Dhaka is the capital of Bangladesh and nearly 10 million people lives in the greater Dhaka. Dhaka Water Supply and Sewerage Authority (DWASA) is responsible for supplying safe drinking water to the city dwellers. Nearly 6 million people live in DWASA service area, of which only 50% of the population are supplied with water through pipe network.

Traditionally, groundwater is considered to be the primary source (98%) for drinking water supply in Dhaka City due to cheaper cost of production and hyegenically safe. However, the city has been in overdraft for several years and reached to a maximum drawdown of 25m in 1997. Even with this, the present demand is partly met.

Under a subcontract with WSP International, the lead consultant for the World Bank-funded Fourth Dhaka Water Supply Project, SWMC in association with DHI has developed a groundwater model for greater Dhaka based on MIKE SHE modelling software. The objective of the study was to assess water availability in terms of quantity, quality and locations to meet the future water supply demand.

An area of 675 km² has been modelled, which is bounded by the Turag river on the west, Buriganga river on the south, Lakhya river on the east and Gazipur-Tangial road on the north. The model has been calibrated for the period 1991-1997. The calibrated model was applied to predict the groundwater table for the year 2006 and 2016. The model results showed that the drawdown would reach to a maximum depth of 35m and 45m in the year 2006 and 2016 respectively, if 95% of the total water-demand is met from groundwater.

The development of a conjunctive use of surface and ground water management plan is the only long-term sustainable solution for greater Dhaka. The present study demonstrated that with further refinement of some of the elements, the model can be used for detail analysis of the avaiable groundwater to various pumping stresses and conjunctive use options.