CSE has put together and submitted a report to the MoUD on “Urban Rainwater Harvesting: Case studies from different agro-climatic regions” as a part of its deliverable as a Centre for Comprehensive Capacity Building, under Jawaharlal Nehru National Urban Renewal Mission (CCBP- JnNURM) for Sustainable Water Management.
Modern water management relies heavily on cost intensive long distance transfer of water to meet the growing water demand as well as overexploitation of in-situ groundwater resources. Sustainable water management requires understanding the value of rain, and to make optimum use of rainwater at the place where it falls. With rapid urbanization and greater areas coming under roofs and concrete structures, water utilities have solely focused on augmentation and failed to combine traditional wisdom with modern engineering.
The report discusses two case studies successfully implemented from different agro-climatic regions of India - (i) low (scanty) rainfall area: Birkha Bawari (Jodhpur, Rajasthan) and (ii) very high rainfall area: Goa University. In both cases it is clearly evident that the selection of system is site and context specific. For planning and delivery of any RWH the information and data to be considered include: geological boundaries; hydraulic boundaries; inflow and outflow of waters; storage capacity; porosity; water resources available for recharge, natural recharge; water balance; depth of aquifer and tectonic boundaries that may vary from site to site.
The report with the help of case studies seeks to encourage discussion with urban local bodies or water management organisations on the potential of mainstreaming rainwater harvesting, the need for sustainable water management practices at present and discussing the way forward.