies*
Schizothorax progastus (chuche asala) ↑ ↑ ↑ ↑ ↓ ↓ ↓ Varies*
Resident fish
Psilorhynchoides pseudecheneis (titae) ↑ ↑ ↓ ↓ August
Glyptosternum blythi (tilkabre) ↑ ↑ ↓ ↓ May–Jun**
Notes: * Varies with the local thermal regime and flooding conditions. ** Low level knowledge about the species ecology.
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7.4.3 Aquatic Habitats
Assessing the basin for fish diversity will require an understanding of temperature variations, and
species composition and distribution; therefore, ERM has used existing EIAs of projects in the basin
and other studies carried out by ERM to create a digital elevation model (DEM) of the basin that
specifies the elevation across the basin. Temperatures of river reaches at varying elevations, obtained
from other basins, were used to delineate three zones in the basin (Figure 7.8):
◼ Cold – upstream of ~800 masl, this is specific for the glacier fed Arun River
◼ Cold-cool (~800 to ~400 masl)
◼ Cool (downstream of ~400 masl)
Table 7.16 lists the physical characteristics of key Arun River tributaries.
Table 7.16: Physical Characteristics of Tributaries along the Arun River
Tributary Physical Characteristics Zone
Chujung Khola – Snow and glacier fed, high sediment load Cold at confluence
Left bank (upstream from UAHEP)
Barun river – Right Steep gradient, high sediment load, glacier fed Cold at confluence
bank
Lexuwa Khola – Clear water river during winter and spring, not snow fed, Cold-cool at confluence
Left bank dominated by boulders
Ikhuwa Khola – Clear water during winter and spring, steep gradient, Cold-cool at confluence
Left bank dominated by boulders and stones
Induwa Khola – Clear, steep gradient Cold-cool at confluence
Left bank
Hingsa Khola – Clear river, steep gradient Cold-cool at confluence
Right bank
Isuwa Khola – Glacier and snow fed, turbid/clear, steep gradient, no Cold at confluence
Right bank temperture
Apsuwa Khola – Snow and glasier fed, turbid/clear, steep gradient, no Cold at confluence
Right bank temperature
Sangkhuwa Khola Clear, low level snow fed Cool at confluence
– Right bank
All tributaries Clear during winter and spring, ecological value depend on Cool at confluence
further the year cycle flow conditions, but usually good habitats
downstream
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Figure 7.8: Three River Temperature Zones in the Arun Basin
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7.5 VEC: River-based Livelihoods
For this CIA, livelihoods encompass income and activities required to secure the necessities of life for
people in the Arun River Basin. Emphasis is placed on river-based livelihoods, as they would be most
impacted by planned hydropower projects in the basin.
7.5.1 River-based Sources of Income
Fishing
There is a lack of temporally and spatially comparable data on fishing within the Arun River Basin. The
following is general fishing livelihood information that has been obtained from available hydropower
project EIAs/IEEs and the CIA consultations in the Arun River Basin.
Fishing has long been a livelihood source in Nepal, given the importance of fish and other aquatic
products due to their nutritional, religious, and cultural value in Nepalese society (Gurung and Sah
2016). Fishing communities were consulted during the CIA downstream consultations in Khandbari
Urban Municipality and Shaba Pokhari Rural Municipality of Sankhuwasabha District (Figure 7.9). The
consulted communities included ethnic groups (Bhahmin/Chhetri, Newar, Dalits, janajatis) in Katle
Bhanjyang settlement; the Kumul and Majhi communities in Tumlingtar; and mixed ethnic groups in
Barhabishe Bazar; as well as local fish markets.
According to the consultations, fishing is not a sole source of income and is typically conducted only six
months of the year (from April to November). Local residents rely on other economic activities for
income, including agriculture (growing crops, vegetables, maize, lentils, cash crops, etc.), running
hotels, tea stalls, teaching, and office work; some have migrated for foreign employment or are self-
employed (driving vehicles and tractor). For these communities, fishing is generally for household
consumption, and their surplus catch may be sold at local fish markets (e.g., Tumlingtar market and Hat
Bazar in Khandbari) to supplement their income. Fish is valued as special food for family consumption
as it is considered nutritious; dried fish is also valued as a gift to relatives and friends. Moreover, fish is
essential for various spiritual practices, for example, fish are used to perform death rituals of the Majhi
and the Limbu, and fish is used during Kul Puja (an annual ritual to worship God specific to their
community) by the Rai, Kumal, and Majhi.
The fishermen consulted typically engage in fishing activities twice a week, depending on fish availability
in the river. Fishing activities usually take place all year round, although are more common before the
monsoon (February/March/April) and after the monsoon season (late September, October/November).
Communities typically use traditional fishing gear, such as cast nets, gill nets, lift nets and various other
nets with indigenous names; different types of traps and baskets; as well as rods and lines for
subsistence fishing. Some community members of the Kumal community in Tumlingtar also make
fishing gear and bamboo fish storage containers for sale. However, destructive fishing approaches,
such as the use of explosive materials and electric fishing, were reported in the basin. During the
consultations, various communities expressed concern that these approaches are negatively impacting
fish habitats and spawning grounds.
On average, fishermen catch 1–3 kg of fish per day; the volume can be higher depending on river
conditions. The use of explosives and electric fishing can sometimes result in 8 –10 kg of fish being
caught per day. According to consultations with communities in Boharatar, Barhabishe Bazar,
Tumlingtar, and the DCC Officer, popular sites for fishing in the area include Arun River, Shabha River,
Hewa River, Sankhuwa River, Sisuwa River, Khangluwa, Newa River, Pilwa Khola, and Sankhuwa
Khola. Common fish species caught in the Arun River Basin are asala, buduna, singe, gunj, katle, sahar,
thed, bam tikhe, and titae (Figure 7.10).
Men and young boys generally undertake fishing activities. Women, however, are responsible for drying
fish and selling them in local markets. Dried fish is commonly sold in more volume than fresh fish,
because fish is easily perishable, therefore, it is preserved for long time marketing. The fishermen
generally earn an average of NPR 1,200 per day, according to a key informant interview from the Majhi
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community. Market prices for fish are dependent on fish species and size, with small fish selling for
NPR 600 per kg and large fish selling for NPR 1,000 per kg, while dried fish may sell for NPR 5,000 per
kg.
The consulted communities expressed concern that the local fish population has reduced significantly
over the past five to ten years. They further explained that frequent landslides/flood in the Shaba Khola
and Arun River, the use of electrofishing and explosives for fishing, the development of hydropower
projects, and mining gravel and sand from the river were major factors responsible for the reduction in
fish population in the Arun River Basin.
Figure 7.9: CIA Consultations with Fishing Communities
Source: ERM 2020
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Figure 7.10: Key Fishing Rivers and Nearby Communities
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Sport Fishing
Sport fishing has gained popularity in Nepal in recent years. Golden mahseer is the most commonly
sought sport-fish in Nepal. Sport fishermen also target copper mahseer, river catfish, mountain stream
trout, freshwater eel, mud eel, giant murrel, knife fish, feather back, and common and grass carp. In
Nepal, the best months for sport fishing are October to December and February to May. 13 Nepal
currently does not have any “catch and release” regulations .
A few sport fishing outfitters operate along the Koshi River and its tributaries, such as Nepal River
Runner, Nature Trail, and Adrift Adventures. According to the Nepal River Runner website, the outfitter
organizes a 5-day fishing trip in combination with rafting along Sunkoshi River, covering a distance of
over 270 km through the confluence of Arun and Tamor rivers.14 Adrift Adventure offers a combination
of rafting and trekking on the Arun River, in which participants can bring along a fishing rod or try local
methods of bamboo pole or a crude fish trap.15
River Rafting
At least four outfitters are currently providing rafting services on the Arun River: Nature Trail, Makalu
Adventure, Adventure Hub Nepal (AHN), and Swissa Rafting & Trekking Expeditions. According to the
website of Nature Trail, 16 this outfitter organizes a trek and rafting trip starting from Tumlingtar in
Sankhuwasabha. They offer a six-day rafting and kayaking, and claim that the lower Arun River is one
of the best rafting routes in Nepal, because of its turbulent water current and huge water volume, and
this route ends at Biratnagar. Adventure Hub Nepal provides a 16-day journey of a combination of
trekking and rafting with a total distance of 116 km. The trek starts from Tumlingtar and ends at Chatra
with the take-out point in Arun and Sun Koshi Rivers.17
During the CIA consultations, key informant interviews with members of the Majhi community revealed
that people like to do rafting, swimming, and other recreational activities in the Arun River near
Tumlingtar. This community used to provide boating services for the communities on both sides of the
river. However, since bridges have been constructed across the Arun River, the need for boating
services has stopped, and the community switched to fishing on a part time basis for income.
Sand and Gravel Extraction
CIA consultations with the Deputy Mayor, Khandbari Urban Municipality and the Coordinator of the
DCC, Sankhuwasabha, indicated that the crushing industry can take around 35 trucks of sand, stone,
and gravel per day from Shaba Khola, according to the agreement with the Khandbari Urban
Municipality. Crusher plants are not allowed in the Arun River, however, small scale mining for
households and other purposes is seen at some locations along the Arun River. While larger operations
require an IEE, small scale mining operations do not require any clearances, but are required to pay
royalty (fees assessed per truck) to the municipality.
Most gravel, sand and stone are extracted from Shaba Khola, Sishwa Khola, and Nepa Khola and partly
from Arun River. Materials extracted are usually used within the district, for instance, for road
construction.
During the CIA consultations, community members recognized that the extraction of sand, stone, gravel
has resulted in degradation and deterioration of fish habitat; consequently, there has been a significant
reduction in the fish population in the past 10 years.
13
https://www.fishinginnepal.com/fishing-in-nepal.php
14
https://www.nepalriverrunner.com/river/fishing-trip-sunkoshi-5-days/
15
https://www.adriftadventure.com/fishing-nepal/
16
https://www.naturetrail.com/arun-river-rafting/
17
https://adventurehubnepal.com/nepal/rafting-kayaking/rafting-kayaking-at-arun-gorges
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7.5.2 River Use for Domestic Purposes
The CIA consultations with the downstream communities found that the Arun River is an important
resource for communities in the Arun River Basin; for some, their livelihoods significantly depend on it.
The Lower Arun River is commonly used for irrigation purposes. A Solar Lift Drinking Water Scheme
provides drinking and irrigation water for communities in Boharatar, Katle Bhanjyang, and communities
in Tumlingtar by lifting water from Arun River and Shaba River. This scheme is particularly vital for
water-stressed communities for irrigation purposes and it has enabled an increase in agricultural
activities in dry areas, according to consultations with the community in Boharatar and Katle
Bhanjhyang.
The situation is different in the Upper Arun River, where relatively few people use the river for potable
water, fishing, or irrigation because of difficulties in accessing the river as a result of the difficult terrain,
but many (87%) use it for religious and other purposes.
7.5.3 Irrigation
Irrigated land comprises 47% of the agricultural land in the mountains of Sankhuwasabha District, and
28% in the hill district of Dhankuta (ICIMOD 2009) The irrigation sources for these districts tend to be
perennial and seasonal streams, rather than the Arun River (Table 7.17).
Table 7.17: Irrigation Sources
District Irrigated Land of Land Irrigated by Sources (%)
Total Agriculture Tube Well Perennial Seasonal Pond/Well Other
Land (%)
Dhankuta 28 0.7 45 49 0.7 2.8
Sankhuwasabha 47 0.3 15 74 2.6 6.5
According to the CIA consultation with the Water Source and Divisional Irrigation Officer of
Sankhuwasabha, the organization is providing surface irrigation to 821 ha of farmland from Malta Khola,
Hewa Khola, Hanchuwa Khola, Pantha Khola, and Neguwa Khola, which are tributaries of the Shaba
Khola and Arun River. Irrigation and drinking water are also provided by modern irrigation schemes
from Shaba Khola and Arun River. Modern irrigation schemes cover 106.5 ha of land in the district.
Farmers are using irrigation to cultivate crops (paddy, maize, white, potato) and vegetables. Surface
irrigation is specifically used to grow mustard, wheat, potato (winter crops), paddy, millet, and maize
(summer crops). In the Upper Arun River valley, most of the farmers grow cardamom in wet land, which
typically requires irrigation.
7.6 VEC: Settlement
7.6.1 Overview
The settlement VEC examines settlement patterns within the Nepal portion of the Arun River Basin. As
such, this section summarizes the historical settlement patterns based on the 2009 –2018 LULC
assessment of the Arun River Basin, and discusses associated drivers/effects of these movements
including commerce and industry, land ownership and housing, and public infrastructure.
7.6.2 Settlement Patterns in the Arun River Basin
Settlements in the Nepal portion of the Arun River Basin increased by 60% (from 47 km2 to 116 km2)
between 2009 and 2018 – although settlement land accounts for only for 2% of the Arun River Basin in
2018. Settlement was the fastest changing land class during this period, which had a gain rate of 22
km2 per year. As shown in Figure 7.11, settlement clusters have grown along rivers and roads,
particularly within the lower elevated regions of the Arun River Basin, between 2009 and 2018.
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There is a historical trend of people in the eastern region migrating from the hills to the Terai. There are
scattered settlements in the upper region of the Arun River Basin which have not been connected to
the region’s road network, which is changing due to construction of the North-South Highway.
Figure 7.11: Settlement LULC Change in the Arun River Basin from 2009–2018
Source ERM 2020
7.6.3 Historical Migration
The most fundamental changes to the Koshi Hill’s demography took place in the late 1950s , when there
was a significant movement of people from the eastern hills to the Terai after the eradication of malaria
and the expansion of farmlands and employment opportunities. The Census shows that migration
steadily rose until 2001, after which there was a dramatic acceleration within the Koshi Hills and
nationally. In 1981, the absent population in the Koshi Hills totaled about 20,100 (3.7% of total
population); by 2011, it had sharply increased to 51,318 (8.4% of total population), with the highest
portion recorded in Terhathum (9.5%) followed by Dhankuta (8.8%), Bhojpur (8.2%), and
Sankhuwasabha (7.6%) (CBS 2011). As shown in Table 7.18, the population in the three districts within
the Arun Basin (Sankhuwasabha, Bhojpur, and Dhankuta) increased between 1991 and 2001, and
decreased between 2001 and 2011.
Men (93%) are the main migrants from the Koshi Hills (CBS 2011), although, since 2001, there has
been a slight increase in the number of female migrants from 5.6% in 2001 to 7.0% in 2011. Historically,
a key feature of labour migration in Koshi Hills has been the spatial and social recruitment of young Rai
and Limbu ethnic groups into British and Indian regiments. The significantly higher salaries and
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pensions earned by recruits, coupled with the high degree of continuity in recruitment from specific
villages and families, have led to the creation of ‘new elites’ in the villages (Caplan 1995). This, also
has historical association with the flow of development assistance, primarily British aid, in the Koshi
Hills, such as the Dharan-Dhankuta Road, Pakhribas Agriculture Centre, Koshi Hill Area Rural
Development Project, and Nepal UK Community Forestry Project (Nickson 1992). However, recent
years have seen a rise in labour migration in the region, most particularly to Gulf countries, and a decline
in recruitment into the British and Indian army.
The destinations for labour migrants from Koshi Hills have expanded beyond the Terai and northern
Indian states, which were always the main destinations, to the Persian Gulf and South Asia. In 1991,
only 2% of the migrants from the Koshi Hills migrated to Persian Gulf, however, by 2001, this figure has
skyrocketed to 38% (CBS 1991; CBS 2001). This trend occurred in three of the Koshi Hills districts,
except Bhojpur where over 70% continued to go to India. The CIA downstream consultations with the
Kumul in Tumlingtar verified this fact, as one of community member stated that some of the young boys
in their community have migrated to Arabian countries or Malaysia for foreign employment.
This large scale labour migration has led to significant remittance flows back to the Koshi Hills. In 1971,
just over NRP 1 million in remittances entered the region; since then, remittances increased steadily,
reaching NPR 30 million by 1990 and nearly NPR 80 million by 1995. By 2005, the total value of
remittances back to the Koshi Hills had surpassed NPR 1 billion, having increased more than 10-fold in
just a decade.
The people that out-migrated were generally considered very poor, having fewer livelihood resources.
Gulf countries such as Saudi Arabia, Qatar, United Arab Emirates, and Malaysia are the major
destinations for foreign employment. Engagement in the Indian and British Army and Singapore Police
are popular especially among the aadibasi/janajati groups (particularly Rai and Limbu) in these districts.
The income derived from the salary and pension from the armed forces plays a significant role in the
local economy of these districts (KEL SA 2011).
Table 7.18: District Population in 1991, 2001, and 2011
Population Density
Area Population (persons)
District (person per km2)
(km2)
1991 2001 2011 1991 2001 2011
Sankhuwasabha 3,480 141,903 159,203 158,742 40.8 46.0 46.0
Bhojpur 1,507 198,784 203,018 182,459 131.9 135.0 121.0
Dhankuta 891 146,386 166,479 163,412 164.3 187.0 183.0
Source: CBS
7.6.4 Commerce and Industry
Off-farm Income Sources
Agriculture is, and has long been, the primary source of livelihood and income for households in the
Arun Basin (see Section 5.3.3). However, there has been a changing trend in the last decades as off-
farm (e.g., services, businesses, industries) earnings have gained importance in the region. The
sources of this growth in non-agricultural gross domestic product (GDP) are associated both with private
enterprise and the public sector, as well as development program growth. The trade and service sectors
in the Koshi Hills have also increased at an annual rate of 3.9% from 1971 to 2010. Moreover, trades
and services, as a percentage of total GDP, have risen from 22.6% in 1971 to 29.8% in 2010.
There has also been a significant increase in the number of cottage industries (economic activities
carried out in a person’s home) within the Koshi Hills (although the total number remains very low) from
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a handful in 1975 to over 1,700 by 2011. In 1975, families were only selling or bartering surplus products
at hāts (local makeshift market). This scenario has changed significantly due to the proliferation of
cottage and small enterprises and commercialized production. The utilization of family labour has,
however, remained dominant. Studies also indicate a gendered dimension to the cottage industries, as
production was, and continues to be, generally undertaken by women, the majority of whom are from
aadibasi/janajati communities.
The majority of the industries within the Koshi Hills are in textiles (47%), paper products (27%), and
food and beverages (20%), with most specializing in products that are chiefly based on local materials,
and crops that are indigenous to the districts. For example, tea estates are concentrated in Dhankuta
district, namely, Guranse Tea Estate, Kuwapani Tea Plantation, and Narayani Tea Plantation, while the
industries in Terhathum are focused on producing dhaka, a traditionally handloom-woven fabric that is
distinctive in its pattern and design. In Sankhuwasabha, the industries are based on fabric woven from
nettles (allo or Girardinia diversifolia) and handmade paper, while those in Bhojpur engage mainly in
paper production (CBS 2007).
The Arun-3 Hydropower Project EIA identified off-farm activities in the project area, such as the trading
of cardamom, hotel/lodges, trekking, and transportation based services. People also participate in hāts
for the trading of local produce and other goods for daily needs.
Findings from the CIA downstream consultations with communities in Khandbari Municipality and Shaba
Pokheri Rural Municipality were similar. Non-agricultural activities identified by the locals include
running hotels, tea stalls, jobs (such as teaching, office assistant), self-employment (driving vehicles
and tractors), or migration for foreign employment.
Market Centers
Trading is conducted through two types of markets in the Koshi Hills: (i) permanent market centers; and
(ii) local bazars known as hāts. There are permanent market centres with various hierarchical levels,
ranging from district headquarters to small centres in the Arun River Basin, of which most are connected
by roads. Hāts are crucial markets for rural villages, which are open all days of the week, selling local
products as well as imported goods. Hāts are by far the most important markets in terms of volume of
trade. The distribution of hāts exhibits a spatio-temporal pattern: they are held at different places, as
well as on different days of the week. There are 66 hāts across the Koshi Hills, approximately 1 hāt for
every 100 km2 (Figure 7.12). This density is changing due to improvements in roads and transport, the
commercialization of agricultural production, and increases in population density (Pradhan and Sharma
2017).
7.6.5 Land and Housing
In the Koshi Hills (Sankhuwasabha, Bhojpur, Dhankuta and Terhathum districts), approximately 88%
of the residents live in housing that they own, 8% live in rented accommodation, 3% live in “other”
housing, and 1% live in institutional housing (CBS 2011). There has been an increase in the number
of people residing in relatively “better housing” in the last two decades. More people are residing in
pakki houses (permanent house), although over half of the population continued to live in semi-pakki
houses (semi-permanent house with walls or roofs constructed using permanent materials), and just
fewer than 50% live in poor quality kachchi housing (built with temporary materials such as wooden
flakes, mud, straw, unbaked bricks, or bamboo).
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Figure 7.12: Market Centres in the Arun River Basin
Source: Pradhan and Sharma 2017
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7.6.6 Public Infrastructure
Roads
As discussed in Section 5.3.2, there are over 934 km of built roads in the Koshi Hills, which have
influenced settlement patterns within the Arun River Basin. Improved road connectivity is facilitating
trade in hāts and local permanent market centres. Highways have also opened up links for local produce
to be traded in larger cities of Dharan and Biratnagar in the Terai, as well as with other places across
the country, and also with India. There has been an increase in commercial agriculture and along the
roadsides.
Electricity
Although the number of households with access to grid electricity in the Koshi Hills is increasing (from
39% of households in 2001 to 53% in 2011), it is still much lower than the national average of 67%
(NPC and DFID 2013). There are small micro hydropower projects within the Project footprint. Electricity
is sourced from the micro-hydro projects in Sibrung, Namase, Hema, Rukma, and Chepuwa, among
others. These plants require regular maintenance and, thus, the use of solar home systems is also
prevalent in the region an alternative source. In areas where there are no such micro-hydro plants, the
use of solar is more prevalent. The major cooking fuel source is fuelwood, with 92.7% of households
depending on it (CBS 2011).
