Community- and Nature-Based Solutions for Integrated Urban Flood Risk Management Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators Table of Contents Acknowledgments 2 1. Introduction 4 ©2020 The World Bank 2. What Is a Mini Studio? 8 International Bank for Reconstruction and Development The World Bank Group 3. Why a Mini Studio? 11 1818 H Street NW, Washington, DC 20433 USA May 2020 4. Key Elements of a Mini Studio 14 4.1 Understanding the Urban Context and Challenges 14 RIGHTS AND PERMISSIONS 4.2 Setting a Flood Management Target 16 The material in this work is subject to copyright. Because The World Bank encourages 4.3 Developing a List of Community- and Nature-Based Measures 20 dissemination of its knowledge, this work may be reproduced, in whole or in part, for noncommercial purposes as long as full attribution to this work is given. 4.4 Designing Innovative Solutions for Urban Flood Resilience 26 4.5 What Comes after the Mini Studio 30 Any queries on rights and licenses, including subsidiary rights, should be addressed to World Bank Publications, The World Bank Group, 1818 H Street NW, Washington, DC 20433, USA; e-mail: 5. How to Prepare and Implement a Mini Studio 32 pubrights@worldbank.org. Step 0: Preparing for the Mini Studio 33 Step 1: Basic Overview of the Mini Studio Exercise 36 CITATION Please cite the report as follows: World Bank and Labs for Rainwater Society Japan. 2020. Step 2: Get into Teams and Explore the Neighborhood 38 Mini Studios for Water- Sensitive Urban Design: A Handbook for Organizers and Facilitators. Step 3: Explore the Design Site 40 Washington, DC: World Bank. Step 4: Group Work—Develop a Proposal for a Flood-Resilient Neighborhood 42 COVER IMAGE Step 5: Pin-Up Presentations and Reflection 44 A schematic graphic of rainwater flow in an urban context. Various infrastructural and land use planning strategies mitigate the risks of urban runoff through infiltration, storage, and conveyance. 6. Experiences and Lessons from Past Mini Studios 45 By Kenya Endo 6.1 Technical Deep-Dive Session in Sumida Ward, Tokyo 45 6.2 Integrating Nature-Based and Green Solutions for Urban Flood Risk Management, 56 Design Charrette, Bogor, Indonesia 6.3 Tips and Recommendations for Future Mini Studios 61 7. References 63 Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 2 Acknowledgements This Handbook was developed through a partnership between the World Bank Tokyo Disaster Risk Management Hub, the World Bank Urban Floods Community of Practice, and Labs for Rainwater Society, Japan. It was prepared by a team led by Jolanta Kryspin-Watson, with Shoko Takemoto, Tomoki Takebayashi, Kenya Endo, Zuzana Stanton- Geddes, and Robin Lewis. As World Bank Group peer reviewers, Dixi Mengote-Quah and Jian Vun provided invaluable comments and suggestions. Thanks also to external advisor Yukihiro Shimatani of Kyushu University for review and guidance. The Handbook also benefited from the guidance and contributions of the following Japanese experts: Michiru Sasagawa, Rain City Support and People for Rainwater, and Takanori Fukuoka, Tokyo University of Agriculture. This publication was developed with support from the Japan–World Bank Program for Mainstreaming DRM in Developing Countries, which is financed by the Government of Japan and managed by the Global Facility for Disaster Reduction and Recovery (GFDRR) through the Tokyo Disaster Risk Management Hub. 3 Photograph 1: Urban Flooding Across the World Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 4 1. Introduction Globally, floods are the most frequent and damaging natural hazard. Between 1998 and 2017, floods led to economic damages exceeding $600 billion, affected more than 2 billion people, and resulted in around 142,000 fatalities (Wallemacq, Below, and McLean 2018). Compounded by rapid urbanization and climate change, these losses will likely increase, especially in fast-growing cities. To help manage the impact of flooding on people and economies, the World Bank provides technical assistance, advisory services, and financing to its client countries through a range of resilient urban development initiatives. These efforts increasingly promote an integrated approach to flood risk management that combines engineered and nonengineered measures, as well as traditional and innovative community- and nature-based solutions. By integrating these diverse measures, cities can better adapt to different types of flood risks and scenarios, as well as enhance their capacities to plan for uncertainties and extreme weather events that may increase under conditions of climate change. Successful cases of integrated urban flood risk management (IUFRM) have demonstrated significant results not only in reducing the negative impacts of urban floods, but also in enhancing ecological services and raising community awareness of flood risk and ways to mitigate it. Various case studies of IUFRM are highlighted in Learning from Japan’s Experience in Integrated Urban Flood Risk Management: A Series of Knowledge Notes (World Bank 2020). Sources: Grenet 2015 (top); Gonzalez 2016 (bottom). Note: Heavy storm events often exceed the designed management capacity of cities’ infrastructure. The integrated urban flood risk management approach not only minimizes damage to lives and economies, but also enhances ecological services. 5 Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 6 Photograph 2: Rain Garden, Natural Drainage, and Floodable Play Field Integrated with High-Rise Public Housing in Punggol District, Singapore In this context, there is growing interest in rethinking the way we plan for urban flood resilience—to explore and integrate a wider range of approaches and solutions, including community- and nature- based approaches. Yet there is limited understanding and utilization of tools and resources for city planners to carry out these integrated planning and prioritization processes. To help fill this gap, this Handbook showcases a multistakeholder planning and awareness-raising “Mini Studio” exercise to kick-start and facilitate the integrated planning, prioritization, and design process of urban flood resilience initiatives. Drawing upon the experiences and lessons learned from past Mini Studio exercises implemented by the World Bank in Tokyo, Japan, and Bogor, Indonesia, the Handbook outlines key principles and design exercises that can be tested and examined in any city across the world. The Handbook aims to serve as a step-by-step guide and resource for technical and nontechnical audiences, government officials, city planners and practitioners, academics, community groups, and others interested in innovative approaches to promoting urban flood resilience that integrate the needs of various stakeholders and combine traditional measures with innovative community- and nature-based solutions. Source: Ramboll Studio Dreiseitl, Singapore. Note: The development explores a nature-based approach to managing stormwater runoff holistically with added ecological, aesthetic, and communal benefits. 7 Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 8 Photograph 3: Various Activities of a Mini Studio, including Site Excursions, Design Exploration, and a Pin-Up Session for Sharing Design Ideas 2. What Is a Mini Studio? The term “studio” or “design studio” typically refers to a set of problem-solving exercises undertaken by students and professionals involved in architecture and urban design. Gathering in the same space together, design students, instructors, and professionals collaboratively investigate a common problem. A “Mini Studio for Water-Sensitive Urban Design” is an adaptation of this interactive and hands-on learning experience, and aims to provide an opportunity for participants to: • See and learn, first-hand, various techniques available for managing rainwater in urban areas. • Explore and experience the challenges and opportunities involved in progressing toward ambitious flood management goals. • Create a simple flood-resilient neighborhood design proposal. Thus, the Mini Studio is designed to facilitate participants’ hands-on interactions, creativity, and problem-solving skills to overcome complex urban flood risk management issues. Participants are asked to use their imagination and design know-how to come up with new ways to solve complex urban planning challenges. In the course of the studio exercise, all participants are encouraged to chip in ideas, build robust strategies, and create simple drawings and models to visually communicate solutions based on predetermined themes and parameters. Source: World Bank Global Facility for Disaster Reduction and Recovery (GFDRR). 