Dhaka’s Sustainable Water Supply

Dhaka Water Supply and Sewerage Authority (DWASA) provides water across a service area  of  about  400  square  kilometers  in  Dhaka  City  and  its  surroundings.  It  has  been  relying heavily  on  groundwater  as  a  source  of  water  supply,  but  current  groundwater  abstraction  is beyond  sustainable  yields,  as  evidenced  by  a  rapidly  falling  water  table.  This  and  DWASA’s plan  to  further  expand  its  service  area  to  cater  to  a  growing  population  make  it  essential  to increase the surface water supply. However, the water quality in rivers surrounding Dhaka, such as  Buriganga  and  Sitalakhya  rivers,  is  rapidly  deteriorating  and  the  quantity  is  not adequate.

Dhaka waterfront at Buriganga River (Old Ganges).
Photograph Mariusz Kluzniak

 

water quality monitoring Dhaka

Meghna River, about 30 kilometers east of Dhaka, has been identified as one of the major new sources of water supply for Dhaka.  Two water intake points have been proposed, and the ADB-financed  Dhaka  Environmentally  Sustainable  Water  Supply  Project,  approved  in  2013,  is supporting development of one intake point along with a raw water transmission pipeline and a water  treatment  plant  Once  these  two  water  intake  points  and  associated  infrastructure are developed, Meghna River will account for more than 40% of the raw water for DWASA’s water supply by 2021 and will serve 8 million people with drinking water. To avoid deterioration of Meghna water quality and ensure sustainable water supply to Dhaka, it is critical to strengthen the monitoring and enforcement mechanism for Meghna River. Main beneficiary is the Department of Environment (DoE).

Deltares assessed the present state and trends in water quality. Therefore historical water quality data have been collected and the  river quality was monitored. Data have been stored and analyzed using Delft FEWS. An inventory of pollution sources and future development in the river basin has been made.  A water quality model has been used to assess the future water quality based on a midterm and long term scenario. An ecological survey was made to assess the ecological value of the river and also the economic value of the river was estimated.  Cleaner production at selected industries was piloted to demonstrate reduction strategies for pollution control. The results of the studies and surveys were used to make a water quality protection plan. We assisted the DoE to designate the relevant stretch of the river as an Ecological Critical Area.

The capacity of the DoE and DWASA was strengthened by an extensive training program and on-the-job training.

Passive sampling Dhaka