In the Koshi region, there has been very little hydropower energy development over the last decades.
The currently under-construction Arun-3 HEP was proposed in the 1990s. The project stalled due to
controversy regarding its environmental sustainability and economic viability, as well as equitable
benefit sharing of the local people. As of today, the four districts in the Koshi Hills only have a few small
scale and micro hydropower projects, which together provide energy to only a small proportion of the
population. The available electricity derives from the national grid and is generated elsewhere, and it is
largely confined to towns and larger settlement (NPC and DFID 2013).
Water Supply
In the Koshi Hills, about 72% of the households have access to tap and piped water. However, important
regional variations were detected: tap/piped water was available to over 80% of the population in
Dhankuta, but only about 67% of those in Sankhuwasabha and Bhojpur (CBS 2011). The sanitation
conditions have also improved considerably in the Koshi Hills, with Sankhuwasabha and Dhankuta
having approximately 77% of households with toilets, and Bhojpur with only 63% (CBS 2011).
Health Facilities
Health facilities in the Koshi Hills include hospitals, primary health care centers, health posts, and sub-
health posts. In 2004, the life expectancy of Koshi Hills residents was 65, showing an improvement from
63 in 1998. Despite a higher average life expectancy compared to the national average (55 years),
health services are considered poor in the Koshi Hills, due to the limited number of health personnel
and lack of convenient access to healthcare facilities (Pradhan and Sharma 2017).
7.6.7 Local Governance
Through the Constitution of Nepal (2015), Nepal restructured its governance system into three levels of
government: national, provincial, and local. The local government comprises municipalities and rural
municipalities. In Sankhuwasabha District, there are 10 municipalities/rural municipalities and 76 wards,
out of which 5 are rural municipalities (gaunpalika) and 5 are municipalities (nagarpalika).18 The ward
is the lowest administrative unit. Khandbari is Sankhuwasabha District’s headquarters and Hatiya is
Bhotkhola Rural Municipality’s headquarters. DCCs coordinate between the federal government offices,
provincial government offices, village bodies, and municipalities/rural municipalities within a district;
18
https://cbs.gov.np/wp-content/upLoads/2018/12/Population_Ward_Level_753_Local_Unit.pdf
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monitor development and construction work; manage natural disaster resilience; and issue working
procedures, directives, and standards within their jurisdiction.
The Constitution underpins the Government’s vision of protecting, promoting and using water resources
effectively. Water resources management and conservation are the jurisdiction of national government
as well as provincial governments. Watershed management, drinking water, and small hydro projects
fall within the purview of local governments.
In addition, there are a number of donor and multi-lateral agencies. Furthermore, each district has a
chamber of commerce and industry (CCI) that looks after business and industrial activities. Most of the
NGOs are working in forestry, drinking water and sanitation, women’s empowerment, and savings,
credit, and group mobilization. The NGOs working in these sectors have received support from different
national, foreign, and international agencies. Many decades ago user groups existed, which played a
role in local development in the Koshi Hills (Pradhan and Sharma 2017).
7.7 VEC: Social Cohesion
The World Bank defines social cohesion “as the glue that bonds society together, promoting harmony,
a sense of community, and a degree of commitment to promoting the common good. Beyond the social
relations that bridge ethnic and religious groups, vertical linkages in which state and market institutions
interact with communities and peoples can further cement the cohesiveness of a society if they are
inclusive, transparent, and accountable” (Colletta et al. 2001). As such, this VEC considers social
capital, social inclusion (vulnerable groups, indigenous communities and women), sense of place, and
cultural practices within the Nepal portion of the Arun River Basin, which are discussed below.
7.7.1 Social Capital
Social capital is understood as “the goodwill that is engendered by the fabric of social relations and that
can be mobilized to facilitate action” (McDougall and Banjade 2015). Given the limited size of the
villages, with approximately 20–30 households within each village, community dependency is high and,
thus, social capital plays a significant role. Through consultations, several incidences of close
community networks and interdependence were observed. As an example, when there is a death in a
family, the entire village participates in the final ritual. During the harvest season, communities take
turns to help each other with the fieldwork. Borrowing from close relatives and neighbors is one of the
common ways of borrowing within these villages.
7.7.2 Sense of Place and Cultural Practices
The natural environment is of significant cultural and spiritual importance to inhabitants of the Arun
River Basin. Forests and rivers are of particular importance to many indigenous communities in the
basin. Several communities (including Limbu, Magar, Gurung, Sherpa, and Rai) perform spiritual rituals
along the Arun River and its tributaries, according to the CIA consultations. The Deputy Mayor of
Khandbari Urban Municipality identified that different communities perform rituals by the river and in the
forests, mostly on the banks of Sabha Khola and Hewa Khola, and in Banduke, Maanebhanjyang, and
Mankamana Rivers. Community people from any caste and ethnicity make offerings to the gods during,
Naya Puja, Jangali Puja and Udhauali/Ubhauli (local festival), which are performed on the banks of
rivers or near their own houses. For instances, the Kumal, Rai, and Majhi used fish to offer/worship God
during Kul Puja (a yearly ritual specific to their community). Religious activities and festival celebrations
often take place at the confluence of Shaba Khola and Arun River, as well as at the confluence with the
Barun River at Maghi Mela in Triveni.
According to the CIA consultations, cremations are performed at many locations along the banks of the
Barun, Sabha, and Arun rivers by different communities, including the Kumal, Majhi, and Rai – for
example, at the confluence of the Barun and Upper Arun rivers, in Triveni (confluence of Sabha and
Arun rivers), and near the Manakamana Temple on the bank of the Arun River in Tumlingtar. The Rai
community have burial grounds in the hills.
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Moreover, a number of shrines, temples, and sacred places, which are common to all of the religions
and various ethnic groups, are situated along the riverbanks. The most important is Manakamana Mai,
on the left bank of the Arun immediately north of Tumlingtar. Every year during the winter month of
Magh (Jan-Feb), local people and others from surrounding districts, gather here to worship and
participate in the Mela, which is a continuation of the larger annual Barun Mela held upstream at the
Barun/Arun confluence.19
In addition, these communities usually have cultural and traditional practices that are both related and
non-related to their religions. According to the UAHEP ESIA social baseline survey, the main cultural
practices of the Rai ethnic group include traditional singing, wood craft, sewing, and the use of dhami
and jhakri (religious doctors). The Rai also celebrate the festivals of Dashain, Tihar, and Losar. The
Gurung ethnic group’s main cultural practices include traditional songs and dancing, wood craft, sewing,
and carpet making. Other customary and religious traditions practiced by Gurung include Bhumi Puja,
Dashain, and Tihar.
Detailed information about the tangible and intangible cultural heritage of ethnic groups in the Arun
River Basin, particularly in the UAHEP Project affected area, can be found in Section of the UAHEP
EIA.
7.7.3 Social Inclusion
Ensuring the inclusion of communities from different ethnic backgrounds, genders, and vulnerable
groups (both social and economic), as well as indigenous communities, is a critical element of social
cohesion.
Vulnerable Groups
Vulnerable groups are defined as disadvantaged people who are marginalized socially, economically,
or politically. This section provides an overview of the vulnerable groups in the Arun River Basin (Dalits,
women, and indigenous peoples).
Dalits
The National Dalit Commission in Nepal defines Dalits as “those communities who, by virtue of atrocities
of caste-based discrimination and untouchability, are most backward in social, economic, educational,
political and religious fields, and deprived of human dignity and social justice” (NDC 2008). The Dalit
community faces daily discrimination, with Action Aid Nepal estimating that Dalits face 205 forms of
discriminatory practices in their daily lives (KAHEP SA). These range from the denial of access to public
places, such as drinking water from public wells and entering sacred religious sites, to exclusion from
participating in democratic processes and leadership positions in organizations. While discrimination
and the untouchability system was abolished by the Constitution of 1963, and caste-based
discrimination was outlawed by the Caste Based Discrimination and Untouchability Act in 2011,
implementation, especially in rural and remote areas, continues to be a challenge.20 While communities
are not vocal about such discrimination, it was clearly evident in interactions with the communities
across several instances. One such example emerged from a consultation with the Dalit community in
Sibrung, where the consultation had to be conducted outside the residence, as Dalits were not allowed
inside.
Different development indicators show that Dalits are still lagging behind compared to other
communities in Nepal. While poverty has decreased among the Dalit population, the poverty rate is still
41%, against the national average of 25%. The literacy rate of Dalits is 34%, in contrast to the national
average of 54%. Their life expectancy is 50.8 years, whereas the national average is 59 years. This
19
https://www.eia.nl/docs/mer/diversen/pos_010-
03_nepal_arun_iii_hydroelectric_project_environmental_assessment_summary.pdf
20
https://idsn.org/wp-content/uploads/2018/07/CERD-Nepal-2018-alternative-report-Dalit-situation-.pdf
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gap has widened in 2011, compared to the 2001 census. The under-five mortality rate for Dalits is 90
per thousand, which is 32% higher than the national average of 68 per thousand.21
The Dalit population in Nepal is estimated at 13–14%, based on the 2011 census, although some Dalit
groups have estimated this number to be as high as 20–25%, taking into account that some Dalits may
be reluctant to identify themselves as Dalits for fear of persecution (IDSN 2008). While there have been
several methods to group Dalits, the National Dalit Commission has listed 671 Dalit surnames belonging
to 21 distinct Dalit sub-castes.
Within the Arun River Basin Districts, Dalit groups make up approximately 10% of the total population
(Table 7.19). Their primary sources of livelihood are wage labour work and some crafts and artisanal
work. While they practice similar religious observances as other Hindu groups, these are held in
separate areas. Additionally, unlike other ethnic groups, such as the Limbu and Rai, no natural
resources are specifically associated with Dalit communities (Kabeli Corridor Project Social Impact and
Management Report). Dalit land holdings are typically small and landlessness among Dalits is extreme.
The Arun-3 HEP Resettlement Action Plan indicates that Dalits own less than 0.5% of the land holdings
in the project area.
Compared with other vulnerable groups (indigenous people and women), Dalits are considered to be
the most marginalized group in the area. This is due in part to low literacy, landlessness, and historical
caste-discrimination (untouchability).
Women
The marginalization and vulnerability of women and girls is deeply engrained in traditional caste society.
Women in Nepali society continue to face obstacles to participate in the formal economy and gain
political representation. Even as they participate in the labour force, they are often not compensated for
the labour they expend in both farm and non-farm activities. Women have less access to public services
such as education and sanitation, and are more vulnerable to violence and abuse. While the female
literacy rate has increased, it is still behind men (44.5% female literacy rate vs. 71.6% male literacy).
Women account for approximately 53% of the population in all of the Arun River Basin districts. Women-
headed households22 account for an average of 28% in the area (which is higher than the national
average of 25.73%). Women also play a significant role in the livelihood pursuits of their families. When
the primary source of income is not agriculture and livestock – as in the case where there is income
from the foreign employment of male family members – they provide secondary sources. Women
pursue various forms of livelihood, such as daily wage labour, fishing, cattle rearing, government
service, small businesses (e.g., shops, tea stalls, and eateries), tea plantation work, other cash
cropping, and making/selling handicrafts made from bamboo. Women are also engaged in making dried
fish and selling them in the local markets and collecting wild vegetables, wild fruits, and herbs for
livelihoods. This was confirmed by the CIA consultations.
The prevalence of traditional gender roles was observed during consultations with the communities in
Barhabishe Bazar, Boharatar, and Kumal Gaun. For example, fishing is considered a traditionally male
profession, in which women do not partake. The Deputy Mayor of Khandbari Urban Municipality
strengthened the fact that Nepal remains a male-dominated society by explaining that women’s opinions
and experiences are not valued in the households nor in the workplace. Gender roles were found to be
similar across different ethnic communities where women are primarily engaged in household work and
agriculture, and men are engaged in daily wage work and salaried jobs as well as agriculture. Moreover,
girls are also reported to fall victim to gender-based violence (GBV) and victimizing by their own family
members. Despite this, consultation with police officials in Hatiya suggests that the reporting of gender-
based violence is low among communities, undermining the significance of the issue.
Dalit women are also especially vulnerable and prone to social marginalization. Nepali law prohibits
marriage before the 20 years of age, and arranged marriage is practiced among different ethnicities
21
https://pdfs.semanticscholar.org/218f/61b06cec01333744bd4b4a312ea8121a86d9.pdf
22
A women/female-headed household is a household in which an adult female is the sole or main income provider.
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and communities. Arranged child marriage, which expose young girls and women to abuse, is still
common among Dalit communities. Dalit women commonly experience reproductive health issues,
such as prolapsed uterus, a result of young childbearing and poor nutrition. Consultations in Gadi
suggest that labor influx may increase the incidence of GBV if not managed properly. There were
reports of road contractors (from outside of the rural municipality/districts) marrying women from the
local communities, suggesting that such cases may result in trafficking in persons (TIP) cases if not
monitored carefully.
In addition, verbal abuse by contractors, including eve-teasing, 23 was reported in the open bathing
areas near the road construction sites. A contractor management plan designed to minimize such
impacts will need to be implemented.
Indigenous People (Aadibasi/Janajatis)
There are 22 indigenous peoples (aadibasi/janajatis) groups present in the districts in the Arun River
Basin, according to the 2011 Census (CBS 2011). These include 9 “highly marginalized”, 11
“marginalized”, 1 “endangered”, and 1 “advantaged” groups, according to NEFIN’s aadibasi/janajati
classification (Table 7.19). The classification is based on development indicators including literacy and
education, income, wealth, land holding and other assets.24
Table 7.19: Populations of Vulnerable Group in the Arun River Basin, by
District
Category Classification Sankhuwasabha (%) Bhojpur (%) Dhankuta (%)
Dalit Highly marginalized 10.34 9.86 7.40
Women
Women population (% of total population) 65.52 52.84 53.18
Dalit women (% of total Dalit population) 5.61 5.33 3.96
Indigenous women (% of total indigenous population) 43.45 33.17 34.86
Indigenous people (Aadibasi/Janajati) Groups
Rai Marginalized 19.54 54.21 32.96
Tamang Marginalized 19.13 16.02 10.79
Sherpa Marginalized 10.68 2.81 0.44
Limbu Marginalized 10.02 0.21 21.86
Gurung Marginalized 9.95 0.80 1.23
Newar Advanced 8.70 13.63 7.83
Yakkha Marginalized 8.30 0.23 5.10
Magar Marginalized 6.12 7.98 16.30
Bhote Highly marginalized 4.03 - 0.05
Kumal Marginalized 1.03 0.27 0.03
Lhomi Highly marginalized 1.00 0.02 -
Bhujel Marginalized 0.98 2.94 1.97
Majhi Highly marginalized 0.19 0.32 0.96
Tharu Marginalized 0.12 0.14 0.32
Topkegola Highly marginalized 0.08 - -
23
Eve-teasing refers to physical contact or harassment by a man to a woman in a public place.
24
https://www.ifad.org/documents/38714170/40224860/nepal_ctn.pdf/63df5831-28f8-4d0c-8338-ac2062c7fa24
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Category Classification Sankhuwasabha (%) Bhojpur (%) Dhankuta (%)
Sunuwar Marginalized 0.06 0.21 0.09
Bote Highly marginalized 0.04 - 0.01
Dhanuk Highly marginalized 0.02 0.01 0.04
Danuwar Highly marginalized 0.01 - -
Hayu Endangered - 0.01 -
Thami Highly marginalized - 0.18 -
Dhimal Highly marginalized - - 0.02
Total indigenous population 86,639 107,612 97,448
(% of total population) (68.13%) (58.98%) (59.63%)
Total population 127,461 182,459 163,412 7
Source: Census (CBS 2011)
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8. CUMULATIVE IMPACT ASSESSMENT
The focus of this cumulative impact assessment is to predict to what extent HEPs may contribute, in
combination with the other proposed projects and activities selected for this assessment, to cumulative
impacts on the selected VECs.
The significance of cumulative impacts is considered for each VEC – the significance is not evaluated
in terms of the magnitude of change, but in terms of VEC response and the resulting condition and
sustainability. The cumulative impact significance definitions used in this CIA are:
◼ Negligible – VEC would not experience noticeable changes
◼ Moderate – VEC would experience noticeable changes, but within natural variations
◼ Substantial – VEC would experience changes beyond natural variation, but within its range of
tolerance/resilience
◼ High – VEC would experience changes that would likely exceed its range of tolerance/resilience
and the viability of the VEC would be threatened
8.1 Overview of HEP Impacts
There are three primary categories of hydropower operating modes: run-of-river, peaking, and storage.
The important distinctions between the three modes are the amount of water stored, outflow, and
downstream flow effects, as summarized in Table 8.1.
Table 8.1: Hydropower Operating Modes
Operating Modes Relative Reservoir Size Outflow Downstream Flow Effects
Run-of-river Small Outflow = inflow Negligible
Peaking run-of-river Medium Large daily variation Potentially major negative
Peaking/Storage Large Relatively steady Positive and negative
Strict run-of-river projects do not regulate a river’s flows. Given that these projects do not store water,
they are typically considered to have fewer adverse impacts than peaking or diversion RoR projects.
PRoR projects (shown in Figure 8.1) provide daily or weekly regulation of flows by storing water in
small reservoirs behind the dam. Water is passed through dam turbines to maximize power generation
during times of peak energy demand. As such, peaking projects can result in sudden changes to a
river’s flow. By releasing large quantities of flows within the span of a few hours, peaking projects create
daily fluctuations between flood and drought that can wash away or disrupt fish breeding grounds and
aquatic biota. Unexpected dam releases can have detrimental impacts on people living downstream.
This is particularly the case when no advance warnings are issued prior to a release.
In a diversion RoR project, a portion of the river is diverted through surface or underground tunnels
(penstock) that connect to a downstream powerhouse. A small dam, or weir, is typically constructed to
ensure that enough water enters the penstock. Water from the penstock is run through turbines then
returned to the river. Long stretches of the river are often dewatered due to these types of projects,
turning the river into a series of pools and tunnels throughout the year. River diversions can also result
in changes in water temperature, velocity, and depth.
The development of several projects, even strict RoR projects, in a series (or cascade) breaks a river’s
connectivity. Such cascades can result in impenetrable barriers to migratory fish or block sediment from
traveling downstream. The blocking of sediment flow can negatively impact ecosystems and the fertility
of downstream floodplains. A schematic of a typical hydropower project and key environmental and
social impacts is shown in Figure 8.2.
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Figure 8.1: General Characteristics of Peaking HEPs
Figure 8.2: Schematic of a Typical HEP and Key Environmental and
Social Impacts
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8.2 Cumulative Impacts on VEC: Natural Forest Integrity
Approximately 66% of the Arun Basin is covered by forest land (Section 7.1.12) – which is of high
importance to maintain ecosystem services and to communities and species and which depend on the
natural habitat.
8.2.1 Key Stressors and Impacts
Key stressors that result in forest loss and fragmentation in the Arun River Basin include:
◼ Hydropower development: Conversion of forest land for construction of HEP components and
associated facilities
◼ Road development: Conversion of forest land to construct new and expand existing roads and
increased access to forests
◼ Agriculture and settlement expansion: Conversion of forest land to develop and expand upon
existing agricultural land and settlements. Loss of forest cover will result in increased dependency
on the remaining forests for, e.g., NTFPs, building materials, and other ecosystem services.
◼ Climate change and natural hazards: Increased climate related disasters such as landslides and
floods in the future
The impact pathway schematic in Figure 8.3 summarizes how the aforementioned stressors, plus other
RFFAs, may affect natural forest integrity in the basin.
Figure 8.3: Cumulative Impact Pathway for VEC: Natural Forest Integrity
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8.2.2 Cumulative Impacts
Historical Forest Gain
According to LULC analysis conducted for this CIA, the forest land in the Arun Basin has marginally
increased (0.10%) between 2009 (3,376.23 ha) and 2018 (3,376.62 ha) (Figure 8.4). Gains to forest
land was observed in the mountainous north-eastern area of the basin adjacent to Taplejung District,
whereas the main loss of forest land was in the mountainous north-western area of Sankhuwasabha
District (in the MBNP) and in the southern reaches of the Arun Basin.
The conversion of barren land and agricultural land were the main contributors to forest land gains. The
increase in forest land is likely primarily due to the forest conversation efforts of community forestry,
leasehold forestry, and private forestry programs over barren land and grassland/shrubland.
Figure 8.4: Gains and Losses to Forest Land between 2009 and 2018
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Future Forest Loss
Forest clearance for the construction of RoR projects is relatively small, compared to projects with larger
physical footprints (such as those with large dams and reservoirs). For example, the 1,040 MW UAHEP,
473 MW Arun-4 HEP and 40 MW IKHPP would result in forest clearance of approximately 153,258 ha
and 11 ha, respectively.
In addition to the hydropower components, forest clearance is typically required for associated
transmission lines and access roads. In the case of the UAHEP, less than 6 km of transmission lines
would be needed to connect the project to the Arun Hub. In comparison, 310 km of transmission lines
(400 kV double-circuit) to connect Arun-3 HEP to the Muzaffarpur substation in India. Of the total length
of 310 km, 26 km of the line is situated in the Arun Basin – which results in approximately 97 ha of forest
clearance.
