Present Status of the Drainage Network of Dhaka City: In reference to Recent Flooding Conditions
Dhaka, the capital of Bangladesh surrounded by river networks, which is, in turn, connected to a network of internal drainage system. Flood occurs frequently in this mega city due to both river flood and drainage congestions. Flood is the most common kind of disaster the city faced during the last fifty years since 1954. Flood management of the city is crucial for reducing the enormous loss to capital investments and sufferings to human beings. The drainage of the city has only covered 140 sq. km, which is 38% of the total city corporation area, and it’s deteriorating for the last few years due to many development works. The 2010 and 2004 flood was due to excessive rainfall over the catchments area of the Ganges-Brahmaputra-Meghna (GBM) river basin. In addition, the impact of the lunar cycle and its resulting high tide was responsible for slow recession of floodwaters. The causes of flooding inside the protected area were due to an inadequate or inefficient drainage network. Flooding that’s occurs in the city due to drainage congestion arising out of incessant rainfall. This kind of flooding causes damage to road surface, communication systems and public utility services.