9 Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 10 Photograph 4: Various Projects Led by LRwS Roof Solar panel for water heating Roof gutter Water containers A network of Japanese researchers called the Labs for Rainwater Society (LRwS) have been Remove (for firefighting) first flush implementing this Mini Studio exercise as part of their Rainwater Coordinator Training Program since 2015. Through the program, LRwS trained a cohort of Japanese professionals working in Pump national and city governments, urban design and engineering companies, academia, and civil society groups. These trainees have been equipped with enhanced understanding of how to plan, Footbath design, and implement various integrated approaches to urban stormwater management for the Rainwater benefit of society. reuse Bathtub for babies (for water reuse) Mini Studio exercises are mainly twofold: an exploration of design ideas toward the creation of Lush garden plants to enhance infiltration a flood-resilient neighborhood, and hydraulic calculations quantifying the effectiveness of the Handmade infiltration trench using water container and crushed stone proposed stormwater management techniques. These two elements feature participatory planning practices common in Japan, the United States, Australia, and Singapore,1 with the additional value of leveraging scientific and technical evidence to jointly measure and understand the impact of flood risk mitigation ideas. The “Mini Studio for Water-Sensitive Urban Design” showcased in this Handbook draws upon the methodology developed by LRwS in Fukuoka, Japan, and adapts its tools and exercises to be more broadly applicable and relevant for adoption by global audiences. Source: LRwS. Note: Home renovation prototype with ideas for reusing rainwater for daily activities, such as footbaths and water 1 features (top and bottom left), a rain garden in a cafe, and streetscapes in collaboration with community members For example, refer to participatory planning cases explored after Superstorm Sandy in the United States: https:// (bottom right). stormrecovery.ny.gov/community-reconstruction-program; and neighborhood-scale community engagement initiatives in Singapore: http://participateindesign.org/. 11 Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 12 Breaking barriers A Mini Studio fosters collaboration between practitioners from different areas of expertise and sectors, including: the national and local government; various public sector departments, such as river and water resources, roads, drainage, environment, parks, tourism, education, and health; academia; and the private sector, as well as community members wanting to gain a deeper 3. Why a Mini Studio? understanding of new approaches to urban flood resilience. Topics include innovative measures and solutions, such as green infrastructure and community- and nature-based approaches. What Does a Flood-Resilient Neighborhood Look Like? Fostering imagination A Mini Studio is a great way to initiate dialogue with diverse stakeholders on the details of design challenges and opportunities. For our purposes, its strengths lie in making the concept of “flood resilience” something more concrete and tangible at a neighborhood scale, so participants can better understand and conceptualize measures and policies proposed at the city or national scale. A Mini Studio normally examines an actual site located close to where the exercise takes place. Participants are encouraged to “think outside the box” and to tap into their imaginations to apply A Mini Studio is often implemented as a stakeholder consultation or capacity-building process that creative and exciting solutions in their design proposals. This exercise provides an opportunity for is part of the planning, prioritization, and/or design of a flood management initiative. It can also participants to temporarily set aside various real-life limitations and constraints, and thus gain new be implemented as part of a technical training program for professionals, students, and community perspectives, ideas, and realizations. members. The key benefits and objectives of incorporating a Mini Studio exercise as part of urban flood Exploring and combining resilience planning include the following. alternative methods With diverse stakeholders working together to exercise not only their expertise but also their creativity and imagination, the Mini Studio provides a chance to explore and integrate alternative methods of fostering urban flood resilience, including solutions that have rarely been implemented or considered as flood risk management measures, such as green infrastructure and community- and nature-based solutions. By collaborating with diverse stakeholders, participants often gain understanding of new approaches and methods for water-sensitive urban design, and also expand and deepen the understanding of the risks and benefits of urban flood resilience. 13 Figure 1: Basic Hydraulic Cycle in a Natural Environment and as Affected by Urbanization Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 14 Rainwater Return to natural water cycle 4. Key Elements of a Mini Studio A Mini Studio for Water-Sensitive Urban Design, with a focus on applying community- and nature- based solutions, particularly for stormwater management, touches on the following five topics: Low rainwater runoff • Understanding the Urban Context and Challenges • Setting a Flood Management Target • Developing a List of Community- and Nature-Based Measures • Designing Innovative Solutions for Urban Flood Resilience High • What Comes after the Mini Studio Natural Surface: infiltration High Rainwater Management Capacity These are further elaborated in the following sections. 4.1 Understanding the Urban Context and Challenges Rainwater Gathering background information on the study site, city, local residents and cultures, and environmental features, such as those relevant to urban hydrology, is an important first step of the Return to natural water cycle Mini Studio exercise. Key information required in the urban context include: • The site’s exposure to natural hazards—including vulnerability and resilience to historical Large rainwater runoff flooding due to heavy rainfall, river overflow, and coastal weather events. • Urban development—including urban density, transportation networks (roads, access paths, cycleways, public transit), buildings and structures, cultural landmarks, and heritage sites. • Landscape, land use, and infiltration capacity—including elevation, slope direction, site grading, location and condition of land, land use, green spaces, and existing and historic creeks and Limited water bodies that may affect the way water moves and infiltrates. Urban Surface: infiltration Low Rainwater Management Capacity Source: Kenya Endo. Note: The runoff volume increases due to development—that is, the conversion of vegetated Limited land into paved surfaces and built-up areas. infiltration 15 Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 16 4.2 Setting a Flood Management Target Based on the context and challenges of the site and city, a flood management target for the Mini Studio exercise needs to be selected. Local or national flood management plans, if available, could Figure 2: Degrees of Rainfall Intensity and Their Typical Effects on City Residents serve as a good reference in setting this target. Nature- and community-based measures promoting urban flood resilience usually focus on heavy rainfall. Key principles of setting stormwater How intense is 75 mm/hr rainfall? management targets include the following. Slightly Strong Rain Strong Heavy Rain Very Heavy Rain Intense Rain Design rainfall (storm) 10–20 mm/hr 20–30 mm/hr 30–50 mm/hr 50–80 mm/hr above 80 mm/hr Design rainfall is the extreme rainfall event that the proposed flood resilience measure aims to manage, described in terms of intensity (in millimeters per hour, mm/hr), duration (in hours or days; for example, a storm lasting one hour), and frequency (based on an annual recurrence interval or “return period,” such as once in 100 years [1-in-100-year event]). For example, in central Tokyo, 1-in-20-year rainfall levels are: 75 mm/hr or 253 mm/day, which is set as a 30-year stormwater management target, and 97 mm/hr or 327 mm/day, which is set as a long-term target (Tokyo Rain bounces off the Pouring rain that Heavy rain like a Rain falling like a Oppressive rain that Metropolitan Government 2014). ground and people’s drenches clothing bucket of water waterfall. Where it is stifling. feet get wet. even if people use an turned over. The road splashes, surfaces umbrella. becomes like a river. look whitish. Stormwater runoff reduction targets Stormwater runoff is the volume of water that is discharged from a site, often expressed in terms of Source: Bureau of Urban Development, Sumida Ward 2018. flow rate (volume per unit time, such as cubic meter [m3]/second). This is the net amount of rainfall Note: mm/hr = millimeters per hour. ending up in the urban drainage system, which is not absorbed or infiltrated by the ground, not evapotranspired by vegetation, or not abstracted by objects on the ground surface. Runoff increases as the area of ground covered by impermeable surfaces (such as roads, parking lots, rooftops, and other paved surfaces that have limited infiltration capacity) increases. Targets could be set realistically or aspirationally, depending on the objective of the Mini Studio exercise—whether it is illustrative (showing what can be realistically done given certain parameters) or instructive (showing the methodology). 