Of all the identified future developments in the Arun Basin, the most significant forest clearance would
result from the construction of the Sapta Koshi Project. The Sapta Koshi Project would inundate
approximately 4,618 ha of forest land across Bhojpur, Dhankuta, and Sankhuwasabha districts –
representing approximately 1.4% of the total forested area of the Arun Basin. Moreover, according to
Rai and Linkha (2020), the high-dammed reservoir over the steep and rugged topography would pose
risks of landslide and erosion, which could further exacerbate forest loss in the area.
For road developments, the direct impact area comprises a typical 30 m RoW. As such, the direct impact
of the 120 km North-South Koshi Highway RoW comprises 92 ha of forest land. Of the 120 km route,
108 km is situated in the MBNP (Section 8.3.2). Moreover, about 24 km of new roads would be needed
for each of the planned HEPs on the Arun River to enable access to the projects from existing roads –
which would result in an approximately 72 ha RoW (based on a 30 m RoW) per HEP.
In addition to direct land take, HEPs, transmission lines and access roads result in habitat
fragmentation. Such fragmentation can negatively impact fauna and flora populations and often
exacerbates existing ecological impacts. Edge effects also occur when two dissimilar areas or habitat
types are temporarily or permanently located immediately adjacent to one another. This phenomenon
commonly occurs in cleared areas adjacent to natural habitats, where changed moisture differentials
can cause impacts such as increased predator and hunter access, microclimate changes, and
increased erosion. Similar edge effects can also occur adjacent to reservoirs where standing water
environments occur adjacent to forested habitats. This can lead to temporary inundation and drying out
of the lake shores, impacting vegetation distribution and abundance.
Natural habitat adjacent to infrastructure, including access roads and transmission lines, will likely be
exposed to edge effects during construction and continue into operation. Edge effects will occur along
reservoir margins during operation, caused by submersion and temporary emergence and drying, as a
result of water releases to meet power generation requirements. This is likely to lead to a bare, un-
vegetated reservoir margin area between short- and longer-term high and low water levels.
Climate change further exacerbates the aforementioned impacts on forested areas, as the high
likelihood of stronger monsoons will increase the risk and impact of monsoon related disasters such as
landslides and floods in the future (Bharati 2019).
Shown in Table 8.2 are land clearance approximations per type of development in the Arun River Basin.
The following RoW assumptions have been applied: 46 m for 400 kV transmission lines, 34 m for 220
kV transmissions lines, 30 m for access roads, and 50 m for the Num-Kimathanka Road. As land
clearance details (e.g., size and land type) are not currently available for all of the planned hydropower
developments, certain assumptions were applied: i.e., for Arun-4 and Lower Arun HEPs – 0.55 ha of
forest clearance per MW has been assumed, and for Kimathanka Arun HEP a 24 km access road has
been assumed.
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Table 8.2: Forest Land Clearance per Development in the Arun Basin
Land Required per Development in the Arun Basin (ha)
Development HEP Transmission Lines Roads RoW Total
Components RoW
Hydropower projects in Arun Basin (under-construction and planned)
Kimathanka Arun 490 67 50** 607
UAHEP 153 20 30 203
Arun-4 258* 49 49 356
Arun-3 94 97 56 247
Lower Arun 257* 11 50 318
IKHPP 11 3 17 31
Sub-total 1,263 247 252 1,762
Sapta Koshi Project 4,618 Not available Not available 4,618
Num-Kimathanka Road (North-South Highway) 92 92
Total estimated forest 5,881 247 344 6,472
clearance
% of total forest area in 1.8% 0.1% 0.1% 1.7%
the Arun Basin
Notes: * Assumed 0.55 ha of forest clearance per MW; ** Assumed 24 km access road
Source: ERM 2019
8.2.3 Summary of Cumulative Impacts
Cumulatively, the impacts of the planned HEPs, road developments, transmission lines, and other
anthropogenic activities within the next 10 years on forest loss and fragmentation in the middle Arun
Basin are considered to be of Moderate Significance. A road network already exists in this area and
forest cover has remained fairly consistent between 2009 and 2018. However, there are a number of
planned HEPs that would result in forest loss and fragmentation, particularly for the construction of
access roads and transmission lines.
Due to the high number of planned large HEPs and the development of the Num-Kimathanka Road,
the cumulative impacts on forest loss and fragmentation in the upper Arun Basin are of High
Significance. The cumulative impacts on the MBNP, which is situated in the northwest of the Arun Bain
and covering approximately 45% of the Basin, is examined separately in Section 8.4.
The cumulative impacts on forest loss and fragmentation in the lower Arun Basin are of High
Significance. The most significant impact would be from the Sapta Koshi Project, which would inundate
4,618 ha of forest land near the lower Arun River.
8.3 Cumulative Impacts on VEC: Makalu Barun National Park
As discussed in Section 7.2, the MBNP is a nationally and internationally recognized protected area
classified as an IBA. In addition to being a key biodiversity area, local households greatly depend upon
the diverse national resources within the park’s Buffer Zone to maintain livelihoods and household
sustenance.
8.3.1 Key Stressors and Impacts
Key stressors and impacts on the MBNP include:
◼ Hydropower developments: Loss of habitat associated with land clearing for infrastructure
development (including habitat inundated by creation of the reservoir following impoundment),
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disturbance and/or displacement of fauna, barrier creation, fragmentation and edge effects, habitat
degradation, transmission strikes and other mortality events
◼ Forest resource collection and agricultural practices : There is a high dependency on forest
resources from local and slash and burn cultivation and overgrazing further threatens forest land.
◼ Road developments: Increased access will exacerbate pressure on the forest resources, mortality
events associated with vehicle strikes, land clearing, and increased hunting and poaching.
◼ Climate change and natural hazards, particularly GLOFs: Mortality events and loss of habitat,
resulting in impacts on taxa supported by those habitats and associated ecosystem services
The impact pathway schematic in Figure 8.5 summarizes how the aforementioned stressors affect
biodiversity and ecosystem services in the MBNP.
Figure 8.5: Cumulative Impact Pathway for VEC: Makalu Barun National Park
Source: ERM 2020
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8.3.2 Cumulative Impacts
Hydropower Projects
There are several HEPs planned on the main stem along and tributaries within the MBNP. It is
impossible for any hydropower project on the main Upper Arun River to avoid impacting on the MBNP,
as the park boundary extends along the centerline of the river from below the Arun-3 HEP, all the way
to the border with China.
As summarized in Table 8.3, there are five HEPs planned on the Upper Arun River in the MBNP:
Kimathanka Arun, UAHEP, Arun-3, Arun-4, and Lower Arun. These projects will directly impact only on
the MBNP Buffer Zone, not the Core Area. On the tributaries within the MBNP Core Area three HEPs
are planned: Apsuwa I, Upper Isuwa, and Lower Barun, and six planned HEPs within the MBNP Buffer
Zone: Upper Apsuwa, Isuwa, Lower Isuwa, Kasuwa, Upper Sankhuwa Khola, and Sankhuwa Khola.
These hydropower schemes will result in barriers to the movement of fauna species; disturbance to
fauna behaviors; habitat degradation, fragmentation, and loss; bird strikes from transmission lines;
fauna mortality from vegetation clearing activities; and induced impacts from increased access. The
main stem projects on the Upper Arun River (main stem) would result in an estimated 327–490 ha of
land conversion in the MBNP Buffer Zone. The tributary projects in the MBNP Core Area would require
an estimated 267–397 ha, and the tributary projects in the MBNP Buffer Zone would require an
estimated 208–312 ha.
Table 8.3: HEPs planned in the MBNP
Hydropower Project Upper Arun River Tributaries in Tributaries in
in MBNP Buffer Zone MBNP Core Area MBNP Buffer Zone
Kimathanka Arun 450 MW PRoR
UAHEP 1,040 MW PRoR
Arun-3 900 MW PRoR
Arun-4 473 MW RoR
Lower Arun 470 MW PRoR
Apsuwa I 400 MW
Upper Isuwa 24.3 MW
Lower Barun 132 MW
Upper Apsuwa 24.6 MW
Isuwa 97.3 MW
Lower Isuwa 37.7 MW
Kasuwa 9.2 MW
Upper Sankhuwa Khola 24 MW
Sankhuwa Khola 41.06 MW
Road Developments
Road developments (specifically the Num-Kimathanka Road and access roads to reach the planned
HEPs) would result in similar habitat degradation, fragmentation, and loss. New access can also result
in indirect impacts such as illegal logging, clearing, hunting, poaching, and collection of animal and plant
species, as well as vehicle strikes. A total of 108 km of the Num-Kimathanka Road passes through the
MBNP, requiring a 540 ha RoW and a 5,400 ha Zone of Influence. Moreover, the development of roads
to access the main stem HEPs would require approximately 32–47 ha of land for the RoWs, and the
tributary HEPs access road RoWs would require approximately 190–285 ha.
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Electricity Connectivity
To support the planned HEPs on the Upper Arun River a total of approximately 86–130 ha RoW would
be required for transmission lines in the MBNP Core Area and 81–122 ha would be required in the
MBNP Buffer Zone. In addition to habitat degradation, fragmentation, and loss, transmission line
projects would result in an increased frequency of bird-line collisions and electrocution.
The Arun Valley is a well-known migratory route for birds migrating through the Himalayas. The MBNP
in this regard could be a significant migration corridor for birds. Large bodied water birds perform north-
south migrations and are known to use this corridor. Also, important to note is that many large bodied
raptors not only migrate north-south, but also move east-west. Hence, north-south transmission lines
could also be a significant threat to these birds.
Other Anthropogenic Activities
Historically, agricultural practices such as slash and burn cultivation and overgrazing have resulted in
significant impacts on natural habitat in the MBNP and its Buffer Zone. Other anthropogenic activities
that may have a significant impact on forest land and species of conservation significance include those
that would convert or disrupt larger areas of natural habitat to other land uses (e.g., forest encroachment
for agricultural land and settlement expansion). As shown in Figure 8.6, there are 13 settlements located
in the MBNP Buffer Zone, at which agricultural land has encroached upon forested areas. Such habitat
loss and fragmentation poses threats to threatened and endemic species in the basin. Moreover, the
collection of forest resources is likely to intensify as population and settlement expansions increase
upon opening of the Num-Kimathanka Road and HEP access roads in the study. Table 8.4 summarizes
estimated land clearance within the MBNP.
Table 8.4: Estimated Land Clearance in the MBNP
Land Required per Development
Development HEP Transmission Roads
Total
Components Lines RoW RoW
Hydropower projects and associated facilities – on Upper Arun River in the MBNP Buffer Zone
Kimathanka Arun
UAHEP
Arun-4 HEP* 327–490 ha 28–42 ha 32–47 ha 356–580 ha
Arun-3
Lower Arun HEP*
Hydropower projects and associated facilities – on tributaries within the MBNP Core Area
Apsuwa I
Upper Isuwa* 265–397 ha 86–130 ha 115–173 ha 466–700 ha
Lower Barun
Hydropower projects and associated facilities – on tributaries within the MBNP Buffer Zone
Upper Apsuwa*
Isuwa Khola*
Lower Isuwa Khola*
Kasuwa Khola* 208–312 ha 53–80 ha 75–112 ha 336–504 ha
Upper Sankhuwa Khola*
Sankhuwa Khola
Num-Kimathanka Road
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Total estimated clearance 800–1,200 ha 167–251 ha 762–873 ha 1,729–2,324 ha
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Figure 8.6: Developments Planned in the MBNP
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GLOFs
The MBNP is also at risk of climate change associated natural hazards including flooding, GLOF,
wildfires, and landslides. GLOF events may increase over the coming years as the trends of
temperature and precipitation in the region are predicted to increase in the future. There are three glacial
lakes located in the MBNP: Langmale, Barun, and Lower Barun (Figure 8.7). As discussed in Section
5.3.3, the Langmale is a high volume moraine-dammed lake, which has a high outburst probability.
Should an outburst occur on one of these lakes, UAHEP would likely be impacted, grazing areas
(kharka) would also be flooded, and bridges, trails and homes would be destroyed – as was the case
on April 20, 2017 when a Langmale GLOF impacted 0.76 km2 of agricultural land, 33 buildings, and
four bridges.
Figure 8.7: Glacial Lakes in the MBNP
Source: Byers et al. 2019
Ecosystem Services
Traditional and subsistence use of forest resources are allowed in Buffer Zone areas of the MBNP,
such as cattle grazing and collecting fuelwood, timber, and non-timber forest products, with the
permission of the chief conservation officer of MBNP. As such, in addition to the loss of biodiversity
value, developments in the MBNP will result in the loss of aforementioned forest resource use (also
referred to as provisioning ecosystem services). Using the total economic value of forest ecosystem
services (Section 7.1.4), the loss of these resources are estimated at NPR 52–70 million (US$441,000–
594,000) per year.
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8.3.3 Summary of Cumulative Impacts
Cumulatively, the impacts from the planned HEPs, road developments, transmission lines and other
anthropogenic activities within the next 10 years – coupled with an increase in natural hazards such
as GLOFs – to the MBNP are considered to be of High Significance.
8.4 Cumulative Impacts on VEC: Water Resources
8.4.1 Key Stressors and Impacts
Key stressors and impacts on water quality and flows in the Arun River Basin include:
◼ Existing and planned HEPs: Could result in flow regime changes and unmanaged domestic waste
due to the presence of workforce could affect water quality
◼ Sand and gravel mining: Could impact upon water quality from increased turbidity and suspended
soils, and oil spills or leakages from the excavation machinery
◼ Village and settlement development: Could negatively impact on water quality from increased litter
and surface pollution
◼ Road developments: Could cause erosion and sedimentation, resulting in water quality degradation
◼ Forestry and agricultural development: Could result in land clearance and agricultural runoff
◼ Climate change and natural hazards (e.g., landslides): Could affect water flows
8.4.2 Cumulative Impacts
The Arun River is currently free flowing along its entire length, however, within Nepal, the Arun-3 HEP
is under construction, four other main stem dams are proposed along its length, and the Sapta Koshi
High Dam multi-purpose project is located downstream, but would flood the lower portion of the Arun
River. These projects would substantially transform the Arun River from a natural free flowing river to a
series of dams and river sections subject to flooding (reservoir), reduced flows (diversion reaches), or
water level fluctuations (as a result of peaking operations at four of the hydropower projects). As Figure
5.1 indicates, flow in essentially the entire length of the Arun River in Nepal will be affected.
Of the approximately 175 km of river from the border with China to the proposed location of the Sapta
Koshi Dam, the entire Arun River within Nepal (and a small portion of the Sapta Koshi River) would be
converted as follows:
◼ Flooded river segment (i.e., reservoir) – ~98 km
◼ Reduce flow river segment (i.e., diversion reach) – ~73 km
◼ River segment subject to water level/flow fluctuations (i.e., due to peaking) – ~4 km
◼ Free-flowing river segment – 0 km
Further, as indicated in Table 6.3, there are several existing and many proposed hydropower projects
on tributaries of the Arun River. Most of these are small and true RoR operations. Nevertheless, on a
smaller scale, many of the tributaries to the Arun River would also be modified into a series of reservoirs
and reduced flow diversion reaches.
The overall cumulative effect of the proposed hydropower projects on natural flow in the Arun River will
be of High Significance.
These changes in flow conditions will affect the physical characteristics, biological conditions, and social
uses of the river. These effects are discussed below.
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Physical Characteristics
The effects of hydropower projects on flow can, in turn, affect the physical characteristics of a river,
including water quality, geomorphology, and sediment transport.
River Water Quality
In terms of water quality, the major concerns typically relate to temperature, thermal stratification,
dissolved oxygen, and the potential for reservoir eutrophication. For the Arun River, these risks are low
for the following reasons
◼ Reservoir water temperature and potential for stratification – The proposed main stem dams all
have relatively small reservoirs (with the exception of the downstream Sapta Koshi High Dam),
which, combined with the river’s relatively high flow even during the dry season, results in a very
short residence time for all of these reservoirs (maximum worst case residence time of
approximately 60 hours during the annual low flow month [January] at the Arun-3 HEP), which
poses little risk of reservoir thermal stratification.
◼ Dissolved oxygen – Colder water can absorb more oxygen, and the Arun River’s high gradient
combines to result in naturally high dissolved oxygen concentrations in the river. Further, the very
short residence time for all of these reservoirs results in little risk of low dissolved oxygen
conditions.
◼ Reservoir eutrophication – As indicated above, the relatively short residence time in all of the main
stem reservoirs, and relatively low nutrient concentrations in the river because of the low population
density within the river basin, result in little risk of reservoir stratification or associated
eutrophication.
The provision of environmental flows can help to mitigate these impacts to some extent. The overall
cumulative effect on river water quality is considered to be of Moderate Significance, with the more
significant impacts likely occurring in the large Sapta Koshi reservoir.
Geomorphology
Hydropower projects create different geomorphology risks in the reservoir, diversion reach, and reach
downstream from peaking powerhouses, as well as for road and transmission line construction.
◼ Reservoir area – Reservoir inundation can destabilize slopes along the reservoir margins,
especially for the four main stem hydropower projects that are proposed as having PRoR
operations, where reservoir water levels fluctuate by 10 to 15 m. These water level fluctuations can
destabilize adjoining slopes and increase the risk of landslides. All of these hydropower projects,
but especially the four PRoR projects, should carefully evaluate slope stability along the reservoir
margins and, if appropriate, establish maximum drawdown rates to manage slope stability risk.
◼ Diversion reach – In the diversion reach, the reduction in flow for most of the year will likely result
in the narrowing of the river channel, as the rivers adjusts to a new flow equilibrium, and woody
vegetation will start encroaching on the margins of the channel.
◼ Downstream reach – The reaches downstream from PRoR operation mode powerhouses will be
subject to fluctuation in water levels, velocities, and wetted area as the projects alternate between
peaking and non-peaking operations. This will reduce the ecological value of the portion of the
stream channel that is subject to the alternating wet and dry periods.
◼ Road and transmission line construction – Much of the Nepal portion of the river basin, but
especially the portion upstream from Khandbari, has very rugged terrain and steep slopes. The
construction of roads and transmission lines can destabilize these slopes across a large area.
Appropriate siting of these facilities, prohibiting side casting, and maintaining vegetation within the
transmission line RoW can all help to minimize the risk of landslides from these facilities.
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The provision of environmental flows can help to mitigate these impacts to some extent. The overall
cumulative effect on geomorphology is considered to be of Moderate Significance.
Sediment Transport
The Arun River transports a naturally large sediment load, as a result of the glaciers in the river’s
headwaters. Management of this sediment is critical, both to maintain the life expectancy and
sustainability of the hydropower projects, as well as to minimize impacts on stream channel
geomorphology and aquatic habitat.
The multiple hydropower projects along the mainstem of the Arun River will affect natural sediment
transport, with more coarse sediments settling out in the project reservoirs. Details of the sediment
management strategy for several of the proposed mainstem hydropower projects is not available, but
the five most upstream mainstem projects all have quite short reservoirs (0.5–5 km in length) and should
be able to maintain a relatively natural sediment transport system with monsoon season sediment
flushing. The Sapta Koshi HEP would have a much longer reservoir (~70 km), which would likely result
in significant sediment deposition and much more significant sediment management challenges.
The overall cumulative impact on sediment transport is considered Moderate in the Upper Arun River
and High in the Lower Arun River.
Biological Conditions
The impacts of changes in hydrological regimes on fish and aquatic habitat are discussed in detail in
Section 8.5.
Social Uses of the River
At various locations along the Arun River, the river is used for subsistence, recreational, and commercial
fishing; irrigation; recreational boating; and cultural practices (e.g., cremations). The river is not used in
any meaningful way for water supply or navigation purposes and it is unlikely that the proposed
development activities would have any adverse effect on future use of the river for these purposes. The
potential cumulative impacts on fishing, irrigation, and recreational boating along the Arun River are
discussed in Section 8.6.
8.5 Cumulative Impacts on VEC: Fish and Aquatic Habitat
8.5.1 Key Stressors and Impacts
Key stressors and impacts on fish species and habitat in the Arun River Basin include:
◼ Hydropower projects: Could result in altered hydrological regimes, water quality degradation, loss
of aquatic habitat from reservoir development and water diversion, and barrier effects
◼ Road development: Could result in soil erosion into rivers, which could then likely result in a
significant increase in total dissolved solid levels which degrades aquatic habitats
◼ Climate change: Could lead to changing patterns of rainfall (both higher and lower) within and
between seasons, thereby affecting river flow
The impact pathway schematic in Figure 8.8 summarizes how the aforementioned stressors affect
aquatic species and habitats in the basin.
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Figure 8.8: Cumulative Impact Pathway for VEC: Aquatic Species and Habitat
8.5.2 Cumulative Impacts
Hydropower projects will change several characteristics of aquatic habitats in the basin – including
water depth, channel width, flow velocity, substrate/sediment characteristics, and potentially habitat
connectivity. Each of these changes will have effects on aquatic community composition and diversity
within the basin, as summarized in this section.
Species gradient along a river section is an important issue when assessing the impacts of hydropower
projects in Nepal. Usually when moving upstream in a river the number of species decrease as a
function of the physical properties of the river. Exact species gradients for the Arun River Basin are
currently not available, as such, environmental monitoring connected to Arun-3 and UAHEP show a
decreasing species diversity when moving upstream from 700 masl (downstream Arun-3 dam site) and
up to 1,600 masl (dam site of UAHEP). Other documents describing the fish biodiversity in Arun show
high fish biodiversity in lower parts of the river. Based on this knowledge the species list of 45 species
are prepared and seven target species were selected according to the target species criteria: Anguilla
bengalensis (bam), Tor putitora (golden mahseer), Labeo dero (gardi), Neolissochilus hexagonolepis
(katle), Glyptosternum blythi (telkabre), Schizothorax richardsonii (asala) and Psilorhynchoides
pseudecheneis (titae).
