The Disastrous Flood of 1998 and Long Term Mitigation Strategies for Dhaka City

Abstract

The disastrous flood of 1998 was a result of excessive rainfall all over the catchment areas of the major rivers of Bangladesh. Dhaka City, which is surrounded by rivers on all sides, was seriously affected despite the completion of Phase I of the Dhaka Integrated Flood Protection Project (DIFPP). Water entered into the protected part of the city through hydraulic leakage such as buried sewerage pipes, breached and incomplete floodwalls, ungated culverts and inoperative regulators. The drainage network and retention ponds of the city were found to be in poor conditions and capacities of the pumping stations were found inadequate. There was a serious lack of coordination between the agencies responsible for flood protection and drainage of the city. These issues must be addressed to achieve long-term flood mitigation. In addition, feedback from both the experts and general public indicated that completion of Phase II of DIFPP was essential to bring the eastern part of the city under flood protection. Other structural measures suggested in this paper include installing and maintaining adequate drainage and pumping capacity and timely operation of regulators. This study also suggests a set of non-structural measures for flood mitigation that include protecting the retention ponds, raising public awareness on maintaining the city drains, introducing land zoning and flood proofing in the eastern part of Dhaka, and stream lining institutional bottlenecks.