17 Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 18 Figure 3: Storm Hydrograph Showing the Difference in Peak Runoff between an Urbanized Area and a Pre-development or Greenfield Site Post-development hydrograph Runoff Pre-development Peak runoff from hydrograph a developed site Current stormwater generation and urban flood risks In an urban environment, stormwater runoff is collected via a drainage network, from small collector drains (typically called “tertiary drains”) to larger drains (“secondary or primary drains”). All the water drained from cities ends up either in large open water bodies, such as rivers or seas, or in closed water bodies, such as lakes or reservoirs. Factors that influence urban flood risk include the capacity of a city’s stormwater drainage network, land use patterns, and geophysical characteristics of the stormwater catchment. Peak runoff from pre-development site As figure 3 illustrates, an effective stormwater management strategy helps to reduce the peak volume (by reducing the runoff generated on site) and delay the sudden influx of stormwater into the drainage system (by allowing water to move gradually across the catchment). Community- and nature-based solutions are essentially small-scale, decentralized interventions that contribute to this strategy by collecting stormwater for storage and reuse, or increasing surface permeability for enhanced infiltration capacity. Time Time to Peak Source: Public Utilities Board, Singapore 2013. 19 Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 20 4.3 Developing a List of Community- and Nature-Based Measures Researching the types of traditional and community- and nature-based measures that could be Figure 4: Diagram Describing Varying Infiltration Rates Based on Different Surface Types applicable for the site, and how these approaches could be integrated and applied not only as urban flood resilience solutions, but also to enhance the quality and value of the site is a key element of the Mini Studio. Measures and approaches for urban resilience to be explored include the following. Existing stormwater management measures These may be noted by examining the existing conditions of the site, and noting down information such as the locations of drains and their systems (i.e., combined sewer overflow systems 2 or separate drainage systems), their current function (i.e., at full capacity or at reduced capacity due to being clogged with trash, etc.), the topography and direction of flows, conditions of urban development, population density, and the use of community green spaces and waterfront areas, 0 mm/hr 7 mm/hr home gardens, and rooftops, among other features. 22 mm/hr 102 mm/hr 144 mm/hr Surface coverage and infiltration It is critical to understand the limits and opportunities of both engineered and community- and 215 mm/hr more than nature-based solutions for stormwater management. Large-scale engineered solutions typically 200 mm/hr play a central role in managing a substantial amount of stormwater on a larger scale; examples include tanks and underground cisterns serving multiple developments. Community- and nature- Asphalt Bare ground Lawn Shrub Evergreen Farmland Deciduous forest tree forest based solutions, on the other hand, are flexible in their size, inexpensive to install, and serve as localized measures to supplement the absorptive capacity within the catchment. As figure 4 Source: Figure created by LRwS based on Iida et al. (2015). Note: The figures for infiltration capacity are applicable in Tokyo’s case only, where the research paper has describes, infiltration capacity greatly depends on the type of surface coverage—the capacity investigated rainwater permeability. Infiltration capacity depends heavily on a site’s geological condition. significantly increases as vegetation becomes denser—although soil type and permeability also play mm/hr = millimeters per hour. an important role. 2 Both rainwater and wastewater are conveyed and treated in a single channel. When heavy rainfall exceeds the capacity of wastewater treatment facilities, mixed sewer and stormwater overflows into rivers and the sea without proper treatment, with a significant impact on the environment. 21 Figure 5: Examples of Community- and Nature-Based Solutions Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 22 Bioswales Infiltration Rate: Examples of Community- and 140 mm/hr Nature-Based Solutions Key features: Conveyance / Detention / Filtration / Infiltration Rain Gardens Green Streets Infiltration Rate: Infiltration Rate: 140 mm/hr 140 mm/hr Key features: Key features: Detention / Retention / Filtration / Detention / Filtration / Infiltration In principle, converting impermeable hardscape areas into pervious green spaces would reduce the Infiltration amount of stormwater that eventually ends up as runoff, primarily by increasing absorption, plant Agriculture Fields Rainwater Harvesting Systems uptake, and abstraction through ground vegetation. However, this could be a challenge in rapidly Infiltration Rate: Techniques for collecting rainwater for water reuse growing cities or densely populated urban neighborhoods where there is limited physical space and 200 mm/hr No infiltration; volume stored depends on size of opportunity to convert land into parks and open spaces. The question is, therefore, how to increase equipment Key features: Key features: the softscape (infiltration capacity) within the current matrix of urban land uses and assets. Detention / Filtration / Infiltration Retention / Filtration / Water reuse Innovative stormwater management solutions Permeable Pavers Green Roofs Infiltration Rate: Infiltration Rate: 60 mm/hr Drawing upon local and international examples and inspirations, it is possible to develop a list of 100 mm/hr when the soil depth is 20[cm]. If the depth innovative urban flood management measures that integrate various types of approaches such as is doubled, the capacity is doubled. Key features: Infiltration Key features: community- and nature-based solutions. How do these measures bring additional value to a site Detention / Filtration (besides improving its stormwater management capacity)? For example, do they provide additional Downspout Planters Blue Roofs public space or points of visual interest? Figure 5 illustrates some community- and nature-based Infiltration Rate: Infiltration Rate: solutions that feature flexibility in their design, multifunctional use of space, and capacity for 100 mm/hr 200 mm/hr stormwater management. when the soil depth is 40[cm]. If the depth when the media depth is 20[cm]. is doubled, the capacity is doubled. Key features: Key features: Detention / Filtration Detention / Filtration Rainwater Tanks / Cisterns Detention / Retention Ponds No infiltration; volume stored Infiltration Rate: depends on size of equipment. depending on the size of ponds. Key features: Key features: Retention / Water reuse Retention / Detention / Filtration Source: Hironori Hayashi (detention/retention pond); Tomoki Takebayashi (for others). Note: Also, refer to the following technical guidelines and visuals on community- and nature-based projects across the world cited in Chapter 7: Public Utilities Board, Singapore’s National Water Agency n.d.; EPA n.d.; and Melbourne Water n.d. cm = centimeter; mm/hr = millimeters per hour. 23 Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 24 Figure 6: Concept Diagram of the Multifunctional Aspects of a Community- and Nature-Based Approach Storage infiltration Additional Values of Community- and Nature-Based Solutions Rainwater Evaporation storage Community- and nature-based solutions can generate additional advantages3 besides urban flood and/or disaster risk management. As illustrated in Figure 6, new values are created as outcomes of retrofitting sites with greenery, waterscapes, and devices to harvest rainwater. These include: Rainwater Rain garden utilization Rain garden • Providing communal and recreational spaces • Enhancing the site’s biodiversity • Enhancing the site's micro-climate (air quality improvement, heat island mitigation, etc.) Infiltration • Increasing property value in the surrounding area Infiltration inlet Infiltration • Generating savings in water consumption Sewerage • Raising community awareness of urban flood risks pipe Wastewater pipe To the treatment plant or to the river in the event The emphasis of the design proposal should be on not only increasing stormwater management of a flood capacity but also highlighting the additional benefits generated from the design scheme. Source: LRwS. Note: A diagram illustrating nature-based solutions for stormwater management integrated with typical municipal drainage and sewerage systems in an urban context. Multi-functional water-sensitive urban design solutions, such as rain gardens or green roofs, improve the management of runoff from urban areas while providing social, ecological, and economic co-benefits for the community. The design exercise is intended to be a creative activity that allows participants to explore the integration of innovative community- and nature-based solutions into an urban setting and describe the many values added. 