It is to be noted that the maps presented in this CIA showing the target species distribution are
indicative, reliant on limited survey data and the review of secondary information. Distributions are likely
to change with comprehensive surveys.
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Generally, many long distance migratory fish (e.g., Tor sp.) use the tributaries of the Arun River and its
confluence points with tributaries for spawning, as well as rearing of fries and fingerlings. Mid-migratory
fish, specifically Labeo dero (gardi), Schizothorax progastus and richardsonii (chuche and butche
asala), and Neolissocheilus hexagonolepis (katle) migrate to the tributaries during the spring and
monsoon season.
As detailed in Section 7.4.3, a DEM of the basin was used to predict migratory fish species distributions,
based on predicted temperature tolerance for migratory species. For each zone and from their
accompanying ecological attributes for fish life-histories, the cumulative impacts were then assessed,
as described below.
Barrier Effects
The most significant cumulative impacts arise from the barrier effect of additional dams. Dams without
fish passages will impede the migration of fish attempting to access foraging sites and spawning sites,
and stop seasonal movements due to changes in water temperature and flow. Most of the mainstem
Arun River dams will likely be quite high (e.g., Arun-3 HEP is 68 m and UAHEP will be 91 m), which
limit the potential effectiveness of fish passage facilities.
There are likely more than 20 tributaries that might offer spawning habitats. The non-snow or glacier
fed tributaries (i.e., cool water tributaries) usually show higher water temperatures than the main stem
of the Arun River (i.e., cold water). When water temperatures are too low for spawning in the main river,
the warmer tributaries offer better habitat for spawning and bio-production, which is a function of
temperature and of sediment load. An example is the common snow trout, which spawns naturally in
clear water on gravelly/stony grounds or on fine pebbles at 1 –3 m depth, and these conditions are often
likely in tributaries (Shrestha and Khanna 1976).
Several of the large main-stem hydropower projects along the Arun River are proposed with PRoR
operations. When peaking, these projects have the potential for interrupting habitat connectivity
between the Arun River and tributaries. Peaking operations will likely occur for most of these projects
during the dry season from October to May, which includes the spring spawning migration period, and
have the potential to disrupt fish access to spawning areas in tributaries. Fish connectivity between the
Arun River and the tributaries must be maintained, especially during the spawning season, to support
fish access to important spawning grounds. Ikhuwa Khola and Leksuwa Khola are two key spawning
tributaries that may be affected by the UAHEP PRoR operations. Maintaining this habitat connectivity
is critical in the segment of the Arun River between the Arun-3 and UAHEP dams to maintain a naturally
reproducing native fish population.
A good productive substratum Is composed of gravel and stones that give good shelter for the fish.
Another important quality of the tributaries is the flow conditions during the dry season. Temporary dry
out or very low flow give also limited ecological value.
Dams will impede access to these tributaries by either being in the main stem and impeding entry into
the upstream tributaries or, if in tributaries, impeding access to desirable habitats further upstream in
the tributaries.
Facilitating downstream migration for both adult fish and fry is just as important as for upstream
migration. Fish passing through hydropower turbines usually have high mortality, and the mortality
increases when the body length of the fish increases.
The dam for the Arun-3 HEP is under construction and blocks the river at approximately 800 masl.
There is no fish passage planned and with a head race tunnel of 11.7 km the dewatered section in Arun
river is approximately 20 km.
There is insufficient data on what mid- and long-distance migrating fish species are passing through the
Arun-3 dam site, but the dam is situated at an elevation that usually still has several species present,
potentially including the golden mahseer, although there is only one 15-year old record of golden
mahseer being observed upstream from the Arun-3 dam site. The Arun-3 HPP will prevent any long
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migrating and mid distance migrating fish species from reaching spawning areas upstream from the
dam site, and also probably change the possible utilization of the river and tributaries between the dam
and the tail race entry in the river due to low flow.
The general impacts of these type of dams lead to loss of spawning and nursing areas upstream from
the dam that will affect the recruitment by fish fry to the ecosystem downstream from the dam. This
blockage of the ecosystem services may have a long-term effect on the species composition, population
sizes, and biomass production in the river system.
It is not possible to mitigate these losses of upstream migrating biomass by establishing hatcheries, as
hatcheries will typically result in the loss of genetic vigor and diversity within the native fish stocks. The
only possibility is to establish a fish population that can utilize the local bio-production by using stocking
by fry from hatcheries as mitigating measure upstream from the dam. If fish from a hatchery are to be
part of the mitigating strategy to strengthen the downstream fish populations, species selected, size of
fish fry, and when stocking shall be done are important factors.
Flow in dewatered sections is crucial for fish to migrate. Small fish, such as stone carp (titae) and
common snow trout (asala), need less flow than larger fish, such as golden mahseer. Flow may favor
some species and stop other species.
Table 8.5 provides the spawning potential for each of the zones in terms of number of suitable
tributaries. Suitability is assessed based on its potential for offering more favorable conditions. Table
8.5 also provides the rationale for suitability based on where information was available from secondary
literature sources. Given the lack of fish passage, at most, if not all, of the proposed main stem
hydropower dams, these projects will result in segmented populations of native fish, including mid-range
migrants who can tolerate cold water lentic (i.e., reservoir) conditions. In order to maintain genetic vigor
and naturally reproducing populations, preservation of important tributary spawning streams, such as
Ikhwua Khola located between Arun-3 HEP and Arun-4 dams, is critical.
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Table 8.5: Suitability of Spawning Potential for Tributaries in Temperature Zones
Tributary Suitability for Likely Cumulative Impacts from Barrier
Zone Rationale Reference
Spawning Effects
Cold Negligible in snow-and Tributaries such as the Chujung Monitoring results, Main Stem
Down to 800 masl glacier fed rivers and Khola upstream from UAHEP dam stakeholder consultations, Kimathanka
Moderate if warmer than main site in high elevation (confluence maps and Google Earth No fish passage, stop fish migration, low bio-
stem and in clear water above 1,700 masl) are snow fed pictures, expert production
tributaries and cold as the Arun River, and the consultations Small fish population, mostly resident
spawning potential is low. The Impacts: Moderate
Barun River is snow and glacier fed
and has also a waterfall close to the UAHEP
confluence with the Arun River. The No fish passage, stop fish migration, low bio-
fish species diversity is low with low production
population size. Small fish population, mostly resident
Impacts: Moderate
Tributaries such as Leksuwa Khola
and Ikhuwa Khola (High) Arun-4 HPP
(confluence 1,090 and 900 masl) No fish passage, fragmentation of river
are warmer than the main stem and habitat
with long periods of clear water. Block local fish migrations, IUCN listed fish
These kind of rivers are highly species
valuable as spawning and nursing With Arun-3 in operation the
habitats for several species that impacts are: Moderate
might include golden mahseer. It
only a few of these kind of “warm” Arun-3 HEP
rivers in the upper section of Arun No fish passage
river. IUCN endangered and vulnerable species,
good fish species diversity
Blockage of fish migrations
Under construction without fish passage, so
preventing upstream migration of long-range
migrants and some mid-range migrants
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Tributary Suitability for Likely Cumulative Impacts from Barrier
Zone Rationale Reference
Spawning Effects
Regional effects
Impacts: High
Tributaries
Cold tributaries as Chujung and Barun Khola
probably will have Negligible impacts from
downstream barriers due to low productivity
and restricted accessibility, small fish
populations. Barriers within these cold
tributaries probably also have Negligible
ecological impacts.
Leksuwa Khola, Ikhuwa Khola and Induwa
Khola are “warm” tributaries serving as
spawning and nursing habitats for the upper
Arun river section. Impeding access to these
tributaries by Arun-3 HEP will lead to impacts
on local, mid distance and long-distance
migrating fish species, and will probably
affect fish population far downstream in the
Arun River.
Impacts: High
Lower Barun Khola HEP
Natural waterfall stops fish migration (except
stone carp). Glacier fed and cold river.
Impacts: Negligible
Ikhuwa Khola HPP
Dam and low minimum flow impede fish
migration and affect the fish fry production,
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Tributary Suitability for Likely Cumulative Impacts from Barrier
Zone Rationale Reference
Spawning Effects
both for the in-river and the downstream
(Arun River) fish populations.
Effect will depend on fish passage and on
EFlow (10% not enough).
With 10% EFlow the impacts will be: High
Upper Ikhuwa Khola Small HEP,
High elevation, probably small fish
population.
Predicted impacts: Negligible
Cold-Cool Negligible in snow-and Rivers like Hingsa Khola (Kasuwa Monitoring results, Main Stem
800–400 masl glacier fed rivers and Khola) are not glacier and snow stakeholder and expert The Arun-3 dam blocks fish migration and
Moderate and High if warmer fed, but a landslide may give high consultations, maps and the minimum flow might alter the species
tributaries and in clear water temporary sediment load in the Google Earth pictures diversity along the 20 km long dewatered
perennial tributaries. lower section. If accessible for fish, section. The golden mahseer population and
This zone has high fish these tributaries with minimum flow several other species will be strongly
species diversity, including of > 1.5 m3/s might be a good affected.
IUCN listed species. spawning site for a nursing biotope. Impacts: High
In the upper part of the Cold-Cool
Zone, assumed High value. If peaking operations, the bio-production and
Isuwa Khola is glacier and snow species diversity downstream from the
fed and might be cold and with tailrace will be heavily affected.
Negligible-Moderate value as a Impacts: High
spawning habitat.
The Lower Arun dam and the dewatered
Apsuwa Khola is also glacier fed, section, without upstream and downstream
but with less ice than the Isuwa effective fish passages, might led to High
Khola, the river might be a clear level damage to the total fish population
water river and with a slightly higher including loss of species diversity and fish
temperature than the main stem. production, as well as fragmentation of the
fish community. This includes the IUCN
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Tributary Suitability for Likely Cumulative Impacts from Barrier
Zone Rationale Reference
Spawning Effects
High value as spawning and listed golden mahseer. The river in this
nursing habitat. section is highly productive.
Impacts: High
Sangkhuwa Khola has a large
catchment in lower altitudes and a Tributaries
relatively small part of the Kashuw Khola HEP in lower part of Hingsa
catchment is covered by ice and Khola might led to barrier effects for
snow, which means a warm migrating fish. Low EFlow (10%) might have
clearwater river with High value as the same effect. This river confluence might
spawning and nursing habitat, and be valuable for golden mahseer.
with high fish species diversity. Impacts: High
Isuwa Khola, is a cold or semi-cold river and
the Upper Isuwa HEP probably has a
Negligible effect on the fish population in the
downstream river system, while the local fish
population might suffer. The Isuwa Khola
HEP in lower part of the river might impede
fish migration and if there is an effect on the
confluence area with the Arun River the
project might affect the golden mahseer,
thereby resulting in High impacts, while if not
disturbing the confluence area, the impacts
are: Moderate.
Apsuwa I HEP
High elevation and probably low fish species
diversity and low fish production.
Predicted impacts: Negligible
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Tributary Suitability for Likely Cumulative Impacts from Barrier
Zone Rationale Reference
Spawning Effects
Upper Apsuwa HEP seems also to be in high
elevation, but the downstream dewatered
section might impede fish migration and
affect fish fry production, both for in-river and
downstream (Arun River) fish populations.
Effect depends on fish passage and EFlow
(10% not enough).
With 10% EFlow, impacts will be: Moderate.
Cool The tributaries in this section Rivers such as the Chirkhuwa Monitoring results, Main Stem
Downstream of 400 are all warm clearwater Khola, Sabha Khola, Hewa Khola, stakeholder and expert The Lower Arun PH indicates a long-
masl to the tributaries, which have High Nankuwa Khola, Piluwa Khola, and consultations, maps and dewatered section in this lower temperature
confluence with the value as spawning habitats. Pikhuwa Khola have good natural Google Earth pictures zone. Fish migration in this section depends
Koshi river The natural bottleneck for fish conditions that may serve on the EFlow during dry season. During
production is the flow during ecodynamic year-cycle processes, monsoon, the flow will probably be high
the dry season. In warm areas as well as high productivity and enough to serve the big fish species, such as
high temperatures and water High value as spawning areas and golden mahseer. Conditions with sufficient
quality might also play nursing rivers for a high number of EFlow result in impacts: Moderate.
important roles in defining the species including the golden During peaking operations, the bio-
species composition. mahseer. These rivers have production and species diversity in section
Low flows as 1 to 2 m3/s give catchments large enough to have downstream the tailrace will be heavily
high bio-production/m2, but perineal flows. affected. Impacts: High
these rivers are easy to
harvest and the fish Some of the smaller rivers might The Sapta Koshi Project will inundate a long
populations are often have very low flow during April due section of the Arun River, likely resulting in
decimated during low flow to no meltwater from the mountains. the loss of a significant amount of spawning
seasons by local fishermen, These rivers offer unstable habitat.
who in addition to traditional ecological conditions, but during
equipment are using both monsoon and late autumn might Tributaries
poison and electricity to catch provide spawning and short time Several of the tributaries that have an
and kill fish. This is also a nursing facilities for species that can assessed high ecological value due to
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Tributary Suitability for Likely Cumulative Impacts from Barrier
Zone Rationale Reference
Spawning Effects
serious problem along EFlow leave the rivers before low flow sufficient flows throughout the years cycle
sections in regulated rivers in season. have one or more hydropower projects
Nepal, and this anthropogenic The suitability for spawning might planned in the productive sections of the
activity makes the regulated be High, while the service as a rivers. Projects above water falls and in
rivers less suitable as nursing river might be Moderate. altitudes above 1,800 masl in this warm area
spawning and nursing have lower impacts than projects at lower
biotopes than rivers with altitudes. Impacts: Moderate
natural flow.
Most of these tributary hydropower projects
in lower altitudes may impede fish migration
and, if peaking operations are planned, the
total impact might be serious for the Arun
River catchment fish populations and
species diversity.
If upstream and downstream effective fish
passages are not built, a high number of
spawning areas and nursing areas may be
affected. Together, the power projects at
lower altitudes will probably have a High
impact. But, depending on EFlow and fish
passages, the impacts might be classified as
Moderate.
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Changes in Hydraulic/Hydrological Regimes by Reservoirs
The inundation of river segments for reservoirs could result in significant impacts on aquatic habitat.
These effects will be more significant for larger reservoirs and ones located in the lower portions of the
river basin (i.e., Sapta Koshi and Lower Arun), as warmer water temperatures and longer residence
times can result in reservoir stratification and reductions in dissolved oxygen. Species that needs fast
flowing well oxygenated waters (lotic species) will be impacted by inundation for reservoirs. Some
common species in the Arun River (e.g., common snow trout), however, can acclimate to reservoirs.
Fish that cannot tolerate reservoir conditions may move further upstream into tributaries and other lotic
habitats, which may result in increased competition and predation by individuals already occupying that
habitat. This is usually a short-term effect, until a new equilibrium is established. The reduction in lotic
habitats will likely result in a reduction in lotic bio-production.
Reservoirs can also provide habitat for exotic species, like the Chinese carp, which can proliferate and
may outcompete native species and become dominant in these altered natural habitats.
The loss of spawning habitats is especially crucial, although many fish in the Upper Arun River spawn
in the clear water tributaries rather than the cold, turbid, and high velocity Arun River. Hydropower
projects proposed on these clear water tributaries may have a disproportionate impact on fish in the
Arun River.
The main energy force in a river ecosystem is the input of organic matter. Both autochthonous and
allochthonous organic matter is relevant, where the allochthonous matter is usually the most important
source for bio-production. Construction of a reservoir reduces water velocity and both inorganic and
organic matter will be trapped in the reservoir. Entrapment of organic matter will result in considerably
increased potential for bio-production, compared to the average bio-production before the
impoundment. The section downstream from the reservoir will receive less organic energy for
ecosystem dynamic processes, which will suffer from the missing energy input.
If local fish species are able to utilize the positive bio-production qualities developed by the
impoundment, the fish production may increase substantially in the reservoir area. This is a function of
organic matter influx, temperature, water quality, and sediment load.
The glacier fed Arun River and its glacier fed tributaries carry a high sediment load and will likely have
a high sedimentation rate in the reservoir, which will result in depressed bio-production in the
impounded area compared to the bio-production in the free-flowing river section.
Table 8.6 provides the likely cumulative impacts of impoundment in the three zones.
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Table 8.6: Likely Cumulative Impacts from Impoundment in the Three Zones
Zone Suitability of Rationale Reference Likely Cumulative impacts From Impoundment
Main Stem and
Tributaries for
Lotic Species
Cold High This section of this river system is dominated by Aquatic biodiversity Main Stem
Down to 800 species developed to live in torrent fast flowing surveys conducted Relatively Negligible for each of the projects due to
masl rivers. Schizothorax sp. (snow trout), for this report, expert impoundments only to do short peaking operations. Four
Psilorhynchoides pseudecheneis (stone carp), and consultations HEP’s planned on the main stem:
some species of cat fish (such as Euchiloglanis − Kimathanka Arun HEP
hodgarti) dominate, and are all very strong − Upper Arun HEP
climbers. No species developed for lentic − Arun-4
environment are present. − Arun-3 (under construction)
The loss of the lotic bio-production area represents
relative low value due to small reservoirs (wetted area)
and low water temperatures.
More important in this glacier fed river is the effect on
the supply of allochthonous matter that will be trapped in
the reservoir and among the sediment. If not trapped
among sediments, the organic matter might bypass the
dewatered section. This organic matter is the key energy
for the river ecosystem. Due to relatively small reservoirs
and low temperatures each of the reservoirs do not lead
to substantial negative effects, but from four projects in
this upper section of Arun river the total impoundment
cumulative impact is assessed as High, because of the
little free-flowing river remaining between the dams.
In periods with low level sediment load, the effect on bio-
production in the reservoir will be Moderately positive
from a fish production perspective.
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Zone Suitability of Rationale Reference Likely Cumulative impacts From Impoundment
Main Stem and
Tributaries for
Lotic Species
Tributaries
The impacts will be Negligible, as most projects in this
zone are typical run of the river projects with minimal
impoundment. The organic matter effect is also
assessed as Negligible in the reservoirs.
Cold-Cool High In addition to the very strong climbers in the cold Aquatic biodiversity Main Stem
800–400 masl zone, there is a high number of lotic and oxygen surveys conducted Relatively Negligible as the project, Lower Arun HEP,
demanding species as Tor putitora, Neolissochilus for this report and has a relatively small impoundment area.
hexagonolepis, Labeo dero, and Angilla available literature,
bengalesis. All these are strong climbers and the expert consultations The loss of lotic bio-production area represents Low to
only species also adapted to life in lentic waters is Moderate impacts.
Anguilla bengalensis. More important, in this glacier fed river is the effect on
supply of allochthonous matter that will be trapped in the
The dams without a fish passage might prevent reservoir and among the sediment. If not trapped among
the eel from reaching the impoundments. sediments, the organic matter might bypass the
dewatered section. This organic matter is the key energy
In the lower part of this zone there might be to the river ecosystem.
increasing number of species, probably more than
20. But most of them adapted to fast flowing In periods with low level sediment load, the effect on bio-
rivers. production in the reservoir will be Moderately positive,
from a fish production perspective.
Tributaries
Impacts Negligible as most projects in this zone are
typical run of the river projects with minimal
impoundment, with some projects at high elevation and
some in a glacier fed tributary. The organic matter effect
is also assessed as Negligible.
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Zone Suitability of Rationale Reference Likely Cumulative impacts From Impoundment
Main Stem and
Tributaries for
Lotic Species
Cool Moderate In this zone the river slows down a bit, but still has Aquatic biodiversity Main Stem
400 masl and a high magnitude of stony river biotopes and high surveys conducted The Sapta Koshi would be by far the largest of the main
downstream velocity waters. for this report, stem reservoirs and will result in a significant loss of
available literature, spawning and lotic habitat, and a significant reduction in
The fish population in this zone consists of a high expert consultations the supply of allochthonous matter, which will be trapped
number of species, probably more than 40, with a in the reservoir and among the sediment. If not trapped
mixture between species adapted to life in fast among sediment, the organic matter might bypass the
flowing rivers, as well as generalists able to live in dewatered section. This organic matter is the key energy
different kinds of biotopes and also species to the river ecosystem.
adapted to more lentic river conditions.
Tributaries
At least 20 hydropower projects are planned in 7 of the
tributaries, which means a total massive hydropower
regulation in the watershed that even with small
impoundments and RoR power stations might give a
high cumulative effect especially concerning the impacts
on organic matter for the ecosystem budget.
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Low Flows in Dewatered Reaches
The Arun watercourse has a high number of planned hydropower projects in different ecological zones.
Depending on the decided EFlows for each HEP, the impacts may differ substantially in the dewatered
sections (Table 8.7). This amount of EFlow (as a percentage of river flow) required to maintain aquatic
habitat integrity varies based on several factors, including length of the sections, tributary inflow,
gradient, river geomorphology and cross-section, riverbed transect compositions, river substratum
(boulders, stones and gravel) and water temperatures. In the Upper Arun River, where the river is deeply
incised, less flow is required to maintain aquatic integrity. Farther downstream, where the river cross-
section widens, more flow is required to maintain aquatic integrity (e.g., water depths and velocities).
Table 8.7: Likely Cumulative Impacts from Low Flow in the Three Zones
Zone Likely cumulative Rationale
impacts of low flow
Cold Main Stem Main Stem
Down to The upper reaches of the Arun River connected to Kimathanka Arun HEP
◼ Negligible for
800 masl and Upper Arun HEP are situated in the cold, glacier fed river with high
Kimathanka
sediment load. The river has low bio-production and a small fish population
HEP and Upper
and a narrow relatively deeply incised river channel. The impacts here are
Arun HEP
less.
