Rainwater harvesting: a potential way forward
The potentiality of rainwater harvesting to address household level water scarcity as well as to enhance groundwater recharging has already been tested in the context of Bangladesh and in many other countries in the Asian and African regions. Particularly in the coastal areas of Bangladesh, indigenous knowledge and practice of catching, storing and using rainwater as an alternate source of drinking water have been evident for long. The Government of Bangladesh and its development partners have also been promoting rainwater as an alternative source of potable water in response to arsenic problem. Bangladesh receives annual average rainfall of 2150 mm which is almost three times more than the world average of 800 mm. But the potentiality of this huge rainfall remains mostly un-utilized since using rainwater for drinking and other household usages is still not socially and technologically very familiar in Bangladesh. In the CHT and in urban areas it is only a recent phenomenon although it is now widely agreed that use of rainwater will reduce the pressure on groundwater supply to a great extent which may also contribute to reduce the problem of water logging in the urban areas. It is anticipated that if utilized properly, rainwater has the potentiality of meeting many of the challenges being faced by the urban areas in relation to increase access to safe water and some other urban environmental problems. Recent initiatives in Bangladesh
Recently, the Institute of Water Modeling (IWM) in Bangladesh has conducted a pilot study for Dhaka WASA (Water and Sewerage Authority) to assess the possibility and potentiality of groundwater recharging through rainwater harvesting and concluded that if done properly, it could arrest further decline and to a great extent increase the water table in Dhaka. With support from Unicef, the University of Dhaka has done a pilot study in saline intruded coastal belt about the possibility of using rainwater as an alternative source of potable water and observed huge potentiality. Mainly to popularize rainwater harvesting and to create a pool human resources on the subject, WaterAid Bangladesh in collaboration with the Centre for Science and Environment (CSE), India has taken a systematic approach and so far conducted few number of trainings on Urban Rainwater Harvesting. This program was participated by academia, professionals like Architects, Civil Engineers, Environmental Consultants, Lawyers, Urban Planners, Government and NGO Officials from different institutions of Bangladesh. However, this is not enough to popularize rainwater in policy and practice levels.