3 Furthermore, refer to Browder et al. (2019) and World Bank (2020) for the additional benefits generated through implementing community- and nature-based solutions across the world. 25 Photograph 5: Mini Studio Activities, including Site Excursions, Design Exploration, and a Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 26 Pin-Up Session for Sharing Design Outcomes 4.4 Designing Innovative Solutions for Urban Flood Resilience Based on an understanding of the site context, resilience targets, and innovative ways in which stormwater management could be enhanced in cities, the most important—and exciting—part of a Mini Studio is developing a site-specific design proposal for flood resilience. Design proposals are often developed in teams, and are based on exercises that include the following elements: • Field exercise. A walk-through of the study site and surrounding area to observe and explore challenges and opportunities for urban flood resilience using the five senses. • Design and calculation. Contextualizing and visualizing proposed solutions, and estimating their effects on progress toward a specific flood management target, additional benefits, etc. • Pin-up, sharing, and reflections. Presentation of proposals, learning from others’ approaches and ideas, and reflecting on the key takeaways from the exercise that could be applied to ongoing or planned urban flood resilience projects. Figure 7, in the next pages, illustrates the steps for a typical design and calculation exercise that can be conducted for a study site, as part of a Mini Studio to explore innovative community- and nature-based flood resilience solutions. Source: World Bank GFDRR. 27 Figure 7: Steps for Typical Design and Calculation Exercise to Explore Innovative Community- and Nature-Based Flood Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 28 Resilience Solutions within a Study Area Original Site Proposed New Flood-Resilient Design Relying on potable water for Plants irrigated using collected water. maintaining greenery Evaporation has increased thanks to more vegetation Large amount of stormwater immediately discharged to drainage pipes Increased infiltration rate due to enhanced permeability Separation of landscape and hydrology; no scheme of stormwater collection, Stormwater collected in reuse, or detention water bodies Little amount of evaporation Limited amount of stormwater infiltration Aquatic plants and substrate act as cleansing agents for collected water, while beautifying the environment. Aesthetic and recreational values have increased while reducing the runoff volume from the site. STEP 1: Determine the original runoff generated on site Original surface type STEP 2: Propose new flood-resilient design for the site using Original surface area community- and nature-based tools • Calculate the volume of runoff generated on site. • Explore the study area and incorporate community- and nature-based New surface type • For the purpose of the exercise, teams will be provided with simplified Rainfall intensity (including community- figures for rainfall design parameters to use for the study area, as well (e.g. 100 mm/hr) tools, such as those described in figure 5, where appropriate. and nature-based tools) as simplified parameters of the site to calculate the runoff generated • Using the Excel sheet, teams can explore the effect of converting Rainfall duration New surface area on site such as surface type and area. (e.g. 0.5 hr) surface type to see how it influences the stormwater runoff. • Excel sheet is provided to facilitate the calculation. • Through this process, the team can calculate the new runoff generated Return period on site with the proposed interventions. (e.g. 1-in-10-year rain) Source: Modified based on information from Public Utilities Board, Singapore’s National Water Agency 2018. Note: LRWS provides a methodology and template sheet for similar workshops. More information is available at https://amamizushakai.wixsite.com/lrws/rainwater-coordinator-training-prog. STEP 3: Compare the runoff in the original versus the new scenario A calculation spreadsheet is provided for the participants to quantify the impact of their design interventions. Mini • Compare the original with proposed intervention stormwater runoff. Studio organizers could fill in the spreadsheet with existing parameters ahead of the activity, so that participants can • Teams can see the impact of the community- and nature-based tools in reducing runoff as well as lessons on focus on designing the new scenario during the exercise. effectiveness and trade-offs, etc. The methodology can be simple or detailed, depending on the needs of the participants. 29 Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 30 Photograph 6: Educational Events Advocating the Importance of Rainwater Management (top); Rainwater Runoff Reduction Ratio, before and after the Implementation of Community- and 4.5 What Comes after the Mini Studio Nature-Based Solutions (bottom) The Mini Studio exercise can be a catalytic first step for cities and communities in their efforts to develop water-sensitive, flood-resilient neighborhoods. Since a range of actions and outputs can be informed by this interactive exercise, it is important to consider its key objectives. For example, LRwS conducted a participatory Mini Studio as part of a community- and nature-based flood- resilient neighborhood design process in close collaboration with local stakeholders in the Hii River basin (Fukuoka City), which informed the following actions and outputs: • Development of a water-sensitive community vision . Based on an extensive community engagement and consultation process, including participatory Mini Studio exercises, the River Management Policy and Plan reflected citizens’ urgent need to boost urban flood resilience while maintaining and improving the river’s environmental and community functions and benefits. • Innovative design and implementation of flood management infrastructure. Hii River restoration work included various environmentally sensitive river stabilization and reinforcement methods. For example, downstream, along the tidal basins, various environmental conservation efforts were implemented. Sandy beaches were cleaned and conserved by citizens and school children, and turned into environmental education sites through activities such as clam monitoring. A part of the river surrounded by residential areas and schools was restored to enhance accessibility and recreational spaces, and the installation of rainwater harvesting systems in households was promoted. A wide range of locally suitable options were identified based on the creative thinking generated through the Mini Studio exercise. • Community mobilization and awareness raising. The Mini Studio also inspired new ways of visualizing and communicating the challenges of stormwater management and urban flood resilience and the importance of educating and engaging diverse stakeholders. Educational programs for local children, focused on community- and nature-based solutions to urban floods, were developed (photograph 6, top) as well as visual communication tools, including before- Before intervention After introducing permeable paving to sidewalks, and after comparisons (photograph 6, bottom), posters, and websites. These efforts led to the greenery to the surrounding neighborhood participatory monitoring and evaluation of interventions that included the maintenance of local Source: LRwS. streams and community parks. Note: Multigenerational interactions are essential for participatory planning. • Scaling. The innovative water-sensitive planning, design, implementation, and awareness raising conducted for the Hii River was scaled to other river basin communities such as the Zenpukuji River basin in Suginami Ward, Tokyo. 31 Photograph 7: Group Design Exploration Process from the Sumida Ward Case Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 32 5. How to Prepare and Implement a Mini Studio This chapter describes the detailed steps to prepare and implement a Mini Studio for Water- Sensitive Urban Design. Steps involved in preparation (Step 0) and implementation (Steps 1–5) are elaborated in the following subsections. Preparation stage: STEP 0: Preparing for the Mini Studio Implementation stage: STEP 1: Basic Overview of the Mini Studio Exercise STEP 2: Get into Teams and Explore the Neighborhood STEP 3: Explore the Design Site STEP 4: Group Work—Develop a Proposal for a Flood-Resilient Neighborhood STEP 5: Pin-Up Presentations and Reflection Source: World Bank GFDRR. Note: One of the distinct advantages of a Mini Studio is the synergy created among experts with different backgrounds and skills. 