Analyzing the Role of Goranchatbari Pump Station and Its Performance in Reducing Water Logging Problem of Dhaka City

Dhaka, the capital city of Bangladesh, is one of the largest and the most densely populated cities in the world. Being located in the tropical region with intense rainfall of around 2300 mm/yr, it undergoes recurring waterlogging almost every year. The city dwellers suffer a lot due to such waterlogging, especially during the monsoon season from May to October. Being cordoned by a flood protection embankment, few pump stations of the city mostly do the job of removing logged water to the nearby rivers. The main objective of the study is to investigate the causes of waterlogging and the performance of a pump station to reduce it, which is located at Goranchatbari in the north-western part of the city. Satellite image analysis and GIS-based mapping of drainage network, field visits, questionnaire survey, rainfall and pump station data analysis and reports in the newspaper were analyzed to get a preview of the causes of waterlogging. It concluded that unplanned drainage, blockage of existing drains and encroachment and inadequate pumping facilities are the main reasons for flooding in the region, so that water cannot reach up to the pump station. For precise analysis, the catchment area was divided into five zones of almost similar land uses. Based on the future projections of sub-catchment land uses as well as future climate change scenarios, projected change in runoff was estimated. It has been found that under both the scenarios, the drainage congestion will aggravate further. Suggestions were then made to identify the hotspots, fix areas of drainage blockages, reexcavation of extinct canals and increase the capacity of retention pond in front of the pump station.