Research: Potential of 3R techniques to enhance fresh water availability in Bangladesh Executive Summary Dry season in Bangladesh causes water crisis In Bangladesh, due to high salinity in surface and groundwater, people are facing acute water crisis in many areas of the coastal region and hence, are looking for alternatives. To address the water crisis in this region, where rainfall is abundant, the 3R techniques (water recharge, retention and reuse) are often thought as a potential solution by experts. Several techniques of 3R can increase water storage capacity and improve water availability throughout the seasons. Some of these techniques are ancient and time-tested, others are new and innovative. How to enhance water availability through 3R options? While several 3R techniques (groundwater recharge, soil moisture storage, closed storage tanks and open surface reservoirs) have been used under different projects in Bangladesh to address water scarcity, the applications are often constrained by a number of factors, including lack of information on technologies, limited skills, lack of research and lack of awareness. Therefore, adequate research was needed to facilitate the utilization of 3R techniques and to encourage investment decisions towards effective and efficient use of the water resources. Hence, this study was carried out focusing on assessing the 3R practices (that includes rainwater harvesting) in Bangladesh, especially in rural areas of coastal region where the 3R techniques have been practiced. Mixed method of best practices, previous studies and expert knowledge The study focused on understanding the context of coastal region in relation to water supply systems, identifying main challenges in bringing 3R techniques into practices, the benefits and sustainability of such practices, and potential for scaling up of the 3R techniques in Bangladesh. During the study reports and publications on previous research and development projects carried out by organizations/researchers working in WASH sector were studied. In addition, field visits were conducted to assess the current condition of the different 3R techniques and to gather feedback from beneficiaries. The study also took support from sector professionals to identify the challenges and draft recommendations. The FIETS (Financial, Institutional, Environmental, Technological and Social) sustainability criteria approach of WASH Alliance International was used in the study in assessing the sustainability of the 3R techniques in the study areas. 1 | P a g e Successes of existing application of 3R options in coastal areas Among the available techniques of water recharge, retention and reuse, groundwater recharge is still in research phase in coastal areas where potential of Managed Aquifer Recharge (MAR) is currently being tested. Its potential for scaling up in coastal region would largely depend on its performance, and identifying the specific conditions (e.g., salinity level, catchment characteristics, depth of water table, etc.) where MAR would be beneficial. The soil moisture storage practice was found in limited areas as the soil salinity in many areas of the coastal region due to natural and man-made reasons has made agriculture difficult. However, in areas that are favorable for agriculture, storing rainwater in soil and small ponds for irrigation in dry period has shown good results and provides potential for improvement of existing farming practices. This practice would keep the soil quality favorable for agriculture in saline-prone areas and beneficial because with small low-cost farmer level interventions, less water from external source is needed, limiting infrastructure needed for irrigation. The closed tank storage technique, which is mainly rooftop rainwater harvesting system using closed tanks, is one of the most popular options for rural communities in salinity affected areas. Given the proven application this technique has good potential to be scaled up. If rainwater tank of adequate capacity can be provided to the users, this technology can fulfill the year-round demand. However, attention is needed on management of water quality and promotion of low- cost systems considering the affordability of low-income people to install the systems. The fourth technique is storing rainwater in open surface reservoirs for using in dry period for drinking/cooking purposes as well as for agriculture. These ponds or reservoirs was found as source of water in many villages where groundwater is saline or difficult to extract (hilly areas). Since the acceptance of pond water is very high for drinking/cooking purposes in absence of fresh groundwater and/or rainwater during dry season, there is scope of developing pond water based water supply systems in saline affected areas. Few individuals/organizations have started making business by selling pond water after treatment in few areas. Lack of proper management and inadequate awareness among the stakeholders were found as the main challenges. How to sustain 3R interventions in Bangladesh In Bangladesh, there is potential for scaling up of the techniques of water recharge, retention and reuse to address the challenge of water availability and to improve use of the abundant rainfall in the dry period. While some of the 3R interventions have been found very popular (e.g., closed tank storage, use of small reservoirs for farming, etc.) in many areas of the coastal region, its applicability could be enhanced through strong collaboration among government, its development partners and local communities to improve the water supply system in coastal 2 | P a g e region of Bangladesh. To make the best use of the available 3R techniques and to be sure that implementation of systems is sustainable, the following areas need to be emphasized: developing mechanism for financial sustainability, including an institutional approach, performing site specific research, awareness raising activities and local and regional capacity building on 3R. 3 | P a g e Contents Executive Summary ................................................................................................................................ 1 Contents.................................................................................................................................................. 4 List of Figures .......................................................................................................................................... 6 1. Introduction ........................................................................................................................................ 7 2. Background and Objectives.................................................................................................................. 9 2.1 What is 3R ..................................................................................................................................... 9 2.1.1 Recharge ................................................................................................................................. 9 2.1.2 Retention ................................................................................................................................ 9 2.1.3 Reuse .................................................................................................................................... 10 2.2 Application of 3R ......................................................................................................................... 10 2.3 FIETS Sustainability Criteria .......................................................................................................... 13 2.4 Study Context and Objectives ...................................................................................................... 17 3. Methodologies .................................................................................................................................. 19 3.1 Collection and review of relevant publications/reports: ............................................................... 19 3.2 Collection and analysis of rainfall data: ........................................................................................ 19 3.3 Development and finalization of assessment tools: ...................................................................... 20 3.4 Site selection for field visits: ......................................................................................................... 20 3.5 Field visits, FGD and KII ................................................................................................................ 21 3.6 Consultative workshop: ............................................................................................................... 22 4. Groundwater Recharge and Storage .................................................................................................. 24 4.1 Technologies of groundwater recharge ........................................................................................ 24 4.2 Potential and practice of groundwater recharge .......................................................................... 25 4.3 FIETS Sustainability Assessment ............................................................................................... 28 5. Soil Moisture Storage ........................................................................................................................ 29 5.1 Technologies ...............................................................................................................................