33 Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 34 STEP 0: Preparing for the Mini Studio 2: Creating a team A B C D 1: Agenda and program setting In the early stages of planning, it is advantageous to engage local community members, nonprofit A B C D organizations, civil society groups, and technical experts and invite them to be part of the organizing team. First, the most essential step is to set the Mini Studio’s agenda based on participants’ learning objectives. This requires understanding participants’ backgrounds, origins, and motivations for attending the Mini Studio. Based on the agenda, the overall program should be designed to 3: Selecting the site, and planning excursion routes maximize learning opportunities for participants within the limitations of time, venue, cost, and A B C D other logistics. The process of selecting the design site (size, type, and number) should relate to the defined agenda Figure 8: Sample Schedule of a Mini Studio in Sumida Ward, Tokyo as well as the number of participants and allocated time for the Mini Studio. It is advisable to make an excursion to the site to help participants understand the innovative stormwater management A B C D measures applied locally. 5. Panel on Opportunities 4: Customizing a menu of stormwater management solutions 1. 2. 3. 4. for Overview of Neighborhood Design and Pin-Ups and Implementation Mini Studio Excursion Calculation Feedback of Green Some of the basic toolkits for community- and nature-based solutions are listed in figure 5. Activities 4 hours Session 30 min Infrastructure These must be reviewed and updated to match the site’s local conditions and hydrogeologic 1 hour 1 hour 30 min and Nature- characteristics. This process will also require adjusting the stormwater runoff volume based on Based Solutions local rainfall, vegetation, soil media, and other surface characteristics. In addition, the stormwater 1 hour management target and design rainfall intensity should be set based on local rainfall characteristics A B C D or runoff management, and the planning criteria determined by the local government. Source: World Bank GFDRR. 5: Assigning design facilitators Local design facilitators who are enthusiastic about the topic will play an essential role in guiding the design discussion. These facilitators can come from a range of backgrounds and expertise, and include, for example, landscape architects, urban designers, engineers, and researchers in a related field. They may also be local community members and professionals with nontechnical, nondesign backgrounds. Local design facilitators, who are familiar with technical and design aspects, play an essential role to guide the design discussion. These facilitators should come from a 35 range of professional backgrounds, such as landscape architects, urban designers, Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 36 and researchers in related field. 6: Grouping participants Forming small teams of four to six participants each is ideal to ensure that each member has ample opportunities to contribute. Design facilitators and local guides (if any, and other supporting members) should also join each group, as their diverse perspectives, backgrounds, and expertise promise to enhance the Mini Studio exercise. Organizers should strive to bring together participants STEP 1: Basic Overview of the Mini Studio Exercise of different ages, genders, and abilities into the teams. To ensure participation, ways to address special needs (of, for example, people with disabilities) should be explored. On the first day of the Mini Studio exercise, the following points need to be concisely conveyed to A B C D all participants: 7: Preparing tools and materials for the studio exercise • What is a Mini Studio? • An overview of the Mini Studio process: • Briefing on the activities and time allocated in each step. Tools Must Have: • Introduction of teams. Thick markers (more than five colors, including green, blue, and • Briefing on the excursion, including the design site, route, and points of interest. black), sticky notes (to scribble ideas, key phrases), ruler (scale-bar), tape, and tracing paper. Good to Have: Photograph 8: Main tools for Photograph 9: Briefing Session at a Mini Studio in Pin-up boards, pins, and voting stickers (for competitions); the studio exercise Bogor, Indonesia material for model making (e.g., dried plants, colored paper, etc.). Maps/ Must Have: Images Printed out A1- or A0-size high-resolution color aerial images of the site. Good to Have: A3 map with an aerial image of the site (to be distributed during the site excursion). Reference photos of the site and of potential stormwater management solutions. Other Must Have: Stormwater calculation sheets in Excel format on a laptop or tablet. Source: Kenya Endo. Source: Kenya Endo. Note: Overall steps of each activity are explained To carry out the exercise quickly, existing stormwater runoff clearly, with objectives and expected outcomes, at the and infiltration capacity should be precalculated. beginning of a Mini Studio. 37 Photograph 10: Local Experts and Facilitators Lead the Groups’ Knowledge Sharing during the Excursion Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 38 STEP 2: Get into Teams and Explore the Neighborhood The site excursion is always the most refreshing part of the Mini Studio. Exploring the neighborhood allows participants to get an understanding of the broader site context before diving into context- specific design work. Forming a balanced team of experts (with expertise in various fields and across technical and nontechnical bodies of knowledge) of a manageable size is a critical step in the process. Likewise, time management is another important aspect that should be carefully planned and monitored during the visit. For example, the time required to translate information for an international group, or extra time required for transportation, question-and-answer sessions, and bad weather conditions should be accounted for. Participants should be told beforehand to wear walking shoes and carry a water bottle. Source: World Bank GFDRR. Note: Handouts of maps and tool kits help participants follow the design exercise. 39 Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 40 Photograph 11: Important Observations during Site Excursion: Paving Materials, Ratio of Hardscape to Softscape, Topography (low and high points), and Drainage Systems STEP 3: Explore the Design Site What to look for When exploring the site, facilitators should highlight and explain key learning points to participants related to the drainage system, topography, and surface coverage. Start discussing design vision on site Before leaving the site, a quick session to touch base with the participants will help identify issues and the potential approach for design interventions. The key is to guide participants to think outside the box and avoid the early censorship of ideas. They should be advised to not be constrained by technical practicality or financial feasibility, but to start with big ideas first, depending on the design studio goals. Source: Kenya Endo. Note: Drainage systems include waterways, outlets, and culverts. 41 Photograph 12: Facilitators Guiding and Assisting the Discussion, Building Group Consensus, and Finishing Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 42 the Exercise on Time STEP 4: Group Work—Develop a Proposal for a Flood-Resilient Neighborhood Vision and strategies First, it is critical to develop an overarching vision statement (short and concise), addressing local issues and challenges. Then, two to three site-specific strategies should be established to advance the vision. Both the vision and strategies will define the directions of spatial design, namely, surface coverage, people’s activities, and the community- and nature-based tools to be implemented. Calculation results Participants are required to fill in the Excel sheet to calculate the stormwater runoff for both the existing as well as postdesign conditions. Main inputs will be the approximate area (typically in square meters) of each surface type, which should be obtained by measuring the sketched plan using a ruler and scale bar. Supporting visuals Key words on sticky notes, concept diagrams, and small vignettes of ideas will help convey the intent of the design effectively during pin-up. Thick markers are suitable for this purpose. Place the tracing paper above the aerial image to sketch over the plan. Sectional drawings will also help explain the composition of different landscape elements, people’s experiences, and their functions. It is important to include a person, car, or tree in the sketch to represent the scale. Considering time limitations, the graphics do not need to be of high quality. Source: World Bank GFDRR. 