◼ Arun-3 – High Arun-3 has an EFlow of 10% of minimum monthly flow. The river has a
impacts on fish steep gradient and low flow might impede upstream migration before
species monsoon. In this zone, the water temperatures give good bio-production
migrating conditions, with fish species diversity of 20 or more species, including
upstream valuable species such as golden mahseer, copper mahseer, and different
before species of snow trout.
monsoon
During low flow season, wetted productive area will decrease and so will
◼ Arun-3 – bio-production and the fish production. Due to low flow, the harvesting of
Moderate fish will be far easier than in the natural river. This might lead to decimation
impacts on of the fish population, especially if illegal fishing methods are being used
species such as use of explosives, poison and electricity. These methods are
migrating regularly used in other rivers in Nepal with dramatic effects. Information
upstream from local experts indicate that this illegal fishing is a widespread problem.
during During the monsoon season the flow will likely be sufficient for all species
monsoon to migrate upstream from the dewatered section.
Tributaries
Tributaries
◼ Negligible for The Chujung Khola HEP and Lower Barun Khola HEP are snow- and
Chujung Khola glacier fed cold and muddy rivers with low bio-production and if fish a small
HEP, Lower population.
Barun and
Upper Ikhuwa Khola HEP at high altitude is a “warm” river, but has a small
Upper Ikhuwa
fish population.
Khola HEP
Ikhuwa Khola HEP is a “cool-water” river, important as spawning area for
◼ High for IKHPP several fish species. This probably also represents the upper spawning
habitat for golden mahseer (IUCN-EN), and is important for the local and
regional population of snow trout and stone carp (endemic). Minimum flow
(10%) is not sufficient for migration, especially considering the wider
stream channel.
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Zone Likely cumulative Rationale
impacts of low flow
Cold-Cool Main Stem Lower Arun
800–400 The gradient in the Lower Arun River is less steep than further upstream,
◼ Negligible for
masl and it is a warm and productive river. A minimum flow (10%) might be
Lower Arun
HEP enough for several species migrating upstream during. No specific
evaluation available.
Tributaries
◼ High for Tributaries
Kasuwa Khola
Kasuwa Khola HEP is a warm river with a steep gradient and is potentially
HEP
productive for Tor putitora as well as several other fish species. Compared
◼ Negligible for to the assessment of Ikhuwa Khola, the 10% flow in this project will not be
Upper Ishuwa sufficient to serve the fish population. A landslide makes the river muddy,
HEP but that might be a temporary condition. Kashuwa Khola is the only river
along the upper part of the dewatered section that might provide vital
◼ Negligible for
biotopes for several fish species.
Isuwa Khola
HEP Isuwa Khola is a cold snow fed tributary, with Upper Ishuwa HEP and
Isuwa Khola HEP at high altitudes. The ecological value of this river is
◼ Moderate for
evaluated as low compared to the warmer tributaries in tis zone.
Apsuwa HEP
Apsuwa I HEP is located at high elevation, with steep gradient cold water
and if there are fish, probably a small population.
Upper Apsuwa HEP is located at high elevation, but the downstream
dewatered section might impede fish migration and affect fish fry
production, for both in-river and downstream (Arun River) fish populations.
With a 10% minimum monthly flow as EFlow, the impacts are assessed as
moderate.
Cool Main stem Lower Arun
From 400 Several tributaries add flow to the main stem, which will reduce the critical
◼ Moderate for
masl and impacts of a low EFlow. Sangkhuwa Khola is a major contributor with no
Lower Arun end
downwards planed hydropower projects. Fish migration in the Arun River may reach
its dewatered
Sangkhuwa Khola, which will provide these fish populations with spawning
section in this
and nursing habitats. If this connection can be sustained, the impacts of a
zone
10% minimum monthly flow could be reduced and still be a Moderate
Tributaries cumulative impact.
◼ High – 20
hydropower Tributaries
projects All tributaries are warm rivers with high bio productivity. Altogether, 20
planned in 7 hydropower projects are planned in 7 of the tributaries, which mean a total
tributaries massive hydropower regulation in the watershed. All projects will have a
dewatered section with varying gradients and river profiles. Compared to
the effects in the tributaries in the cold zone, this minimum flows will have
high impacts, both due to the reduction of bio-production in low flow
season and due to the low flow probably in several rivers, which will
impede fish migration and led to a dramatic reduction in the total fish
population in both Arun and Sun Koshi systems. High and dramatic
cumulative ecological effect.
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Peaking
Peaking projects provide daily or weekly regulation of flows by storing water in reservoirs behind the
dam. Water is passed through dam turbines to maximize power generation during times of peak energy
demand. As such, peaking projects can result in drastic changes to a river's flow – even on an hourly
basis. By releasing large quantities of flows within the span of a few hours, peaking projects create daily
fluctuations between flood and drought that can wash away or disrupt fish breeding grounds and aquatic
biota. Peaking projects could also result in rapid water level fluctuations and wetting and drying of banks
increases susceptibility to bank erosion and seepage erosion (piping) processes. Furthermore, peaking
projects increase shear stress during flow changes and thereby erosion and bed incision, causing
changes in bed habitat and water quality.
As a possible consequence of peaking it has been found that the biodiversity of macroinvertebrate
assemblages (measured with Shannon-Wiener diversity index) decreased at dams and downstream
locations from dams associated with hydropower plants in comparison to diversity in reference sites
(Armanini et al. 2014; Vaikasas et al. 2013). It was concluded that hydropower plants not only induce
cardinal changes in macroinvertebrate assemblage composition, but also in water quality in the riparian
ecosystem.
Peaking may also highly affect young and small fish living close to the shoreline. The effect is most
dramatic close to the tailrace outlet in the river, and the death rate due to stranding of fish depending
on how fast the water level drop after a peaking episode. Other important factors are the shoreline slope
and the substratum composition. How far downstream from the tailrace the peaking effect will be of
negative character depends on the operating procedures, the riverbed conditions and the added flow
from the tributaries, but the effects may occur some kilometers downstream. If the peaking operations
are heavy, it might also force large fish to leave the area with the unpleasant flow regulations. Daily
peaking may, if not operated in an environmentally adapted manner, lead to high mortality in the area
downstream from the tailrace outlet and result in depletion of the river ecosystem and a degraded
ecological condition. Upstream migrating fish might also be disturbed by these fast water level drops.
If all of the proposed mainstem hydropower projects are constructed, the effects of peaking on
downstream flows will be minor because the distance from each of the project’s powerhouses to the
next downstream reservoir is very short (often ~1 km or less). Peaking operations, and associated water
level fluctuations, can be significant in the interim for the Kimathanka, Upper Arun, Arun-3, and Lower
Arun projects, depending on the timing of construction of their next downstream project (Table 8.8).
Table 8.8: Likely Cumulative Impacts from Peaking in the Three Zones
Likely Cumulative
Zone Rationale
Impacts of Peaking
Cold Main stem Depending on the operating procedures and the riverbed
Significance variations conditions, there may be stranding effects in this vulnerable
depending on sequence cold environment. Fish fry are living close to the shoreline and
and timing of project will be easily impacted if the shoreline slopes are low. If the
construction, but shoreline is steep, the impacts will be less, but overall the
generally low in Upper cumulative impacts are considered Medium in this segment
Arun River, because of because of the number of dams and because nearly all of the
deeply incised river remaining riverine segments will be subject to at least seasonal
channel and low fish peaking operations.
abundance
Tributaries
Low – no peaking
projects planned
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Likely Cumulative
Zone Rationale
Impacts of Peaking
Cold-Cool Main stem The river section has high biodiversity and likely more than 20
Potentially High – due to fish species which are vulnerable to stranding. The effects
the Arun-3 PRoR depend on the operating procedures and the riverbed
Tributaries morphology. Without an environmentally adapted peaking
Negligible – no available procedure, the stranding and depletion effects might be
information about peaking substantial, hitting most of the species, such as the fry of Tor
projects putitora, snow trout, copper mahseer and all other fish species
that have fish fry living in this river section.
Cool Main stem Without an environmentally adapted peaking procedure, the
Potentially High – due to stranding and depletion effects might be substantial and will
the Lower Arun PRoR impact on the fry of Tor putitora, snow trout, copper mahseer
Tributaries and all other fish species that have fish fry living in this river
Negligible – no available section. The rivers in this area are wider with shallower shore
information about peaking lines and, thereby, have a higher probability for stranding
projects mortality.
Changes in Sediment Transport
The impacts of sediment flushing are most evident in low flow situations and in sections where the river
bed is dominated by rocks and boulders. In fine sand areas sediment flushing is not a problem. As the
main stem and tributaries in much of the three zones are dominated by stones and boulders impacts,
cumulative impact of sediment flushing can be considered to be High.
Climate Related Impacts
Climate change predictions for the Himalayan region of Nepal vary, but generally slightly warmer
temperatures are expected, which should result in slightly higher average river flows in the near to mid-
term as glaciers slowly melt, and then possibly slightly lower average river flows in the mid to long term
as glacier melt is reduced. It is difficult to definitively determine the effects of these changes on fish and
aquatic habitat. In the absence of project dams, slightly warmer air and water temperatures could extend
habitat suitability upstream along the Arun River for some species (e.g., golden mahseer), although
proposed dams will prevent golden mahseer and possibly other native fish species from accessing
potentially new suitable upstream habitat.
8.5.3 Summary of Cumulative Impacts
Table 8.9 provides a scheme for categorizing baseline ecological integrity (Kleynhans1996), which is
used to determine the significance of cumulative impacts on fish and aquatic habitat in the Arun River
Basin. From the cumulative assessment of impacts carried out above, the changes in ecological
integrity are predicted in the Arun Basin for each of the three zones and separately for the main stem
and tributaries (Table 8.10). The rationales for these changes are also provided.
As summarized in Table 8.10, the cumulative impacts of planned/under-construction HEPs, in
combination with climate change and other stressors, are predicted to result in a Largely Modified
ecological integrity in the main stems and tributary in each of the temperature zones – aside from the
cold zone main stem, which is predicted to be Moderately Modified.
Compared to the cool zone, the cold and cold-cool zones are expected to have more significant
cumulative impacts, as the baseline ecological integrity is less modified. As such, the following is a
summary of the cumulative impact significance to fish and aquatic habitat per zone:
◼ Cold Zone main stem and tributaries: High cumulative impact significance
◼ Cold-Cool Zone main stem and tributaries: High cumulative impact significance
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◼ Cool Zone Main stem and tributaries: Moderate cumulative impact significance
Table 8.9: Categories for Baseline Ecological Status
Ecological Description of Habitat Condition
Category
A Unmodified: Still in a natural condition.
B Slightly modified: A small change in natural habitats and biota has taken place, but ecosystem
functions are essentially unchanged.
C Moderately modified: Loss and change of natural habitat and biota has occurred, but the basic
ecosystem functions are still predominantly unchanged.
D Largely modified: A large loss of natural habitat, biota and basic ecosystem functions has
occurred.
E Seriously modified: The loss of natural habitat, biota and basic ecosystem functions is
extensive.
F Critically/extremely modified: The system has been critically modified with an almost complete
loss of natural habitat and biota. In the worst instances, basic ecosystem functions have been
changed and the changes are irreversible.
Source: After Kleynhans 1996
Table 8.10: Changes in Ecological Integrity for the Three Zones
Main Baseline Predicted
Temperature
Stem or Ecological Ecological Cumulative Impact Significance and Rationale
Zone
Tributary Integrity Integrity
Cold Main Unmodified Moderately High Significance
stem Modified No HEPs so far and anthropogenic pressures are low.
The HEPs in the main stem will have limited impact on
Tributary Unmodified Largely aquatic diversity, which is low due to cold conditions,
Modified but none of the proposed dams will have fish passage
facilities, representing a barrier to migration for key
species, like the common snow trout, and resulting in
fragmented and segmented fish populations. The four
proposed HEPs in this segment would convert the Arun
River to a series of dams, reservoirs, diversion reaches,
and segments subject to flow fluctuations from peaking
operations. HEPs on tributaries could have significant
impact depending on EFlow.
Cold-Cool Main Moderately Largely High Significance
stem Modified Modified Baseline aquatic diversity is high in this zone, although
modified by the presence of several settlements, some
sand and gravel mining and overfishing. The main stem
will be impacted by barrier effects on migratory fish, as
well as some peaking and sediment transport.
Tributary Moderately Largely High Significance
Modified Modified Baseline aquatic diversity is high in this zone, although
modified by the presence of several settlements, some
sand and gravel mining and overfishing. Tributaries will
be impacted by barrier effects on migratory fish and
sediment transport.
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Main Baseline Predicted
Temperature
Stem or Ecological Ecological Cumulative Impact Significance and Rationale
Zone
Tributary Integrity Integrity
Cool Main Largely Largely Moderate Significance
stem Modified Modified Baseline conditions have been modified by over-fishing
and use of destructive techniques for fishing, as well as
some sand and gravel mining. However, given the
absence of peaking projects and the dominance of run
habitats, unlikely to be impacted by low flows, there is
unlikely to be a major changes in ecological integrity.
Tributary Largely Largely Moderate Significance
Modified Modified Baseline conditions have been modified by over-fishing
and use of destructive techniques for fishing, as well as
some sand and gravel mining. Due to barrier effects on
fish species as well as the impacts of low flows and
sediment flushing, ecological integrity will further
deteriorate.
8.6 Cumulative Impact on VEC: River-based Livelihoods
8.6.1 Key Stressors and Impacts
Shown in Table 8.11 are the primary stressors and impacts on river-based livelihoods from planned
hydropower projects, road developments, and climate change in the Arun River Basin.
Table 8.11: Stressors and Cumulative Impacts on Livelihoods
Stressors Potential Cumulative Impacts on Livelihoods
◼ Hydropower developments ◼ Effects on irrigation
◼ Electricity development ◼ Effects on rafting outfitters
◼ Road development ◼ Effects on artisanal fishing
◼ Climate change and natural hazards ◼ Effects on river mining
8.6.2 Cumulative Impacts
It is expected that there will be improved quality of life for people living in settlements to which the
generated electricity will be distributed. However, improved living conditions in these settlements will
likely lead to population increases, which will in turn lead to social cohesion impacts (Section 8.8) and
increased pressure on the ecosystem services of the surrounding areas, as people will look to gather
resources from CFUGs and surrounding forest areas.
Considering a high-level baseline vulnerability, the cumulative impacts from hydropower, road and
transmission line developments will be even more significant for vulnerable groups (e.g., women, Dalits
and indigenous people). This is particularly the case for those whose livelihoods depend on river
resources, perform spiritual rituals in the rivers, or live near hydropower, road, and electricity
development projects.
Irrigation
Agriculture is the sector that contributes the most to Nepal’s GDP; however, raising productivity through
irrigation is constrained by the lack of electricity (Bharati 2019). The national grid has not reached all
rural areas, and where it has reached, farmers have not always been able to access the subsidized
farm power connection. Where farm power is available, the electricity supply is often intermittent and
unreliable (Neupane 2019).
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In the hills and mountains, the main restrictions on water access are geophysical, with water mostly
accessible in the valleys below the steep slopes, with rocky subsoil limiting the possibility of storage.
Thus, rain fed agriculture is still the method of choice in most of this area (Neupane 2019).
Hydropower Projects
Well-planned multipurpose hydropower projects have the potential to provide co-benefits such as
irrigation to support local livelihoods and improve food security. For example, the Sapta Koshi Project
would create a large reservoir at Chattara in Nepal which would supply year-round irrigation in the
downstream areas. The proposed dam could irrigate more than 1.5 million ha – 546,000 ha in Nepal
(Mahattari, Chanusha, Siraha, Saptari, Sunsari, Morang, and Jhapa) and 1,053,000 ha in Bihar, State
India. However, the Sapta Koshi Project would inundate 3,764 ha of agricultural land within 15 local
levels in Sankhuwasabha, Dhankhuta, and Bhojpur districts. River valley farming systems (which are
considered to be of high production capacity) would be most affected by this inundation. As there are
limited agricultural land in the hills and mountains, inundation of large amounts of agricultural land may
cause severe impacts on production (Rai and Linkha 2020).
Peaking projects provide daily or weekly regulation of flows by storing water in reservoirs behind the
dam. As such, peaking projects can result in drastic changes to a river's flow – even on an hourly basis
– which can impact on the availability of irrigation. This is more of an issue in the middle and lower Arun
River Basin where slopes are gentler and land suitable for agriculture use are found along the river.
Reduced flows in the diversion reaches of the HEPs may result in significant livelihood impacts on those
who rely on the affected stretch for irrigation and fishing. Such impacts have been reported in the
diversion reaches of other recently commenced HEPs in eastern Nepal.
Road Developments
Communities in Khandbari Urban Municipality have witnessed road construction activities destroy
irrigation tunnels. As a result, the community has demanded additional budget for the repair and
maintenance of the affected irrigation tunnels.
Climate Change
Climate change is likely to have a great impact on agricultural water security in the future. Pre-monsoon
precipitation is projected to decrease and extreme precipitation events to increase (Neupane 2019).
There is also a high likelihood of stronger monsoons in the future, which will increase impacts and the
risk of related disasters such as landslides and floods (Bharati 2019). Moreover, increasing erosion,
landslides, and sediment will complicate repair and maintenance, making it more costly and reducing
the command area for surface irrigation.
Summary of Impacts on Irrigation
In summary, considering the predominant reliance on rain-fed irrigation, the impacts on irrigation are
considered to be of Moderate Significance to communities upstream from the Lower Arun HEP
powerhouse. If the Sapta Koshi Project is built, as planned, the impact on irrigation and agriculture is
considered to be of High Significance, due to the large areas of agricultural lands that would be
inundated.
Artisanal Fishing
Fishing is a supplementary source of livelihood for people in the basin, complementing other existing
income and nutrition sources. Fish is also considered an important part of various cultures, rituals, and
traditions. For example, in Rai community, fish is an important food item for Kul Puja, which is celebrated
every year. Whereas among the Majhis, it is used during death rituals.
Sabha Khola (which meets the Arun River approximately 10 km downstream from Khandbari) is the
most popular fishing area in the basin. Fish from Sabha are considered to be of higher quality and fetch
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a higher price at market, up to NPR 1,200/kg. Fishing activities on the Sabha contribute to subsistence
livelihoods in some communities.
Accounts from consultations suggest decreases in fish catch over the last decade resulting in a decline
in artisanal fishing as a livelihood (capture fishing, small-scale commercial fishing, subsistence fishing,
and recreational fishing). The plummeting number of fish is primarily owing to a general increase in
resource dependence, haphazard infrastructure development (e.g., dumping of road debris into the river
during road construction), an increase in electrofishing, increased incidents of floods and landslides,
river mining, and lack of regulation, among other things. Sabha is steeper than the Arun River and has
seen more flooding incidents in the last decade, which has impacted upon the fish population in the
river. This has resulted in communities shifting to other forms of livelihood, such as construction work,
daily wage labour, and small businesses. However, some communities are more dependent on fishing
than others. For example, approximately 50% of Kumal households near Tumlingtar and 75% of
households in Barhabise (Sabha Pokhari Rural Municipality) are dependent on fishing for at least 6
months in a year and may bear higher livelihood impacts.
Any additional infrastructure development, therefore, is likely to add stress to the existing impacts. In
addition, road construction and the disposal of road debris in the river (e.g., access roads) may increase
the incidence of landslides resulting in impact on fish populations. HEPs will result in barrier effects and
changes in hydraulic and hydrological regimes as discussed in Section 8.6.
Reduced flows in the diversion reaches of the HEPs may result in significant livelihood impacts on those
who rely on the affected stretch of river for fishing. Hydropower structures may also block the migration
of important fish species which could severely impact Kumul and Barhabise communities, and other
households that rely on fishing as a primary source of livelihood.
In summary, given that fishing is not a major source of income, and as most of the fishing activities are
on the Sabha Khola or lower Arun River, cumulative impacts on small scale commercial fishing is
considered to be of overall Negligible Significance for the basin and of High Significance for fishing
livelihoods on the Sabha Khola.
River Mining
The local government restricts commercial river mining in the Arun River. However, households use
raw materials from Arun River for household purposes (e.g., construction of houses). River mining is
most popular in the Sabha River, where it contributes approximately NPR 2.2 million to the Khandbari
Municipality and is used to build local infrastructure such as hydropower projects and roads.
River mining is a regular source of income for communities around the crusher plant at Sabha Khola,
which is located 12 km downstream from the Lower Arun Powerhouse. On a given day, groups of 5–7
people make 35 trips of gravel, sand, and stone collection from the riverbank. Sedimentation flushing
from upstream hydropower projects is not likely to have an impact on these crusher plants. However, if
the downstream Sapta Koshi Project was to be built as currently proposed, sand dunes along the
riverbank will be inundated, which would impact on the livelihoods of river miners and affect local
government revenue. The Sapta Koshi Project would likely impact downstream river mining, because
its large reservoir is likely to trap much sediment.
Agricultural activity and road development will potentially increase erosion and, subsequently, the
sediment transport in various reaches of the basin, but the coarser grain sizes will still be trapped within
the various impoundments. It should also be noted that, if practiced unsustainably, sand and gravel
extraction could increase riverbank erosion and result in negative hydrological and biodiversity impacts.
In the absence of the Sapta Koshi Project, cumulative impacts on river mining-based livelihoods are
considered to be of Negligible Significance, because of the upstream flushing of sediments, which
should maintain a quasi-natural sediment transport. If the Sapta Koshi Project were to be built, the
cumulative impacts on river mining-based livelihoods would considered to be of High Significance, as
much of the sand deposits along the Sabha River would be inundated.
