Floodplains and water bodies like ponds, canals in Dhaka city are very crucial because they serve as the source of surface water by storing rainwater, and at the same time, help recharge of underground aquifers through percolation, planners and engineers said at a discussion yesterday.
“But wetlands are being ruthlessly destroyed in violation of the capital's master plan to make way for businesses,” said Dr Ishrat Islam, an urban planning professor at the Bangladesh University of Engineering and Technology (Buet).
The master plan is breached to serve individuals' business interests, said Dr Md Akter Mahmud, general secretary of the Bangladesh Institute of Planners.
The Bangla daily Prothom Alo and WaterAid jointly organised the discussion on the conservation and use of rainwater in the cities at the newspaper's office in the capital.
Dhaka Water Supply and Sewerage Authority (Wasa) currently generates only percent of 230 crore litres of water it needs to feed the city dwellers daily from surface water, said the agency's managing director, Taqsem A Khan, but the aim was to reduce dependence on groundwater by generating 70 percent of water from surface sources by 2019.
Excessive extraction of groundwater would result in disasters like land subsidence and salinity increase, said Kazi Motin U Ahmed, a geology professor at Dhaka University. Groundwater table in the capital is depleting by three metres every year, according to the government estimate.
Architect Iqbal Habib, joint secretary of Bangladesh Poribesh Andolon, said the government had approved a big private housing scheme on floodplains in Rupganj of Narayanganj, where the master plan earmarked the Balu and Shitalakhya rivers as sources of drinking water.
M Firoze Ahmed, vice chancellor of Stamford University, said in his presentation that rainwater harvesting would help meet the domestic need of 160 billion cubic metres of water annually.
Rain harvesting devices should be installed on large government buildings, stadiums, railway stations and airports, said Hasin Jahan, director of WaterAid.
Sheikh Abdul Mannan, director of Rajdhani Unnyan Kartripakhha, said they were going to incorporate provisions for rainwater harvesting in the building rules and code.
Prothom Alo Associate Editor Abdul Qayyum moderated the discussion.