43 Photograph 13: Participants Pitching Their Key Ideas through Sketched Diagrams, Plans, and Sections at a Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 44 Mini Studio in Bogor, Indonesia STEP 5: Pin-Up Presentations and Reflection It is highly recommended that a nominated presenter concisely wrap up each pin-up presentation with a summary of key outcomes. The suggested time is a maximum of five minutes, followed by a two- to three-minute question-and-answer session. While standing in front of the panels and drawings, the presenter should mention the process of design development: (i) site analysis, (ii) the challenge that needs to be addressed, (iii) the vision statement, and (iv) strategies and specific design interventions through sketches. These drawings should be in relation to the surrounding context, in proper scale, and offer some sense of the spatial experience. In addition, stormwater runoff calculation results before and after the design should be shared to quantify the effectiveness of the proposed solutions. After the pin-up session, it is important to allot time for the various teams to interact and ask questions of one another. Source: Kenya Endo. Note: It is advisable to pin up all materials, even incomplete scribbles, without being shy. 45 Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 46 6. Experiences and Lessons from Past Mini Studios Context In this chapter, we share lessons learned from Mini Studios convened in Tokyo, Japan, and Bogor, Sumida Ward is located on low-lying land near the Sumida River, which exposes its dense Indonesia, to help inform the design of future Mini Studios for Water-Sensitive Urban Design. concentration of houses and office buildings to high flood risks. During the 1980s, urban flooding The agenda, participants, and context will greatly influence the preparation and implementation occurred frequently in the ward during heavy rains, as low infiltration and insufficient drainage stages of a Mini Studio. These examples provide a general framework to be tailored to individual capacity left streets and buildings inundated. Impermeable surfaces cover over 70 percent of circumstances. Sumida Ward, compared with 50 percent on average across Tokyo’s 23 wards (Next Wisdom Foundation 2015). 6.1 Technical Deep-Dive Session in Sumida Ward, Tokyo Additionally, enhancing underground infiltration capacity was difficult, given that most of Sumida Ward’s land was below sea level. With limited space to develop new, large-scale stormwater Japan Overview detention facilities aboveground, the ward relied heavily on publicly financed high-cost gray infrastructure, such as underground drainage channels and detention facilities and pumps. The Mini Studio on community- and nature-based solutions for IUFRM was held as part of a Technical Deep-Dive (TDD) session at the World Bank’s Tokyo Development Learning Center However, increasing flood risks and other developments created an urgent need for further measures (TDLC). This TDD session was the second of a learning series bringing together practitioners and against surface water flooding and the resulting damages. In response, Sumida Ward began a government officials from around the world to exchange notes with one another and learn from movement in 1982 to harvest, store, and utilize rainwater through public, private, and community international and Japanese experiences with IUFRM measures. Representatives of nine World efforts, based on the concept of an “urban dam.” The collaboration enabled the installation of Bank client countries4 joined the Mini Studio exercise, including national and local officials from rainwater storage facilities in residential areas and public and private facilities distributed widely the planning, infrastructure, and management departments. Five investigation sites were chosen throughout the ward, providing a decentralized approach to surface flood management. from Sumida Ward, in the eastern part of Tokyo, where small-scale innovative tools for managing urban floods have been implemented over the years. After a briefing by local experts and a site The Mini Studio’s site excursions included a look at community-based, small-scale rainwater excursion with community members,5 participants explored ideas on further enhancing stormwater harvesting systems for households called Rojisons, and both public and private development management capacity in this dense urban neighborhood. projects that are integrated with large detention facilities, such as the Sumida Hokusai Museum, Tokyo Skytree Town, and Sumo Wrestling Arena (for more details on context, refer to World Bank Date: April 23, 2019; 10:30 a.m. to 5 p.m. [2020]). Venue: World Bank TDLC office (approximately 30 minutes’ travel time from various investigation sites in Sumida Ward). Participants: 60 representatives from 9 countries, forming 9 groups. Facilitators: 18, including local experts, community members, and World Bank staff. 4 These countries are (alphabetically), Albania, Angola, Jordan, Lao PDR, Myanmar, Panama, Paraguay, Turkey, and Vietnam. 5 There was support from the local nonprofit organization, People for Rainwater (http://www.skywater.jp/ aboutus#shiminnokai). Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 48 Photograph 14: Sumida Ward (red dashed line depicts the aerial view) in the Eastern Part of Tokyo Metropolitan Area Mukojima Neighborhood Tokyo Skytree Design exploration Sumida Ward The Mini Studio’s design exploration is flexible and scalable enough to be exercised in any urban site, from small dense neighborhoods to linear streetscapes. In the case of Sumida Ward, the organizing team had selected five different types of sites: an urban plaza in front of the train station, a streetscape, a riverfront corridor, a plot within a dense neighborhood, and a public school. All the sites had little infiltration capacity due to impermeable paving and buildings. Participants were challenged to increase the infiltration capacity, by referring to the innovative tools listed in figure 5, with the target of managing a one-hour-long, 75 mm/hr rainfall. Sumida River The following pages illustrate the outcomes of the exercise. The selected works strongly present a compelling vision with the effective use of graphics, such as diagrams, plans, and sections. A runoff Arakawa reduction ratio of more than 100 percent means that the site not only improved its spatial quality River based on the vision, but also increased its capacity to hold and infiltrate rainwater significantly. Source: Google Earth, Imagery©2020 TerraMetrics, Map data©2020 (aerial view, left); Kenya Endo (Rojison and small- scale rainwater harvesting tank in the community, right top); Johnson 2016 (Tokyo Skytree Town, right bottom). Note: Sumida Ward has a population of approximately 250,000 people and a total area of 13.77 km2. The area is considered a part of the capital’s dense shitamachi, or old town, and the great Sumida and Arakawa Rivers form part of its boundaries. The Mukojima neighborhood, which uses small-scale community-based rainwater harvesting facilities, Tokyo Bay was one of the communities investigated (right top). The area is home to the landmark Tokyo Skytree (right bottom), the 500m world’s tallest self-supporting tower. 49 Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 50 Site Base Design vision: Design rainfall intensity: Typical urban block in Mukojima Site area: 594 m2 Small is beautiful 75 mm/hr neighborhood Building area: 501 m2 Softscape area: 0 m2 Calculation result: Country team and design facilitator: Impermeable paving: 93 m2 Volume of rainwater produced: 102.0 m3 Paraguay, Sayaka Yoda [before] Runoff reduction ratio: 0.0% [after] Runoff reduction ratio: 235.0% Figure 9: Extension of site boundary to incorporate Photograph 15: Urban Block in Mukojima Neighborhood small yet effective design interventions Key concept is to reduce runoff significantly: sunken sports court for rainwater detention purposes 20m (→multipurpose), rainwater harvesting tanks for each household, increase in permeable surfaces, and green roofs to enhance infiltration capacity. 15m Source: Google Earth, Imagery©2020 Digital Earth Technology; Maxar Technologies, The Geoinformation Group, Map Source: Paraguay team. data©2020 (aerial view, left); Google Streetview ©2020 Google (eye-level view, right). Note: The Paraguay team incorporated other potential elements into Note: The urban block is composed of four single detached buildings and one parking lot. There is no softscape coverage. The their design interventions, such as roads, an adjacent parking lot, and design focus was on inserting various nature-based solutions into hardscapes and rooftops of existing buildings. flat-roofed houses for green-roof installations. 