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Rafting Outfitters
The lower Arun River is used for recreational boating by several rafting outfitters. Although the exact
rafting put in and take out points vary by outfitter, most generally put in just upstream from Tumlingtar
and take out just downstream from the confluence with the Sapta Koshi River (Figure 8.9). Moreover,
the opening of the Koshi Highway (including the Num-Kimathanka Road) and access roads will improve
accessibility to previously isolated locations – which could benefit rafting outfitters and tourism activities
In the basin.
The put in location for rafting is downstream from the Lower Arun HEP tailwaters, so would not be
affected by any of the upstream hydropower facilities. The Lower Arun HEP, however, is a PRoR
operation, which would control flows for most of the rafting river segment. Depending on the timing of
the Lower Arun HEP peaking, the PRoR operation could have either a beneficial or adverse impact on
rafting. If peaking occurs during morning or early afternoon hours, the peaking flow of 253 m 3/s would
likely provide reliable high-quality flow, which would support rafting. If the peaking occurs during late
afternoon or evening, then the outfitters and their customers would likely only have the project’s
proposed EFlow (i.e., 10% of the average monthly flow) plus any tributary inflow, which would likely be
insufficient to provide a quality recreational experience.
If the Sapta Koshi High Dam Project was to be built as currently proposed, it would flood the entire
section of the Arun River used for rafting and the current rafting take out point would be downstream
from the Sapta Koshi Dam. This project would eliminate the appeal of the lower Arun River for rafting,
although it could potentially create other water-based recreational opportunities within the reservoir.
Moreover, the opening of the Koshi Highway (including the Num-Kimathanka Road) and access roads
will improve accessibility to previously isolated locations, which could benefit rafting outfitters and
tourism activities in the basin. In summary, the cumulative impacts on rafting outfitters in the Upper Arun
River would be considered of Low Significance as very little rafting is occurring, but the effects of the
Sapta Koshi and, to a much lesser extent, the Lower Arun HEP would be considered of Moderate
Significance, as they would have a significant impact, but on a relatively low number of outfitters.
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Figure 8.9 Arun River Rafting Map
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8.7 Cumulative Impacts on VEC: Settlement
8.7.1 Key Stressors and Impacts
Shown in Table 8.12 are the primary stressors and impacts on settlements in the Arun River Basin.
Table 8.12: Settlement Stressors and Impacts
Stressor Potential Impact on Settlement
◼ Hydropower development ◼ Change in settlement demographics
◼ Electricity development ◼ Improved public infrastructure
◼ Road development ◼ Change in livelihood sources and income generation
◼ Climate change and natural ◼ Governance impacts
hazards ◼ Potential increase in trafficking in persons and gender based
violence
8.7.2 Cumulative Impact
Overall, in the short term (1–5 years), it is anticipated that improved roads will increase opportunities
for people to bring their agricultural products to market and improve access to healthcare and education
facilities. Hydropower construction will result in an influx of labour, which will likely generate more local
business, particularly at tea stalls and eateries, with a possible shift from traditional sources of
livelihood. However, this can also result in increased gender-based violence near these establishments
and other significant impacts in less densely populated areas (Section 8.8). An Increase in
infrastructure development in the area may also increase the responsibilities for the local government
including an increase in monitoring and security requirements for individual projects, and an increase
in security needs for communities to manage increased influx.
There is a potential that, in the medium term (5–10 years), improved transport and electricity
infrastructure may result in increased migration into the basin. This could further increase the pressure
on agricultural lands and non-timber forest products.
Change in Settlement Demographics/Patterns
A change in settlement demographics is likely to be one of the major impacts of infrastructure
development in the region. Given that villages in the region are a cluster of a limited number of
households, increased access and influx may result in a change in settlement demographics. For
example, Namase, Rukma, and Chepuwa are primarily Bhote communities with a distinct culture and
language, and a change in settlement patterns will potentially have additional impacts on cultural
identity. In addition, climate change impacts may have additional impacts on settlements, with accounts
of landslides, floods, and the drying up of springs posing a threat of relocation.
Overall, the cumulative impacts on change in settlement demographics to previously remote villages is
considered to be of High Significance. Descriptions of the impacts on settlement demographics from
hydropower projects, improved road connectivity and climate change are discussed below.
Public Infrastructure
Infrastructure development in the region is expected to result in improved public infrastructure as
discussed below.
Road Connectivity
Road connectivity is a recent phenomenon in the region. The Tumlingtar-Khandbari road was built in
2010, the Khandbari–Num road was completed in 2016, and the track beyond Num was recently
opened in 2018 as a part of the Koshi Highway and is in the process of being completed. While the road
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from Tumlingtar to Khandbari is black topped, the one from Khandbari to Num is currently being
upgraded, and the one beyond Num is only a track opening and is non-operational during the monsoon
season. As a result, communities closer to this highway are already seeing changes in demographics,
as well traditional sources of livelihood.
Through the CIA consultations with downstream communities, the benefits and negative impacts of
road construction were widely recognized. The consultees shared that road construction enables
farmers to transport their agricultural products to markets and promote local economic activities;
however, they also explained that the construction of roads has destroyed farmlands, forests/community
forests, and water sources (e.g., due to associated landslides and dumping of soil into the river).
Access to Healthcare
Communities will have better access to healthcare facilities, with an increase in road connectivity. As
an example, the road opening to Gola has reduced travel time for local residents from a day’s walk to
few hours of ride to Num, where there is a better health facility.
Electrification
An increase in hydropower development in the region will also result in reliable access to electricity in
the region. While some areas are connected to the national grid, the majority of the villages are reliant
on micro/mini hydro schemes or solar energy, which is not often reliable. Increased access to electricity
may also result in productive end use of electricity, including an increase in small businesses reliant on
electricity source.
Livelihood Sources and Income Generation
The Koshi Highway development is changing the face of traditional agriculture in the region; subsistence
farming is being replaced by commercial farming, and the effect is seen greater along the roadsides.
Although road developments impact on traditional livelihoods and social cohesion ( Section 8.8), the
increased connectivity often results in improved economic activities. Pande (2017) observed a 21%
reduction in poverty in Ramechhap, Rasuwa, and Taplejung districts after introduction of access roads
through projects funded by the Asian Development Bank (ADB). The observed poverty reduction was
in part a result of increased access to markets, which reduced travel time from farm to market and
improved agricultural productivity.
Moreover, studies show that a lack of proper transport facilities and road linkages results in a
considerable proportion of wasted agriculture products in rural Nepal. These studies indicate that
Nepalese farmers lose about 25–30% of their product before reaching the market.
The recent urbanization of Num has also seen an increase in hotels and small businesses, a major shift
from agriculture.
The migration of some men to urban centers and abroad has increased the number of women engaged
in agriculture, as well as contributed to an increase in female-head households. However, women are
less likely to have land registered in their name or obtain documentation to prove entitlement, which
further magnifies the impact of land acquisition for the development of hydropower, roads, and
transmission lines.
Governance Impacts
Increases in infrastructure development may add stress to the existing human resources available
within the local and district government, as they bear the responsibility for monitoring, as well as
facilitating coordination between the project and the communities. There may be an increase in demand
for security personnel, in addition to clearances that may be required for various purposes, e.g., the
divisional forest office will be responsible for any clearances required for community forests.
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Trafficking In Persons/Gender Based Violence
The underlying causes of trafficking include poverty, limited socio-economic opportunities, and the lack
of sustainable livelihoods. Women and girls are especially vulnerable due to gender discrimination,
illiteracy or low education, and low socioeconomic status. In Nepal, those most targeted tend to be from
traditionally excluded and socially marginalized groups, such as members of formerly ‘enslavable’
aadibasi/janajati ethnic groups, as understood from consultations with the local community.25
It is understood that personal aspirations play a major part when offenders are not from the known
social circle of the victims. Juvenile and adolescent victims especially fall prey to the false promises
made by strangers not only for an economically stable life, but also for exposure to different
geographies, cultures, traditions, and what they believe would be a better way of life. In rural areas,
Internet connectivity and smart phones have brought greater exposure, leading to new aspirations
among the youth, some of whom choose to leave home. The aspiration for a better life leads some
people to be trafficked, as they place their trust in unknown persons who turn out to be traffickers.
Given this context, the influx of labor and other development activities related to the project may
contribute to an increase in the risk of trafficking in persons, especially during project construction,
which warrants appropriate mitigation measures to address such risks.
8.8 Cumulative Impacts on VEC: Social Cohesion
8.8.1 Key Stressors and Impacts
Shown in Table 8.13 are the primary stressors and impacts on social cohesion from planned
hydropower projects, road developments, and climate change and natural hazards in the Arun River
Basin.
Table 8.13: Social Cohesion Stressors and Impacts
Stressor Potential Impact on Social Cohesion
◼ Hydropower developments ◼ Impacts on social capital
◼ Electricity development ◼ Impacts on sense of place
◼ Road development ◼ Impacts on cultural Identity
◼ Climate change and natural ◼ Impacts on social inclusion
hazards
8.8.2 Cumulative Impact
Communities and individuals near hydropower and road developments in the basin may experience
diminished social cohesion and cultural identity due to direct and induced impacts, including land
acquisition and resettlement, workforce mobilization, and population influx.
Resettlement has the potential to disturb currently cohesive communities – both those that are resettled,
and those that act as hosts to relocated populations. Social cohesion, or the quality of a group
collaboration or unity, may be disturbed, as communities (particularly aadibasi/janajati groups), which
observe unique norms, mores, and languages, are combined, as the partial resettlement of formerly
whole communities potentially takes place, and as local power dynamics and structures are disturbed.
Additionally, through the process of resettlement, relocated people will be separated, either temporarily
or permanently, from spaces that hold community and cultural significance, including cemeteries,
gathering spaces and ancestral lands. These separations can diminish social cohesiveness, as well as
connection to cultural identity.
25
KII with Shakti Samuha at Sindhupalchowk, Chautara 5
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The mobilization of the hydropower project workforce, as well as HEP induced influx or in-migration,
will create demographic changes that may further diminish social cohesion and cultural identity. For
instance, during the construction of the UAHEP, a peak workforce estimated at 4,500, with about 60%
likely to be foreign nationals, will enter the Project area. The presence of foreign nationals and other
‘outsiders’ in local communities with unique cultural norms, mores , and languages, may disrupt the
cohesiveness of existing communities located near work camps, and in communities where workers
spend leisure time and make organized trips to purchase personal items.
The on-going construction of the Koshi Highway and access roads to be built for hydropower projects
will greatly benefit the communities by connecting them to basic services such as healthcare, and
education, among other things. However, it will also increase intra-district mobility of various ethnic
groups, haphazard urbanization, and, if unmanaged, may disrupt the social cohesion, cultural norms,
and the identify of communities.
The cumulative impact on social cohesion is, therefore, considered to be of Moderate Significance for
the lower Arun Basin (from Tumlingtar to Num/Dovan at the Arun-3 headworks location) and High
Significance for the upper region from Arun-3 headworks site to Kimathanka.
Social Capital
Local power dynamics and structures may be disturbed through resettlement activities, both for
resettled communities that are absorbed by new host communities, and for host communities which
incorporate new populations. This disturbance may lead to a reduced or lost access to local power
structures and social capital for some members of these communities. As discussed earlier, there is a
high interdependence among communities in the area. The Kiduk Samaj, which plays a central role in
decision-making on village matters mostly, related to birth and death rituals, is prevalent in the UAHEP
area. Such local structures may be potentially impacted by demographic changes resulting from
displacement, influx and urbanization.
With changes in community membership resulting from resettlement activities, or the dilution of a
community with new entrants through project induced influx, existing social safety nets may be
weakened or lost. Social safety nets include informal, but established, patterns of caring for elders,
impoverished, or otherwise socioeconomically vulnerable individuals who may not have the means to
meet their basic needs independent of community support. This is more significant among indigenous
communities, which are more communal. Communities reported relying on neighbors during health
emergencies, or for financial advice, among other things. Vulnerable households without land
ownership often rely on someone else’s land for their livelihood (land users). Losing land access will
potentially result in increased vulnerability for such households.
This impact is likely to be more significant in the upper region with no current road connectivity, higher
level of community dependency, and the presence of local structures such as Kiduk Samaj, than the
lower region, which has already seen some of these changes with the development of the Koshi
Highway as well as Arun-3 HEP. Hence, the cumulative impact on access to lower power structures
and social capital is considered to be of High Significance in the upper region of the Arun River Basin
and Moderate Significance in middle and lower regions of the basin.
Sense of Place
The concept of “sense of place” is interactional and psychological, which makes it very difficult to move
away from a place that one consider home. Infrastructure development often impacts on a multitude of
place related values, including land, traditional forms of livelihood, access to natural resources, such as
resources from community forests, access and use of rivers, cultural heritage resources, and social
capital, among other things, which will be potentially impacted by the UAHEP as well all other
infrastructure development in the Arun Basin. Such impacts are likely to be more significant among
indigenous communities with a high dependency on natural resources. Furthermore, impacts are likely
to be higher for the elderly population, than for younger people.
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Land acquisition resulting in physical displacement is one of the most critical impacts on communities’
sense of place. In addition, given the limited availability of replacement land in the area, the likelihood
of having to move to a different community is higher, which adds to the impact.
Accounts from communities suggest that they have a spiritual connection to their land, as well as their
surroundings. As an example, communities in Namase reported that they feel protected by the hills
around them that they revere as God, while those in Limbutar shared their connection with trees that
they grew up with.
Irrespective of road connectivity, there will be significant impacts on sense of place in the lower region
as well as the higher region of the Arun Basin from infrastructure development and the UAHEP,
respectively. As such, the cumulative impacts on sense of place are considered High Significance.
Changed Cultural Identity
Demographic changes in local communities generated by resettlement activities and hydropower and
road development induced influx, including workforce, workforce families, and other economic
opportunity seekers, will contribute to impacts on cultural identity. The influx of non-nationals will impact
on the cultural fabric of the local communities in the places where they work, reside, or spend leisure
time, diluting local norms and language. In addition, homogenous communities such as the Bhote
community in Namase may see an increase in population from other communities of different ethnic
backgrounds, influencing the intangible cultural resources, such as languages, festivals, and Bhote
scripts.
Traditional artefacts may see a decline resulting from a change in livelihood patterns and increased
connectivity to markets. Communities in this region have a spiritual connection to the river and perform
several rituals around the riverbanks, including Kul Puja and cremations. A decrease in EFlow with the
several hydropower projects that are planned and under construction may have severe impacts on
access to the river for cultural purposes.
Haphazard development resulting from road connectivity and population influx may impact on the
traditional architecture of the place. This is evident from new non-traditional structures in Num and
Khandbari.
This impact is likely to be more severe in the upper region with no current road connectivity, than the
lower region, which has already seen some of these changes with the development of the Koshi
Highway as well as Arun-3 HEP. Hence, the cumulative impact on cultural identify is considered to be
of High Significance in the upper region of the Arun River Basin and Moderate Significance in the
middle and lower regions of the basin.
Generation of Social Tension (including TIP and GBV)
Social tensions may be produced by a variety of project activities and induced impacts, which may
create a number of unique schisms and affect a range of communities and individuals. With the entrance
of project induced influx, competing cultural norms, mores, language, and customs, and pressure on
limited social and environmental resources and public services, social tensions can arise between
receiving communities and new entrants. These tensions can be enhanced, particularly when due to
the size or economic power of the incoming population, local communities experience or perceive
themselves as experiencing economic or cultural marginalization, or when the impacts of increased
crime and delinquency arise with the influx.
In situations where there is not widespread public consent to development, social tensions may arise
between project opponents and proponents. These divisions may occur along the lines of stakeholders
or community members who perceive themselves to be beneficiaries of project development
(employment opportunities, supply opportunities, or other economic benefits or compensation for losses
that are considered fair and advantageous), and those who do not. Differences in lifestyle and levels of
development present within the project area may increase as certain members of communities secure
work or supply opportunities with the project, while others do not; this can also contributing to tension
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and intra-community divisions. These divisions also can occur between generations, ultimately leading
to a deterioration of social cohesion within communities.
Incidents of potential trafficking and sexual violence may increase with population influx, as often
reported in other infrastructure development, if not carefully monitored. These impacts are likely to be
more significant in the upper region, with the concentration of laborers and other small businesses,
which has already seen some of these changes with the development of the Koshi Highway as well as
Arun-3 HEP. In summary, the cumulative impact from the generation of social tension is considered to
be of High Significance.
8.9 Summary of Cumulative Impacts on Selected VECs
Overall, a full development scenario (with over 30 hydropower projects) in the Arun River Basin will
have significant adverse cumulative impacts on the river and communities. These impacts would be
further exacerbated by road and transmission line development, climate change, and natural hazards.
And these impacts will be even more significant for vulnerable groups. A summary of the cumulative
impact significance for each selected VEC is shown in Table 8.14.
Table 8.14: Summary of Cumulative Impact Significance for each VEC
VEC Metric Cumulative Impact Significance
Natural forest integrity Forest loss and fragmentation Upper Arun River Basin: High
Middle Arun River Basin: Moderate
Lower Arun River Basin: High
Makalu Barun National Park Forest loss and fragmentation MBNP: High
Water resources River flow High
River water quality Moderate
Geomorphology Moderate
Sediment transport Upper Arun River: Moderate
Lower Arun River - High
Fish and aquatic habitat Changes in ecological integrity Cold Zone: High
Cold-Cool Zone: High
Cool Zone: Moderate
River-based livelihoods Impacts on irrigation Upper Arun River Basin: Negligible
Lower Arun River Basin: High
Impacts on artisanal fishing Overall basin: Negligible
Sabha Khola: High
Impacts on rafting outfitters If Sapta Koshi Project is built: Moderate
Settlement Changes in settlement Upper Arun River Basin: High
demographics patterns
Social cohesion Impacts on sense of place Upper Arun River Basin: High
Deterioration or loss of social Upper Arun River Basin: High
safety nets Mid/lower Arun River Basin: Moderate
Access to local power Upper Arun River Basin: High
structures / social capital
Mid/lower Arun River Basin: Moderate
Generation of social tension Upper Arun River Basin: High
Mid/lower Arun Basin: Moderate
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9. PROPOSED CUMULATIVE IMPACT MANAGEMENT STRATEGY
9.1 Overview
Effective application of the mitigation hierarchy (avoid, reduce, mitigate, and compensate) to manage
individual contributions to cumulative impacts is recommended as best practice. The UAHEP and other
sponsors of other hydropower projects in the basin should incorporate project design features that
include physical and procedural controls to avoid and reduce possible impacts, that are planned as part
of the projects.
The responsibility for the management of cumulative impacts ought to be collective, requiring individual
actions to eliminate or minimize each individual development’s contributions. Project sponsors should
be responsible for mitigating their own contribution to cumulative impacts, as well as participating in
collaborative watershed management efforts. Moreover, management measures recommended during
the CIA process may ultimately be effective only if the Nepal government becomes actively involved
(IFC 2013).
The project sponsors should foster collaboration by participating, to the extent feasible and practicable,
in working groups and/or government initiatives. The collaboration should be aimed at addressing the
management of potential impacts on regional resources to which the projects could incrementally
contribute with respect to cumulative impacts. An example of a collaborative cumulative impact
management strategy, as recommended in the Upper Trishuli-1 Hydropower Project CIA, is shown in
Box 9.1.
Box 9.1: High Management Approach
The Upper Trishuli-1 Hydropower Project CIA study identifies VEC-specific potential cumulative impacts in the
Trishuli River Basin, and proposed mitigation and monitoring measures at three different stakeholder levels:
individual hydropower developers; government authorities; and local communities. Additional management actions
at a higher level, such as a High Management Approach, are also suggested to address the significant cumulative
impacts that are predicted to affect the Trishuli River Basin.
The High Management Approach involves a combination of quasi-regulatory, incentive-based, and technical
measures, in this example aimed at: managing fish populations; regulating sediment mining; and applying general
watershed management measures. Together, these measures contribute to the improvement of habitats and
consequently reduce cumulative impacts on the identified VECs. This High Management Approach suggests
measures to be cooperatively implemented by hydropower developers, governmental authorities, and local
communities.
Source: ERM 2019. Upper Trishuli-1 Hydropower Project Updated Non-Technical ESIA Addenda.
9.2 Possible Mitigation and Management Measures
Shown in Table 9.1 are possible mitigation and management measures to avoid/minimize/restore
potential cumulative impacts on the selected VECs.
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Table 9.1: Possible Mitigation and Management Measures
VEC Possible Mitigation and Management Measures
Government-led Measures Project Sponsor-led Measures
Water ◼ Nepal’s default guideline for EFlows, which ◼ Attention should be given to
resources requires EFlows to be 10% of the minimum management of EFlows in cascades
average monthly flow unless the EIA where there should be consistency in
recommends a higher flow, should be re- operating rules for the powerhouses,
evaluated to include the evaluation and and operation of power plants should
management of the impacts of flow be coordinated to maintain EFlows in
modifications on biodiversity. IFC Guidelines the cascade.
on the selection of EFlow methods could be
adopted as a model (IFC 2018a). The EFlow
required to maintain aquatic integrity in the
Arun River Basin is strongly linked to the
river cross-section and geomorphology, with
narrow incised river channels requiring less
EFlow to maintain aquatic integrity while
broader river channels require more EFlow.
◼ Further research is needed on the habitat
requirements of fish and other aquatic
species in relation to river flow rate, water
depth, and so forth, in order to provide the
data needed for EFlows assessments and an
underlying rationale for the selection of
EFlows.
◼ Compliance monitoring should be increased
to ensure that EFlows, as approved in the
EIA, are actually provided.
