In Bangladesh, due to high salinity in surface and groundwater, people are facing acute water crisis in many areas of the coastal region, especially during the dry season from December to May. Rain water harvesting options such as groundwater recharge, soil moisture storage, closed storage tanks and open surface reservoirs offer opportunities to enhance the availability of fresh water in the coastal region. This water being harvested can be used to improve agricultural production or for drinking/kitchen water. The latter is especially relevant for communities currently depending on arsenic polluted ground water resources. Some of rain water harvesting options are ancient and time-tested techniques – like Motka pots, others are new and innovative – like the managed aquifer recharge (MAR).
RAIN (a brand of Aidenvironment), together with ITN-BUET Dhaka, has published the final report of an in-country study to identify main challenges in the implementation of these rain water harvesting practices, the benefits of such practices and the potential for scaling up of successful practises. The recommendations provided in the report will be used in the inception phase of an upcoming 5-year WASH program, implemented by the Dutch SDG consortium, in which RAIN is a partner. During the study, previous publications 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 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 techniques already implemented in the coastal areas.
Among the available techniques of water recharge, retention and reuse, groundwater recharge is still in the research phase. In coastal areas, the potential of Managed Aquifer Recharge (MAR) is currently being tested. Its potential for scaling up would largely depend on its performance, and identification of the specific optimal conditions (such as salinity level, catchment characteristics, depth of water table, etc.). Closed tank storage 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 tanks of adequate capacity can be provided to the users, this technology can fulfil 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 purchase the systems. Storing rainwater in open surface reservoirs for using in dry period for drinking/cooking purposes as well as for agriculture is another option. These ponds are already a major source of water in many villages where groundwater is saline. Since the acceptance of use of pond water for drinking/cooking purposes is very high, especially in absence of fresh groundwater, there is an opportunity of developing pond based water supply systems. Lack of proper management and inadequate awareness among the stakeholders were found as the main challenges for pond management. Entrepreneurs in the region have started businesses selling pond water after treatment.
While some of the techniques 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 region of Bangladesh. To make the best use of the available 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 how to make use of available water resources sustainable.
For more information, please contact Arnoud Keizer.