51 Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 52 Site Base Design vision: Design rainfall intensity: Daiichi Terajima Elementary School in Site area: 5,942 m2 Sponge School—Water for Living and Inclusive Community 75 mm/hr Mukojima neighborhood Building area: 2,024 m2 Softscape area: 117 m2 Calculation result: Country team and design facilitator: Impermeable paving: 3,625 m2 Volume of rainwater produced: 445.6 m3 Turkey, Jun Hashimoto Others: 176 m2 [before] Runoff reduction ratio: 2.6% [after] Runoff reduction ratio: 103.7% Photograph 16: Daiichi Terajima Elementary School, a Public Figure 10: Sponge School: A Community Hub for Rainwater Education School in a Dense Residential Neighborhood and Experiments 20m 15m 15m Source: Google Earth, Imagery©2020 Digital Earth Technology; Maxar Technologies, The Geoinformation Group, Map Source: Turkey team. data©2020 (aerial view, left); Daiichi Terajima Elementary School 2020 (eye-level view, right). Note: Illustration shows the concept of (i) training the next generation Note: Most of the exterior spaces in the site are covered by impermeable paving, artificial grasses, and bare ground. in how rainwater management can be integrated in farming activities, (ii) enhancing infiltration capacity by upgrading existing green zones, and (iii) appreciating the value of rainwater by reusing it. 53 Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 54 Site Base Design vision: Design rainfall intensity: Oshinari Park and Kitajukken-gawa River Site area: 5,895 m2 Naturalized Tokyo Canal for Urban Creatures 75 mm/hr in Tokyo Skytree district Building area: 1,024 m2 Softscape area: 357 m2 Calculation result: Country team and design facilitator: Impermeable paving: 3,732 m2 Volume of rainwater produced: 402.5 m3 Lao PDR, Kiyohito Tamotsu Others: 777 m2 [before] Runoff reduction ratio: 5.1% [after] Runoff reduction ratio: 100.0% Photograph 17: Oshinari Park and Boardwalk along the River Attracts Visitors to Tokyo Skytree Town Figure 11: Breakthrough Ideas for Naturalized Tokyo Canal 20m Source: Google Earth, Imagery©2020 Digital Earth Technology; Maxar Technologies, The Geoinformation Group, Map Source: Lao PDR team. data©2020 (aerial view, left); Kenya Endo (waterfront park and boardwalk along the Kitajukken-gawa River, right). Note: Breakthrough ideas include introducing (i) floating wetlands in the river for nutrient uptake (+aeration) for cleansing Note: A fountain-like aeration facility and accessible promenades enhance the attractiveness of the riverfront spaces. purposes, (ii) flowering and drooping plants to soften the building/river wall facades, (iii) edible vegetation to attract birds and butterflies, and (iv) movable planter boxes and benches to enhance the outdoor comfort of the site. 55 Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 56 Photograph 18: Snapshots of Group Design Discussions and Sketches during the Mini Studio in Bogor, Indonesia 6.2 Integrating Nature-Based and Green Solutions for Urban Flood Risk Management, Design Charrette, Bogor, Indonesia Overview As part of the continuous development of a conceptual framework for a proposed national urban flood resilience program in Indonesia, the Mini Studio served to facilitate stakeholder engagement. It was conducted in Bogor with central government agencies and local government officials from the cities of Ambon, Bima, Manado, Padang, and Pontianak. An investigation site was set up at the Aston Hotel and Resort in Bogor, with a focus on the hotel parking lot and outdoor spaces surrounding the hotel buildings. The Mini Studio briefing included renowned cases of community- and nature-based solutions across the world, followed by a short site excursion to understand the local context. Date: July 11, 2019, 2 p.m. to 6 p.m. Venue: Aston Bogor Hotel and Resort, seminar room. Participants: 20 representatives from 5 selected cities in Indonesia, forming 3 groups. Facilitators: 3 (1 technical expert per group). Context Bogor, Indonesia, is a city approximately 60 kilometers (km) south of Jakarta on Java Island, set against the volcanic backdrop of Mount Salak. Dubbed the “Rain City,” Bogor is more humid and rainier than many other areas of West Java. The average relative humidity is 70 percent, and the average annual precipitation is about 4,086 mm (Climate-Data.org n.d.). In this geographical context, flooding and landslides frequently affect people’s lives and assets. The most recent flood occurred in early January 2020 and killed 16 people in the city (The Jakarta Post 2020). Source: World Bank GFDRR. Photograph 19: Aston Bogor Hotel and Resort (left); Cisadane River Tributary (right top); Resort Parking Lot (right bottom) Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 58 Design exploration The focal site was a large parking lot approximately 18,500 m2 in size (more than three times larger than that studied during the Mini Studio in Sumida Ward), with a pervious surface consisting of 25 percent of the total area. This allowed participants to reimagine the site from various perspectives. Hotel Car Since all three groups worked with one given site, it was interesting to see the stark differences in Parking Lot Small Stream the design outcomes based on their respective visions. (tributary of Cisadane River) Innovative tools for design interventions remained the same as in figure 5, with the target of managing a one-hour-long, 160 mm/hour rainfall, following the local climatic conditions. Aston Bogor Hotel Lobby The design process successfully facilitated cross-agency interactions focused on site analysis, spatial designs, and estimates of stormwater management capacity. The process of developing schematic sketches and guiding principles helped participants to move toward actual implementation of these measures in their respective cities—with detailed considerations of technical, financing, legal, and operation and maintenance issues. Source: Google Earth, Imagery©2020 CNES/Airbus; Maxar Technologies, Map data©2020 (aerial view, left); Kenya Endo (eye-level view of small stream and hotel parking lot, right). Note: The resort is located 5 km from the center of Bogor City. The Cisadane River tributary running through the hotel grounds collects rainwater from the surrounding neighborhood. 50m 59 Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 60 Site Base Design vision: Design rainfall intensity: Aston Bogor Hotel and Resort, Site area: 18,500 m2 Memorable and Water-Friendly Hotel 160 mm/hr parking lot and surrounding Building area: 2,400 m2 Softscape area: 4,500 m2 Calculation result: Team and design facilitator: Impermeable paving: 11,600 m2 Volume of rainwater produced: 2,960 m3 Pontianak City, Kenya Endo [before] Runoff reduction ratio: 16% [after] Runoff reduction ratio: 58% Photograph 20: Aston Bogor Hotel and Resort Parking Figure 12: Zoning Diagram Illustrating Types of Surface Lot and Surroundings Coverage Figure 13: Illustrations of a Water-Friendly Hotel 1000m Source: Google Earth, Imagery©2020 CNES/Airbus; Maxar Source: Pontianak City team. Source: Pontianak City team. Technologies, Map data©2020. Note: These simple line drawings with dimensions and Note: A large portion of the parking lot was converted into a multipurpose sunken semipublic green Note: The site is mostly covered with impermeable interlocking annotations will facilitate the runoff reduction calculation field for both water detention and recreational activities. The parking facility was compactly tucked concrete pavers with some planting strips in between. The process. into a corner, to give priority to the blue-green features facing the public road. parking lot gently slopes toward the stream, implying that the rainwater runoff is effectively conveyed and discharged to the stream. 61 Mini Studios for Water-Sensitive Urban Design: A Handbook for Organizers and Facilitators 62 6.3 Tips and Recommendations for Future Mini Studios vary from place to place. As such, the target rainfall intensity and infiltration rates should be based Past Mini Studios offer many lessons for future organizers. These include the following. on the local context. It must be noted that this design exercise is heavily simplified for ease of application. The methodology does not take into account the effect of surface area on the runoff 1: Ensure that the program is tailored to the audience rate (or the runoff coefficient), the runoff rate over the rainfall duration (or the hydrograph), or the appropriate design rainfall duration. Researching local conditions, and modifying the values and Customizing the program is key to success. Among other things, it should be tailored to the number methodology accordingly, will make the design outcomes more realistic and accurate. Participants of participants and their experience levels, expectations, and available time; the accessibility of should not limit their creativity to the community- and nature-based solutions in figure 5 . field visit sites; the number, expertise, and skills of available technical and support staff; and the Facilitators should encourage new design solutions during the design exercise, by referencing local intended outcomes of the Mini Studio. The length and order of the various components of a Mini practices and participants’ past experiences. Studio should be considered carefully in light of the context and objectives. 5: Allot sufficient time for the design exercise Preliminary steps include organizing teams, preparing introductory information to share, and putting aside time to conduct design exercises. The program structure depends on the number of Allocation of time can vary depending on the time available to conduct the exercise. Participants participants and their backgrounds. might feel that the time allocated to the design exercise (which can range between one and two hours, or longer) is too short. But more time does not necessarily mean greater productivity. 