Natural ◼ Develop a transmission master plan for the ◼ Develop a Workers’ Code of Conduct
forest Arun and neighboring river basins so as to specifying prohibited activities (such
integrity optimize/share transmission lines among as killing of wildlife and consuming
hydropower projects. game meat, setting fires) and enforce
◼ Improve forest restoration achieved through punishments when the code is
appropriate research into the propagation of violated.
broader range of locally indigenous tree ◼ Avoid development of access roads
species, improve available horticultural for hydropower projects through
facilities, provide training for horticulturalists, KBAs and protected areas to the
support the restoration of faunal species that extent possible.
play an important role in forest ecosystems ◼ If there are no alternatives, use
(e.g., monkeys for seed dispersal), facilitate commonly constructed access roads
research by universities into wholistic forest on a shared basis between
ecosystem functioning and management, hydropower projects.
equipping, and provide training for forestry ◼ For transmission lines, use bird
staff, support allocation of forestry and other diverters spaced across conductors
budgets for restoration activities, collaborate in an appropriate manner to enhance
with and learn lessons from the UN Decade visibility and with the ability to glow at
of Ecosystem Restoration initiative, etc. night for nocturnal migrants;
◼ Establish a reporting scheme in
coordination with the local
environment agency and forestry
authority.
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VEC Possible Mitigation and Management Measures
Government-led Measures Project Sponsor-led Measures
◼ Coordinate closely with qualified
partners, e.g., NGOs/government
working group on forest and
watershed conservation.
MBNP
◼ A mechanism needs to be developed at the ◼ Support the management initiatives
level of the Nepal Ministry of Finance to of the MBNP conservation authorities
retain funds generated from hydropower to and Community Conservation
be allocated for MBNP management Programmes, so that they are better
purposes. able to cope with the increased
pressure from influx and other
◼ Support to the MBNP should be considered
impacts. Support should be towards
by the large financial institutions such as
improved park facilities (e.g., offices,
World Bank, Global Environment Facility
communications, vehicles, and
(GEF), etc.
maintenance capacity), infrastructure
to access areas for easier
management, boundary demarcation,
staff training and equipment, and
revision of management plans,
among other things.
Livelihoods ◼ Implement a monitoring and evaluation ◼ Identify the exact number of
scheme to track agriculture land and land households affected by the loss of
use conversion and assess livelihood community forests acquired by the
activities related to fishing and those that project. Consult affected
depend on terrestrial biodiversity and forest communities to discuss ways in
land (e.g., hunting, forest product extraction). which their loss of access to
◼ Implement monitoring and evaluating to community forests can be
understand changes/impacts (if any) on compensated.
livelihood activities that depend on water ◼ Carry out agricultural intensification
resources quality and quantity (such as schemes to make upland land more
agriculture, livestock rearing and domestic productive (through irrigation) so that
use). the impact on overall productivity in
the basin is mitigated;
◼ Consider women’s crucial role in the
management of agriculture and forest
resources. The distinct impacts of
land (and forest) acquisition on
women should be documented and
addressed properly to make sure
women’s status does not deteriorate
further.
◼ Establish a reporting scheme
commitment in coordination with the
local forestry and agriculture
agencies.
◼ Adopt sustainable fishing techniques
under programs that have already
seen success in Nepal, such as One
Village One Pond.
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VEC Possible Mitigation and Management Measures
Government-led Measures Project Sponsor-led Measures
◼ Cold-water aquaculture schemes
focused on specific communities,
such as the Majhi and the Magar.
◼ Establish a reporting scheme
commitment in coordination with the
local water resource agency.
◼ Coordinate closely to implement
interventions, if necessary with a
qualified NGO/government working
group related to water resource
management and irrigation.
Settlement ◼ Raise awareness among local communities ◼ Respect and fulfil human rights
and social and other stakeholder groups (including obligations enshrined in ILO
cohesion hydropower developers and sand and gravel Convention 169 and UNDRIP for
mining entities) upstream for the proper protecting the rights of indigenous
management of waste along with specific peoples.
zones being declared for muck/spoil disposal ◼ Follow due process of FPIC.
etc. – including excess borrow and inert ◼ Ensure meaningful participation of
waste. project-affected indigenous and local
communities in all phases of the
project – planning, implementing,
monitoring and evaluation.
◼ Provide required information on the
project to the affected communities.
◼ Ensure both quantity and quality with
respect to the representation of
women in project-related
consultations and decision-making
processes. Women’s concerns
should be clearly reflected in the
mitigation plans/measures.
◼ Develop a Workers’ Code of Conduct
for proper waste management –
which specifies which activities are
allowed (and which areas can be
used for muck/spoil disposal etc.)
and impose penalties if the conduct
is breached.
Fish and ◼ Research is needed to understand fish ◼ Successful fish passage systems in
aquatic behavior for upstream and downstream the Himalayas should be used as
species migrations across dams, to support design of examples of fish passage design and
fish passage systems that are effective, operation for the fish species of
especially for the Sapta Koshi and Lower interest in the basin, namely snow
Arun HEPs, which will impact upstream trout and golden mahseer.
migration of several species, including the ◼ Fish ladders are not possible on all
endangered golden mahseer. dams, especially high dams, so other
◼ Guidelines should be prepared for the design fish passage techniques should be
of fish passes specifically suited for considered beyond the provision of
indigenous species (IFC 2018b). Continuous fish hatcheries (see discussion
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VEC Possible Mitigation and Management Measures
Government-led Measures Project Sponsor-led Measures
research, guided by monitoring, is needed to below). Alternatives include trap and
improve the design of passages and to trucking fish around the dams,
identify technologies that are suited for nature-like fishway, and habitat
particular conditions. enhancements to help maintain fish
◼ Development of a robust methodology for populations between dams. All low
monitoring the effectiveness of fish passages dams on rivers/streams with
(e.g. counting the number of fish that pass migrating fish should include a
through the ladder) is needed for all HEPs functioning fish passage facility.
with a fish passage. ◼ Downstream fish passage facilities
◼ Capacity building is needed for hydropower should also be provided to maintain
project environmental staff, as well as for fish populations.
government employees who work with fish ◼ Environmental Flows (EFlows)
passages, in order to ensure that they are should be designed within the
able to monitor and assess the efficacy of framework of sustainable
the passages. development to balance the
◼ There is a need for strengthened monitoring conservation of aquatic ecosystems
and enforcement to ensure required EFlows with loss in power generation as
are actually released, as recent studies in EFlow is increased. EFlow
Nepal have found that nearly all hydropower management plans should be
projects do not actually release the required developed in accordance with best
EFlow. practice and should thoroughly
◼ A basin-level strategy should be developed understand aquatic biodiversity within
for collaboratively designing power plants in proposed diversion reaches (IFC
the basin to avoid peaking designs where 2018b). The appropriate EFlow
possible, and to minimize impacts of peaking should be determined based on an
when not. assessment of native fish flow
◼ For any hydropower projects considering requirements and should not be
peaking operation, a robust EFlows based on an arbitrary flow statistic
assessment should be conducted to evaluate (e.g., 10% of the lowest monthly
a range of peaking scenarios in order to flow).
reach a balance between power generation ◼ Peaking operations should consider
and environmental protection – enforcement options for regulating peaking
of EFlow requirements via monitoring and impacts such through a cascade or
fines is needed by the Nepal Government with a regulating dam downstream.
and lenders. ◼ EFlow should take into consideration
◼ Regulation of fishing by communities should the potential for peaking operations
be explored. to disrupt connectivity between the
◼ Subsistence fishing should be allowed where Arun River and important spawning
sustainable, but fishing methods should be tributaries. Maintaining fish
controlled and use of destructive practices connectivity with important
such as electrocution and fishing with nets of tributaries, especially during the
fine mesh sizes should be prohibited. spring fish migration, is critical for
◼ Use of chemicals to catch fish should be maintaining a naturally-reproducing
strongly prohibited. By using chemicals or native fish population.
biocides, both macroinvertebrates and fish ◼ Each HEP should develop a
and their fry are killed. The use of these sediment flushing strategy that
chemicals not only poisons the fish, but they guides the timing of flushing during
are also dangerous for people who eat the the monsoon, when silt loads are
fish. high and flushing is unlikely to cause
alteration of habitats.
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VEC Possible Mitigation and Management Measures
Government-led Measures Project Sponsor-led Measures
◼ There is a need for the development of a ◼ Sustainable sediment mining plans
robust methodology per international should be formulated on a scientific
standards for establishing baselines for basis, to balance the economic
aquatic biodiversity during ESIA process, as benefits of mining with impacts of
well as methodologies for the long-term mining on aquatic ecosystems and to
monitoring of aquatic habitats and achieve a win-win for the economy
biodiversity. A good understanding of river and environment – sand mining sites
ecosystems is required for management of must be selected to avoid sensitive
the impacts of hydropower on fish aquatic habitats (e.g., spawning
populations. This will include aquatic sites) and must be monitored.
biodiversity, composition and distribution of ◼ Establish a reporting commitment in
fish species, and the importance of coordination with the local fishery
connectivity between the main river and and agriculture agency, river
tributaries (IFC 2018b). management agency.
◼ Novel and new survey and monitoring
methodologies should be explored and
tested (e.g., eDNA) and training provided to
hydropower project environmental staff and
government staff.
◼ Capacity building is needed for hydropower
project environmental staff, as well as for
government employees who work with fish
passages in order to ensure that they are
able to monitor and assess the efficacy of
the passages.
◼ The government should review and update
regulations for aquatic habitat protection.
◼ Hatcheries should not be considered a
primary mitigation option as they are unlikely
to help in maintaining wild fish populations.
More research is needed to understand
under what conditions hatcheries can help.
Until then, other mitigation options that are
proven to work should be investigated, and
research should be carried out on how to
supplement fish populations in the wild
through hatcheries.
◼ A basin wide survey should be carried out
with detailed sampling methodology and
community consultations to identify important
fish spawning areas, which are primarily
found along the clear water tributaries of the
Arun River, and measures should be taken
to protect these important spawning areas to
maintain a naturally-reproducing native fish
population.
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9.3 Key Management Recommendations
This section provides some key recommendations regarding managing cumulative impacts within the
Arun River Basin. These represent an action plan for UAHEL to pursue.
◼ River Basin Planning: Even with the adoption and effective implementation of recommended
mitigation and management measures listed in Table 9.1, construction and operation of the over
30 HEPs currently proposed within the Arun River Basin will exceed the carrying capacity of the
river basin and inevitably result in significant adverse cumulative environmental and social impacts.
Over 30 HEPs within this relatively small basin is simply not sustainable. The Government of Nepal
should develop a River Basin Management Plan, which protects key fish spawning tributaries,
minimizes social impacts, and establishes guidelines relative to fish passage, sediment
management, and water quality. There is guidance available for preparing river basin management
plans, such as hydropower by design approach recommended by The Nature Conservancy
(Opperman et al. 2017). This Management Plan should critically review the need for this many
projects and prioritize the most important and most sustainable ones. HEPs with the features listed
in Table 9.2 are not preferred and should be carefully considered before approving.
Table 9.2: Non-Preferred HEP Features
Non-preferred HEP Features Example HEPs in the Arun Basin
HEPs located in the MBNP Core Area and
Apsuwa I, Upper Apsuwa, Upper Isuwa, and Lower
other protected areas and key biodiversity Barun
areas (KBAs)
HEPs requiring long access roads and/or Additional field studies need to confirm access and
transmission line routes, but potentially including Lower
transmission lines that result in significant Barun, Chujung Khola, Upper Ikhuwa Khola Small, Super
habitat fragmentation and/or physical Sabha Khola Small, Sabha Khola-B, Sabha Khola A,
displacement Apsuwa I, Upper Apsuwa, Upper Isuwa
To be determined based on feasibility studies
HEPs with long diversion reaches documenting the proposed length of the diversion reach
HEPs located along important fish
To be determined, but effective fish passage at Sapta
migratory routes without effective fish Koshi High Dam and Lower Arun are very important
passage plans
Additional field studies need to confirm, but potentially
including Chujung Khola, Ikhuwa Khola, Ikhuwa Khola
HEPs located on clear water tributaries Small, Sankhuwa Khola, Lower and Upper Chirkhuwa
that are important for fish spawning Khola, Hewa Khola, Sabha Khola C, Lakhuwa Khola,
Maya Khola, Piluwa Khola
HEPs requiring significant physical Sapta Koshi High Dam Multipurpose Project, possibly
resettlement others based on site-specific field studies
HEPs impacting areas providing important To be determined based on site specific field studies
ecosystem services
◼ Cumulative Impact Assessments – Consider requiring the use of development scenarios in future
hydropower CIAs in Nepal for analyzing future consequences and management options, similar
to what was done in the Kuri Kongri Basin in Bhutan and the Trishuli Basin in Nepal.
◼ MBNP: There are five HEPs planned on the Upper Arun River along the edge of MBNP Buffer Zone
(Kimathanka Arun, UAHEP, Arun-3, Arun-4, and Lower Arun), three planned on tributaries in the
MBNP Core Area (Lower Barun, Apsuwa I, and Upper Isuwa), and four planned on tributaries within
the MBNP Buffer Zone (Upper Apsuwa, Isuwa, Lower Isuwa, and Kasuwa). The need for these
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HEPs within the Core Area and those within the Buffer Zone, but with lower capacity, should be
carefully balanced with their environmental and social impacts, including the construction of project
access roads and transmission lines that contribute to fragmentation.
Support the management initiatives of the MBNP conservation authorities and Community
Conservation Programmes, so that they are better able to cope with the increased pressure from
influx and other impacts. Support should be towards improved park facilities (e.g., offices,
communications, vehicles, and maintenance capacity), infrastructure to access areas for easier
management, boundary demarcation, staff training and equipment, and revision of management
plans, among other things. A mechanism needs to be developed at the level of the Nepal Ministry
of Finance to retain funds generated from hydropower to be allocated to MBNP management
purposes.
◼ Natural forest integrity (impact of transmission lines on birds ): Transmission lines pose a key risk
to birds and all of these HEPs will require the construction of new transmission lines. To minimize
the risk to birds within MBNP and other KBAs, projects should minimize transmission line crossings
of rivers/important bird flyways, be required to share transmission lines corridors, and transmission
line voltages should be designed to accommodate future planned hydropower projects, and all
projects should adopt bird friendly transmission line design to minimize bird collision and
electrocution risk.
◼ Migratory fish: Golden mahseer and other migratory fish species are found within the Arun River
Basin. It is important that fish passage is provided along their migratory routes at proposed HEPs
to maintain their access to critical spawning grounds. It is especially important for the lower main
stem projects to provide effective fish passage, as they could block migratory fish access to a
significant number of spawning areas. This is specifically the case for the Sapta Koshi and Lower
Arun HEPs, as there is documented important spawning habitat upstream from these dams. The
Sapta Koshi, as currently proposed (over 200 m high), is too high for a fish ladder, but other fish
passage options should be explored like trap and trucking or even the creation of a nature-like
fishway, as the topography at this project is more suitable for this option than farther upstream on
the Arun River. The Arun-3 HEP is currently approved without fish passage, which will prevent mid-
range migrants (e.g., common snow trout) from reaching potential habitat upstream. This project is
already under construction, so it is likely too late to retrofit a fish ladder, but options like trap and
trucking should be considered, at least as an adaptive management measure, if monitoring
indicates that the population of common snow trout upstream from Arun-3 HEP is not sustainable.
The approved fish hatchery will likely contribute to the loss of native fish stocks. Tributary streams
important for fish spawning (e.g., Ikhuwa Khola) should be protected (e.g., remain free of
hydropower projects).
◼ Fish and aquatic habitat – The provision of a scientifically-based environmental flow (EFlow) within
the diversion reaches of the proposed HEPs is critical to maintain the ecological integrity of the
Arun River and its tributaries and the ecosystem services they provide. The goal should be to
maintain naturally reproducing populations of all native fish species in each segment of the Arun
River between the main stem hydropower projects. This will require protecting key clear water
tributaries, which are used by common snow trout and golden mahseer for spawning. In the case
of Upper Arun, this would mean protecting Ikhuwa Khola from hydropower development;
◼ River-based livelihoods: Conduct regular socialization, consultation, and monitoring activities with
relevant stakeholders; ensure that the HEP grievance mechanism is well socialized; and develop
relevant community development programs for the HEP-affected people in coordination with
government authorities. Provide livelihood restoration for residents that are affected by conversion
of the Arun River into a series of reservoirs, diversion reaches, and modified flow reaches.
◼ Social cohesion: Develop a strategic plan and provide funding to help local indigenous peoples
(especially upstream from Num) to retain their social identify, cohesion, and heritage in response
to both significant improvements in access to this area and labour influx.
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◼ Cultural heritage: A cultural heritage management plan should be developed to manage impacts
on tangible and intangible cultural heritage resources. In addition, a chance finds procedure should
be developed and implemented for all tangible heritage resources that may be uncovered during
the construction period. The procedure should be disclosed to the EPC, contractors, and
community. HEPs must also consult local leaders before construction activities to discuss cultural
heritage sites and understand when planned ceremonies/rituals take place within/near the
construction area.
◼ Settlement: Maximize the recruitment of local workers where feasible and provide training to
increase the capacity of eligible local people; establish a grievance mechanism (including a gender
based violence [GBV] reporting and management system) accessible for all community groups
(and workers) to report concerns associated with workers; and conduct investigations into the
grievances and address them in a timely manner.
◼ Sediment management (related to water resources): All proposed HEPs must include an effective
strategy for managing sediment, both to sustain their own operations, as well as to maintain
downstream river geomorphic functioning and to minimize the river’s erosion potential. Sediment
flushing during the monsoon season should be considered as part of the sediment management
strategy, but project developers must demonstrate that this sediment will not silt up the project’s
diversion reaches.
◼ Capacity building, regulatory review, monitoring, and enforcement: There is a need for more
capacity building within the key hydropower regulatory agencies in Nepal in terms of evaluating
project impacts, cumulative impacts, and compliance monitoring and enforcement.
- The DoED and MoFE need to carefully review proposed HEPs to ensure they are properly
managing key environmental and social impacts, including physical and economic
displacement, EFlows, fish passage, sediment management, and habitat fragmentation.
- The Ministry of Energy and the MoFE both need capacity building in terms of the assessment
and management of cumulative impacts on VECs such as those caused by UAHEP in
combination with other projects, activities, and stressors.
- There is also a need for effective construction and operation phase monitoring and
enforcement. A recent review of hydropower projects in Nepal (Dangol and Uprety 2019) found
that many that hydropower construction contractors were unaware of required mitigation
measures and that many HEPs were not complying with EIA approval conditions. Recent
studies have found little compliance with required EFlows and required fish ladders are not
designed for the native fish, thereby undermining their likely effectiveness. Further, little
government compliance monitoring or enforcement is occurring, and there are no efforts at
adaptive management. A much more robust compliance monitoring, enforcement program,
and adaptive management is needed to achieve sustainable hydropower in Nepal. The DoED
and MoFE should consider more use of participatory monitoring by local communities of HEP
construction and operation, especially the Arun River Basin which is far from agency
headquarters in Kathmandu and more difficult to monitor because of distance and cost, and
stronger enforcement measures.
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UAHEP CUMULATIVE IMPACT ASSESSMENT APPENDICES
ANNEX A CIA WORKSHOP MINUTES
26 January 2024 Page 161
CIA Consultation Workshop of Upper Arun Hydroelectric Project
11 November, 2019
Workshop Minutes
Background
A Cumulative Impact Assessment (CIA) is being undertaken for the Upper Arun Hydroelectric Project
(UAHEP) in conjunction with the project’s Environmental and Social Impact Assessment. ERM, in
partnership with NESS and TMS, are conducting the UAHEP CIA with a particular focus on:
Cumulative effect of hydropower development in the Arun River basin;
Cumulative effect on the riverine fishery of Arun River basin including rare and endangered species;
and
Cumulative effect on culture and well-being of ethnic minorities whose life is dependent on natural
resources and eco-system services.
UAHEP CIA Workshop Objectives
The purpose of the workshop is to facilitate an open discussion on the potential cumulative impacts of
hydropower projects of the UAHEP and other hydropower projects in the Arun River Basin.
Workshop Summary
A two hour consultation workshop of the UAHEP CIA was held on 11 November, 2019 in Hotel Annapurna,
Kathmandu. Representatives from UAHEP, DOED, WECS, NARC, and Makalu Barun National Park were in
attendance. The list of the participants is annexed at the end of this workshop summary report.
Mr. Ram Chandra Poudel, Project Manager of Upper Arun Hydroelectric Project gave the welcome
speech. He gave brief description on the ongoing project activities, environmental and social impact of
the project, recommended measures, CIA strategy, assessment and management.
1
Ms. Christine Bryant from ERM presented a brief overview of the CIA process (according to IFC’s 6-step
CIA process) and requested input from the participants for each of the 6 steps as summarized below:
Step 1a: Preliminary VECs:
o Water resources, especially changes in the flow regime;
o Fish and aquatic habitat, especially the common snow trout, which is the most abundant
migratory fish found in the Upper Arun River;
o Forest loss and fragmentation, including effects on birds and wildlife species;
o Livelihoods – impacts on traditional and river dependent livelihoods;
o Social Cohesion - changes in traditional lifestyles, use of natural resources, ecosystem
services, cultural practices, differential effects on women; and
o Makalu Barun National Park (MBNP – effects on MBNP core and buffer areas).
Step 1b: Spatial boundary for the UAHEP CIA: encompasses the Arun River Basin from the
Nepal/Tibet border to the confluence of the Arun River and Sabha Khola. The CIA study area is
situated in Sankhuwasabha District.