2: Engage local experts as resources and design facilitators Facilitators must plan and split the time based on milestones (e.g., concept development, 10 minutes; brainstorming ideas and sketching, 10 minutes; etc.) in order to finish the exercise within A Mini Studio requires a strong team with diverse expertise; the exercise can be enhanced through the given time frame. The suggested time for the oral presentation should be a minimum of five the participation of technical/nontechnical, design/nondesign facilitators; experts in local history minutes, followed by a two- to three-minute question-and-answer session. and context (from nonprofit organizations, community groups, students, etc.); and supporting staff to handle logistics and time management. A good facilitator and knowledgeable and flexible support 6: Encourage and enable engagement of all participants members can ensure that any unforeseen circumstances are dealt with effectively. A Mini Studio provides an opportunity for all participants to tackle one common issue. Facilitators 3: Select design sites and excursion routes to maximize learning opportunities for the should create an enabling and welcoming environment so that all participants, regardless of their participants backgrounds and experiences, feel comfortable sharing their unique ideas and perspectives. Facilitators are encouraged to celebrate diverse and out-of-the-box thinking from each team It is advisable to select a few sites that have different development patterns, contexts, and densities member. to be able to compare different design approaches, as well as runoff reduction results. The site excursions should be well planned. Facilitators and coordinators should know the route beforehand 7: Share proposals with local stakeholders so that the briefing can be conducted smoothly. Involving local stakeholders in the pin-up session is beneficial to receive feedback and first-hand 4: Customize stormwater management targets, parameters, and tools to match the knowledge from people on site. Conceptual ideas discussed during the Mini Studio can potentially local context be converted to action plans with the support of a local community-based committee.6 This exercise is largely context-specific: precipitation patterns, rainfall intensity, and soil conditions 6 Refer to Yamashita et al. (2018) for more details. 63 7. References Additional Resources Browder, Greg, Suzanne Ozment, Irene Rehberger Bescos, Todd Gartner, and Glenn-Marie Lange. 2019. Integrating The following publications, developed as part of the World Bank Urban Floods Community of Practice, provide Green and Gray: Creating Next Generation Infrastructure. Washington, DC: World Bank and World Resources Institute. additional tools and knowledge on international good practices for enhancing urban resilience against floods: https://openknowledge.worldbank.org/handle/10986/31430. Bureau of Urban Development, Sumida Ward. 2018. “Sumida City Flood Hazard Map.” Jha, Abhas K., Robin Bloch, and Jessica Lamond. 2012. Cities and Flooding: A Guide to Integrated Urban Flood Risk https://www.city.sumida.lg.jp/anzen_anshin/katei_tiikinobousai/kouzui_hm1.files/2018_HM_sassi_japanese.pdf. Management for the 21st Century. Washington, DC: World Bank. Climate-Data.org. N.d. “Bogor Climate Summary”. Accessed March 31, 2020. https://openknowledge.worldbank.org/handle/10986/2241. https://en.climate-data.org/asia/indonesia/west-java/bogor-3930/. World Bank. 2017. “Flood Risk Management at River Basin Scale: The Need to Adopt a Proactive Approach (English).” Daiichi Terajima Elementary School. 2020. “School’s Eye-Level View.” http://www.sumida.ed.jp/ichiterajimasho/. Urban Floods Community of Practice (UFCOP) Knowledge Notes, World Bank, Washington, DC. http://documents. EPA (United States Environmental Protection Agency). N.d. “Urban Runoff: Low Impact Development.” worldbank.org/curated/en/876061497622506400/Flood-risk-management-at-river-basin-scale-the-need-to- https://www.epa.gov/nps/urban-runoff-low-impact-development. adopt-aproactive-approach. Gonzalez, Paul. 2016. “Flooding in China.” Photograph, July 20, 2016. Accessed March 31, 2020. World Bank. 2017. “Land Use Planning for Urban Flood Risk Management (English).” UFCOP Knowledge Notes, World https://flic.kr/p/JnDpEJ. CC BY 2.0. Bank, Washington, DC. http://documents.worldbank.org/curated/en/858461494250358652/Land-use-planning- Grenet, Karl. 2015. “Bangkok Flooding.” Photograph, March 24, 2015. Accessed March 31, 2020. for-urban-flood-risk-management. https://flic.kr/p/qPDo3J. CC BY-NC-ND 2.0. Iida, Akiko, Hiroaki Yamato, Seiji Hayashi, and Mikiko Ishikawa. 2015. “A Simulation Study of Rainwater Infiltration and Flood Prevention Effects by Urban Green Spaces in Kanda River, Tokyo.” Journal of the City Planning Institute of Japan 50 (3). https://www.jstage.jst.go.jp/article/journalcpij/50/3/50_501/_pdf. Jakarta Post, The. 2020. “West Java Declares Emergency over Floods, Landslides as Death Toll Rises.” The Jakarta Post, January 4, 2020. Accessed March 31, 2020. https://www.thejakartapost.com/news/2020/01/04/west-java- declares-emergency-over-floods-landslides-as- death-toll-rises.html. Johnson, Hans. 2016. “Tokyo Skytree Town.” Photograph, February 26, 2016. Accessed March 31, 2020. https://flic.kr/p/Gbxpfg. CC BY-ND 2.0. Melbourne Water. N.d. “Introduction to WSUD.” https://www.melbournewater.com.au/planning-and-building/ stormwater-management/introduction-wsud. Next Wisdom Foundation. 2015. “Sharing Sumida Ward Experience with the World: The Use of Rainwater.” June 22, 2015. http://nextwisdom.org/article/680/. Public Utilities Board, Singapore’s National Water Agency. 2013. Managing Urban Runoff: Drainage Handbook. Singapore: Public Utilities Board. https://www.pub.gov.sg/ Documents/managingUrbanRunoff.pdf. Public Utilities Board, Singapore’s National Water Agency. 2018. ABC Waters Design Guidelines, 4th edition. https://www.pub.gov.sg/Documents/ABC_Waters_Design_Guidelines.pdf. Public Utilities Board, Singapore’s National Water Agency. N.d. “Active, Beautiful, Clean Waters (ABC Waters) Programme.” https://www.pub.gov.sg/abcwaters. Tokyo Metropolitan Government. 2014. “Tokyo Metropolitan Basic Plan for Countermeasures against Torrential Rains (Revised).” http://www.tokyo-sougou-chisui.jp/river/gouutaisaku-houshin_1406.pdf. Wallemacq, Pascaline, Regina Below, and Denis McLean. 2018. Economic Losses, Poverty & Disasters: 1998–2017. UNISDR and CRED Report. https://reliefweb.int/sites/reliefweb.int/files/resources/61119_credeconomiclosses_0.pdf. World Bank. 2020. Learning from Japan’s Experience in Integrated Urban Flood Risk Management: A Series of Knowledge Notes. Washington, DC: World Bank. http://documents.worldbank.org/curated/en/471791582142297709/pdf/Learning- from-Japans-Experience-in- Integrated-Urban-Flood-Risk-Management-A-Series-of-Knowledge-Notes.pdf. Yamashita, Sampei, Tomoki Takebayashi, Hiroki Iyooka, and Teruki Hamada. 2018. “Decentralized Water Management and Local Community Development in the Hii River Basin.” 57th conference of JSCE Infrastructure Planning and Management presentation papers 57: 8 (CD-ROM). Labs for Rainwater Society Labs for Rainwater Society (LRwS) is a network of researchers primarily based at Kyushu University, Fukuoka City, Japan, with the agenda of promoting a decentralized, self-sufficient rainwater management system for a resilient society. The organization promotes multigenerational and communal interactions in the cycle of rainwater harvesting, storage, and reuse. Website: https://amamizushakai.wixsite.com/lrws. World Bank Tokyo DRM Hub The World Bank Tokyo Disaster Risk Management (DRM) Hub supports developing countries to mainstream DRM in national development planning and investment programs. As part of the Global Facility for Disaster Reduction and Recovery, the DRM Hub provides technical assistance grants and connects Japanese and global DRM expertise and solutions with World Bank teams and government officials. The DRM Hub was established in 2014 through the Japan–World Bank Program for Mainstreaming DRM in Developing Countries—a partnership between Japan’s Ministry of Finance and the World Bank. Urban Floods Community of Practice Urban Floods Community of Practice (UFCOP) is an umbrella program commited to sharing operational and technical experience and solutions for advancing an integrated approach to urban flood risk management, and leveraging the expertise and knowledge of different stakeholders and practice groups and across the World Bank Group. The program supports the development of an interactive space for collaboration and exchange on the subject, facilitating users’ access to information and adaptation of knowledge to local conditions, and bringing together different stakeholders to enhance collective knowledge on integrated urban flood risk management. GFDRR The Global Facility for Disaster Reduction and Recovery (GFDRR) is a global partnership that helps developing countries better understand and reduce their vulnerabilities to natural hazards and adapt to climate change. Working with over 400 local, national, regional, and international partners, GFDRR provides grant financing, technical assistance, training, and knowledge sharing activities to mainstream disaster and climate risk management in policies and strategies. Managed by the World Bank, GFDRR is supported by 36 countries and 10 international organizations. Contact World Bank Disaster Risk Management Hub, Tokyo Phone: +81-3-3597-1320 Email: drmhubtokyo@worldbank.org Website: www.worldbank.org/drmhubtokyo