Step 1c: Temporal Boundary for the UAHEP CIA: The temporal boundary for CIA analysis is
typically related to the life expectancy of the identified project, in this case UAHEP. For other
projects, we typically include those which will reasonably happen within the next 10-15 years
Step 2: Identifying hydropower developments and stressors in the UAHEP CIA Study Area:
o Apsuwa, Arun III, Chujung Khola, Ikhuwa Khola, Kimathanka Arun, Lower Arun, Lower
Barun Khola, Lower Isuwa Khola, Sabha Khola A, Upper Ikhuwa Khola
Step 3: Establishing the VEC Baseline
Steps 4,5 and 6: Assessing cumulative impacts and mitigation measures
Key questions and issues raised by the participants:
It was pointed out that Arun IV project was missing under CIA study area.
Project licensed within the recent 2 months of Barun Khola project should be included as well.
It was suggested to update the capacity table and include Arun IV and Barun Projects
It was suggested to give official letter to DoED in order to request of any type of information.
It was highlighted that Makalu Barun Conservation Area is a buffer zone area, focus should be
given to the conservation of the critical species of that area.
ERM described that help from relevant department for hydrological data will be very helpful.
Impact on Transmission line and Koshi Highway corridor should be included in CIA
It was questioned on who monitors/ address the issues of obstruction in dewater zone, best
management practice and the uncertainty.
It was suggested to include impact from other projects and identify the mitigation measures.
It was recommended for the formation of basin level committee since Upper Arun cannot take
the responsibility of the whole other impacts, same was done in case of Upper Trishuli Project.
It was suggested to considered Water conservation act of Nepal in CIA.
It was recommended to have Basin level plan to mitigate cumulative impacts .
It was pointed out that the scale of operation has significant impact on the CIA process.
Queries were made whether CIA is mandatory or not and whether CIA is mentioned in any legal
reference in Nepal or not?
It was elaborated that CIA is mentioned in WECS draft.
2
Queries were made on the legal requirement of CIA.
It was questioned whether EIA is required even after CIA or not.
Discussion on the need of fish ladder and fish hatchery as an appropriate fish impact mitigation
measures by all the projects.
It was suggested that for the legalization of the project document, one should request for
recommendation from the conservation area.
It was suggested to have consensus of local government in the CIA process
The questions and queries made by the participants were responded by the team of experts from ERM.
Similarly the comments and suggestions received from the participants were well taken by the team which
will be incorporated in the UAHEP CIA.
In his closing remark, Mr. Ram Chandra Poudel expressed appreciation to the participants of the workshop
for their active participation and contributions by providing valuable comments and suggestions.
3
ANNEX B DOWNSTREAM CIA CONSULTATIONS FIELD REPORT
26 January 2024 Page 165
Upper Arun HEP
Cumulative Impact Assessment
Workshop
Kathmandu, Nepal
11 November, 2019
in association with:
NESS
© Copyright 2019 by ERM Worldwide Group Limited and/or its affiliates (‘ERM’). All Rights Reserved.
No part of this work may be reproduced or transmitted in any form or by any means, without prior
written permission of ERM.
The business of sustainability
Agenda
Time Agenda
10:30 – 10:45am Welcome and Introductions
10:45 am – 12:15 pm UAHEP CIA
• Overview of the CIA Process
• Discussion of the Valued Environmental and Social Components for the UAHEP CIA
12:15 – 12:30 pm Closing Note
www.erm.com UAHEP CIA Workshop 11 November 2019 2
Introductions
Cumulative Impacts Assessment Overview
The objectives of a CIA are to:
analyze the potential impacts and risks of proposed projects in the context of the potential effects of
other human activities and external stressors on VECs (Valued Environmental and Social
Components) over time, and
propose measures to avoid, reduce, or mitigate such cumulative impacts and risk, to the extent
possible
For practical reasons, the identification, assessment, and management of cumulative impacts are limited
to those effects generally recognized as important on the basis of scientific concerns and/or concerns of
affected communities – VECs
CIA is another environmental and social risk management tool, like a Environmental and Social Impact
Assessment (ESIA), but they are different….
www.erm.com UAHEP CIA Workshop 11 November 2019 4
ESIA vs. CIA
ESIA CIA
An ESIA describes the setting, impacts, and A CIA focuses on VECs, assessing how the
mitigation actions for a specific project. VECs will be impacted under scenarios of
Focused in the project’s area of influence. current, planned, and future projects and
stressors. A CIA assesses selected VECs in
an expanded spatial and temporal boundary.
Source: World Bank/IFC, 2013
www.erm.com UAHEP CIA Workshop 11 November 2019 5
World Bank/IFC 6-Step CIA Process
www.erm.com UAHEP CIA Workshop 11 November 2019 6
VECs
Environmental and social components considered as important by the scientific community and/or
concerns of affected communities. Examples:
Physical features, habitats, wildlife populations (e.g., biodiversity, water supply)
Ecosystem services (e.g., protection from natural hazards, provision of food)
Natural processes (e.g., water and nutrient cycles, microclimate)
Social conditions (e.g., community health, economic conditions)
Cultural heritage or cultural resources aspects (e.g., archaeological, historic, traditional sites)
www.erm.com UAHEP CIA Workshop 11 November 2019 7
Step 1: Preliminary VECs Identified for the
UAHEP CIA
Preliminary VECs:
1. Water resources, especially changes in the flow regime;
2. Fish and aquatic habitat, especially the common snow trout, which is the most abundant
migratory fish found in the Upper Arun River;
3. Forest loss and fragmentation, including effects on birds and wildlife species;
4. Livelihoods – impacts on traditional and river dependent livelihoods;
5. Social Cohesion - changes in traditional lifestyles, use of natural resources, ecosystem
services, cultural practices, differential effects on women; and
6. Makalu Barun National Park (MBNP – effects on MBNP core and buffer areas.
www.erm.com UAHEP CIA Workshop 11 November 2019 8
Step 1: Spatial
Boundary
UAHEP CIA Study Area
Objective: Establish a spatial boundary that
encompasses the geographic extent of impacts (from
other past, present, and predictable future developments)
that influence VEC conditions throughout the time period
during which UAHEP impacts will occur
The spatial boundary for this CIA encompasses the Arun
River Basin from the Nepal/Tibet border to the confluence
of the Arun River and Sabha Khola. The CIA study area is
situated in Sankhuwasabha District.
UAHEP CIA Workshop 11 November 2019 9
Step 1: UAHEP CIA Temporal Boundary
Objective: Establish a temporal boundary that considers past, existing and reasonably
foreseeable future activities/projects
Temporal Boundary for the UAHEP CIA
The temporal boundary for the CIA analysis is typically related to the life expectancy of
the identified project, in this case UAHEP. For other projects, we typically include those
which will reasonably happen within the next 10-15 years
www.erm.com UAHEP CIA Workshop 11 November 2019 10
Step 2: Identify Projects and Stressors in the
UAHEP CIA Study Area
Objectives:
Identify other past, existing, or planned projects within the boundaries
Identify presence of natural influences / stressors
Questions to answer:
Are there any other existing or planned activities affecting the same VEC?
Are there any natural forces / phenomena affecting the same VECs?
Rules of Thumb:
Based on existing information and available sources
Classify projects by common characteristics
Obtain, to the extent possible, enough information to be able to estimate their impacts on VECs
Consider the certainty (or uncertainty) of future or planned activities
www.erm.com UAHEP CIA Workshop 11 November 2019 11
Step 2: Identify HEPs in the CIA Study Area
Project License Status Capacity River Municipality/District Promoter
(MW)
Apsuwa I Survey - Issued 23 Apsuwa Makalu,Yafu (Sankhuwasabha) Ram Janaki Hydropower Pvt. Ltd
Arun III Generation - 900 Arun Diding,Num,Makalu,Matsya, Satluj Jal Vidyut Nigam Limited
Issued Pokhari,Mangtewa,Pathibhara
(Sankhuwasabha)
Chujung Khola Survey - Issued 48 Chujung Chepuwa (Sankhuwasabha) Sangrila Urja Pvt. Ltd
Khola
Ikhuwa Khola Survey - Issued 30 Ikhuwa Makalu Upper Arun Hydro Electric Limited
Isuwa Khola Survey – Issued 97.2 Isuwa Khola Makalu (Sankhuwasabha) KBNR Isuwa Power Ltd.; Dolakha
Nirman Company Pvt. Ltd.
Kimathanka Arun Survey – Issued 450 Arun Keemathnka,Chepuwa (Sankhuwasabha) Vidhyut Utpadan Company Limited
Lower Arun N/A 400 Arun Bhot Khola Rural Municipality,
Sankhuwasabha
Lower Barun Khola Generation – 132 Barun Khola Bhot Khola Rural Municipality, Ampik Energy Pvt Ltd
Applied Sankhuwasabha
Lower Isuwa Khola Survey – Issued 37.7 Isuwa Khola Makalu (Sankhuwasabha) Isuwa Energy Pvt. Ltd
Sabha Khola A Survey – Issued 9.55 Sabha Khola Sabha Pokhari (Sankhuwasabha) Sankhuwasabha Power Development
Pvt.Ltd
Upper Arun Survey – Applied 1,040* Arun Pathibhara,Pawakhola (Sankhuwasabha) Upper Arun Hydro Electric Limited
Upper Ikhuwa Khola Survey - Issued 9.6 Ikhuwa Khola Pawakhola (Sankhuwasabha) Khadga Bdr Karkee
Small
Total 3,147.05
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Step 2: HEPs in the UAHEP
CIA Study Area
Objective:
Identify other past, existing, or planned projects
within the boundaries
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Step 2: Stressors in the UAHEP CIA Study Area
Stressors: sources or conditions that could affect or cause physical, biological, or social
stress on VECs
Potential stressors include:
Climate change
Natural disasters
Deforestation
Landslides
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Step 3: Establish VEC Baseline
Objectives:
Define existing condition of the selected VECs
Understand its potential reaction to stress - resilience / recovery time
Assess trends
Questions to answer:
What is the existing condition of the selected VECs?
What are the indicators used to asses such condition?
What additional data is needed?
Who may already have this information?
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Step 3: Establish VEC Baseline
VEC Indicators:
To define appropriate indicators, one needs to understand the VEC’s condition (is the VEC condition
stable, deteriorating, improving?)
Indicators help assess VEC threshold – state beyond which the VEC condition is unstainable, unviable
Examples :
Total land cover for habitat fragmentation
Macroinvertebrate population for aquatic habitat conditions
Total number of incidents for community health
Rules of Thumb:
Defining indicators, trends and thresholds can be data intensive – but many sources available (e.g.,
EISA, universities, research institutes, government agencies, historical societies, NGO, individuals)
Refer to existing regulations (e.g. water quality/ air quality)
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Step 3: Establish VEC Baseline
VEC Baseline Condition & Key Key Indicators Key Sources of Information
Components
Water resources, especially
changes in the flow regime
Fish and aquatic habitat
Forest loss and fragmentation,
including effects on birds and
wildlife species
Livelihoods – impacts on
traditional and river dependent
livelihoods
Social Cohesion - changes in
traditional lifestyles, use of
natural resources, ecosystem
services, cultural practices,
differential effects on women
Makalu Barun National Park
(MBNP – effects on MBNP core
and buffer areas.)
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Steps 4, 5, 6 – Assessing Cumulative Impacts &
Mitigation Measures
VEC Key Stressors Key Impacts Suggested Mitigation
Measures
Water resources, especially
changes in the flow regime
Fish and aquatic habitat
Forest loss and fragmentation,
including effects on birds and
wildlife species
Livelihoods – impacts on
traditional and river dependent
livelihoods
Social Cohesion - changes in
traditional lifestyles, use of
natural resources, ecosystem
services, cultural practices,
differential effects on women
Makalu Barun National Park
(MBNP – effects on MBNP core
and buffer areas.)
www.erm.com UAHEP CIA Workshop 11 November 2019 18
Closing Note
Thank you
The business of sustainability
ANNEX C NEPAL ADMINISTRATIVE AND LEGAL FRAMEWORK
26 January 2024 Page 186
Constitution
Constitution of Nepal, 2015
Plans
National Water Plan, 2005
Brief Guideline for Preparation of Water Use Master Plan, 2017
Strategies
Agriculture Development Strategy 2015–2035
Forest Sector Strategy 2016–2025
National Energy Crisis Reduction and Electricity Development Decade, 2015
National Energy Strategy of Nepal, 2013
National Water Resources Strategy, 2002
Rural water supply and Sanitation National Strategy, 2004
Policies
Climate change Policy 2019
Draft Water Resources Policy, 2019
Forest Policy,2000
Hydropower Development Policy (HDP), 1992 and Hydropower Development Policy, 2001
Irrigation Policy, 2013
Land Acquisition, Resettlement and Rehabilitation Policy, 2015
Land Use Policy, 2015
National Agriculture Policy, 2004
Public-Private Partnership Policy, 2015
Water-induced Disaster Management Policy, 2015
Acts
Aquatic Protection Act, 1960
Civil Code, 2017
Consumer Protection Act, 1999
Criminal Code, 2017
Development Board Act, 2706
Disaster Risk Reduction and Management Act, 2017
Draft Irrigation Act, 2015
Draft Water Supply and Sanitation Act, 2018
Electricity Act, 1992
Environment Protection Act, 2019
Essential Commodity Protection Act, 1955
Forest Act, 1993 and Forest Act, 2019
Guthi Corporation Act, 1976
Industrial Enterprises Act, 1992
Inter-governmental Fiscal Management Act, 2017
26 January 2024 Page 187
Land Acquisition Act, 1977
Lands Act, 1964
Land Use Act, 2019
Local Government Operation Act, 2017
Natural Resources and Fiscal Commission, 2017
Nepal Electricity Authority Act, 1984
Nepal Electricity Regulatory Commission Act, 2017
Public Private Partnership (PPP) and Investment Act, 2019
Water Resources Act, 1992 and Draft Water Resources Act, 2019
Water Supply Management Board Act, 2006
Provincial Acts
Irrigation Act, 2018 (P-1)
Rules
Drinking Water Rules, 1998
Electricity Rules, 1993
Environment Protection Rules, 2020
Forest Rules, 2020
Irrigation Rule, 2000
Rafting Rule, 2006
Water Resources Rule, 1993
Guidelines/Directives/Manuals/ Working Procedures
Directives for Use of Forest for National Prioritized Projects, 2017
Guidelines to Provide Land for Construction of Infrastructure Projects in Conservation Areas 2024
Directives on Licensing of Hydropower Projects, 2016
Drinking Water Service Operation Directive, 2012
EIA/IEE Working Procedure for Hydropower and Transmission Lines, 2016
Hydropower Environmental Impact Assessment (EIA) Manual, 2018
Gender Equality and Social Inclusion Mainstreaming Guideline for Irrigation and Water Induced Disaster
Prevention Sectors, 2014, Ministry of Irrigation
Guidelines for Study for Hydropower Projects, 2003
Land Ceiling Exemption Order, 2017
Local Energy Development Directive, 2017
National Drinking Water Quality Standard, 2005
National EIA Guideline, 1993
26 January 2024 Page 188
ANNEX D FISH SPECIES POTENTIALLY PRESENT IN THE ARUN
BASIN
26 January 2024 Page 189
Fish Species Potentially Present in the Arun River Basin
S/N Image Scientific Name English Name/ IUCN Red- Status in Max. Length Migratory Value to local
Local Name List Status Nepal / Weight behaviour communities
1 Amblyceps mangois Torrent catfish/ LC Endemic, R 125mm Mid No known
Baljung, Bokshi distance commercial
macho importance
2 Anguilla bengalensis Longfin NT 2,000mm / Long Commercial
freshwater eel, 6kg distance fisheries; Likely for
Indian Mottled aquaculture;
Eel/ gamefish; TP, PR
Raj Bam, Rem
3 Barbus Chilinoides = Dark mahseer VU 600 – 700mm Long valuable
Naziritor chelynoides distance
4 Barilius barila Barna Baril / LC 100mm Resident Used as bait
Faketa Chahale
5 Barilius barna Barna Barile/ LC C 150mm Resident Minor commercial
Pati Pattaure, importance to
Titerkane, Faketa fisheries
6 Barilius bendelisis Hamilton’s Barila/ LC C 227mm Resident Commercial
Chiple Faketa, importance to
Gurdere fisheries
7 Barilius shacra Chacra Baril/ LC Uncommon 130mm - No known
Fakete CL commercial
importance
S/N Image Scientific Name English Name/ IUCN Red- Status in Max. Length Migratory Value to local
Local Name List Status Nepal / Weight behaviour communities
8 Barilius vagra Vagra Baril/ LC Uncommon 156mm Resident No known
Lam faketa commercial
importance
9 Balitora brucei NT Unknown Small Resident No known
˂ 100mm commercial
importance
10 Botia Geto= Botia dayi Bengal loach LC CL, PR 150mm Commercial:
Hora=Botia dario Necktie Loach, aquarium species
Striped Stone
Loach/
Bothn
11 Botia almorhae= B. Yoyo-Loach, NE Uncommon, 154mm Resident Commercial:
lohachata= B. grandis= B. Tiger Loach/ CL aquarium species
rostrata Baghi, Getu Slow warter
12 Channa gachua Dwarf snakehead LC small No known
commercial
importance.
Aquarium fish
13 Clupisoma garua Garua Bachcha, LC Uncommon 609mm / 3kg Long Commercial:
Guarchcha/ distance fisheries; gamefish
Jalkapoor, Baikha
14 Clupisoma montana Kocha Garua/ LC Uncommon 290mm - No known
Jalkapoor commercial
importance
15 Crossocheilus latius latius Gangetic Laita, DD C 150mm Resident No known
Stone Roller/ commercial
Lohari, Mate importance
Buduna
S/N Image Scientific Name English Name/ IUCN Red- Status in Max. Length Migratory Value to local
Local Name List Status Nepal / Weight behaviour communities
16 Glyptosternum blythii Dwarf Catfish, DD unknown 70-80 mm short No known
=Exostoma blythii Tilchabre distance commercial
= Myersglanis blythii importance
17 Euchiloglanis hodgarti= Catfish LC unknown No known
Parachiloglanis hodgarti commercial
importance
18 Garra annandalei Buduna, stone LC Uncommon 150mm Resident No known
sucker, commercial
importance
19 Garra gotyla gotyla Stone Sucker/ LC C 145mm Resident Minor commercial
Nakato fishery importance
20 Garra rupecula = Garra Buduna NT Unknown small resident low
rupicola
21 Glyptothorax cavia Vedro LC CL 175mm resident Minor commercial
fishery importance
22 Glyptothorax indicus Catfish LC Fast flowing 120mm No known
Capre rivers commercial
importance
23 Glyptothorax pectinopterus Capre LC Uncommon 180mm Resident No known
commercial
importance
24 Glyptothorax telchitta Telcapre LC Common 152mm Resident Minor commercial
fishery importance
S/N Image Scientific Name English Name/ IUCN Red- Status in Max. Length Migratory Value to local
Local Name List Status Nepal / Weight behaviour communities
25 Glyptothorax trilineatus Telcapre LC common resident No information
26 Hetropneustes fossilis
27 Labeo angra Thilke LC 220mm Subsistence
fisheries
28 Labeo dero (Sinilabeo dero) Kalebans, River LC C 750mm Mid Commercial
Rohu/ Gurdi, distance fisheries; usually
Bashari used as bait
29 Mastacembelus armatus Chuche Bam LC resident -
30 Neolissochilus Katli/ Katle NT GF, TP 1,200mm / 11 Mid Fisheries:
hexagonolepis kg distance Commercial
Aquaculture:
Commercial
Gamefish: Yes
31 Noemacheilus bevani Gadela Resident
32 Noemacheilus botia = Loach LC Common small Medicine
Acanthocobitis botia Hilly aquarium
clearwater
rivers
33 Pseudecheneis crassicauda Kabre DD CL, PR 140mm No known
commercial
importance
S/N Image Scientific Name English Name/ IUCN Red- Status in Max. Length Migratory Value to local
Local Name List Status Nepal / Weight behaviour communities
34 Pseudecheneis sulcatus Sulcatus / Kabre LC CL, PR 200mm Resident No known
commercial
importance
35 Psilorhynchus Stone carp, Tite LC Endemic, 200mm No known
pseudecheneis machha CL, PR commercial
importance
36 Puntius sarana Oliv barbe LC 300 mm resident Not known
37 Schistura multifaciata = LC 100 mm resident No interest
Nemacheilus rupicola
38 Schistura rupecula Stone loach LC CL, PR 85mm No known
Bhotee Gadelo commercial
importance
39 Schistura savona LC small Resident No known
commercial
importance
40 Schizothoraichthys Pointednosed LC C 500mm Mid Commercial:
progastus Snowtrout/ distance fisheries; gamefish
Chuche Asla
41 Schizothorax plagiostomus Golden NE Declining 600mm / 2kg Mid Commercial:
Snowtrout, distance fisheries
Spotted
S/N Image Scientific Name English Name/ IUCN Red- Status in Max. Length Migratory Value to local
Local Name List Status Nepal / Weight behaviour communities
42 Schizothorax richardsonii Bluntnosed VU Declining 600mm / 2kg Resident Commercial:
Snowtrout/ Buche fisheries; gamefish
Asla, Budhe Asla
43 Tor putitora Putitor Mahseer/ EN GF, PR, TP 1,800mm / Long Commercial
Pahale Sahar 48kg distance fisheries;
Golden Mahseer, aquaculture;
Mansar, Ratar gamefish;
aquariums
44 Tor tor Tor Mahseer/ DD GF, PR, TP 2,000mm / 9 Long Commercial
Falame Sahar kg Distance fisheries;
aquaculture;
gamefish
ANNEX E ESTIMATED DISTRIBUTION RANGE OF SELECT FISH SPECIES
IN THE ARUN BASIN
26 January 2024 Page 196