Fieldtrip on Urban Flood Management in Dhaka

The project team of NWO WOTRO Dynamic Deltas undertook a one-day field visit in Dhaka on the topic of urban flood management. This visit was organised by Farhana Ahmed of CEGIS, who is currently engaged in a PhD research project on Adaptation Tipping Points for urban flood management. The purpose of the field visit was to gain a better understanding of the main issues and recent (structural) responses related to urban flood management. Dhaka suffers from a range of urban flooding problems such as environmental pollution and a lack of adequate drainage services. The flood protection works comprise about 30km of earth embankments along the rivers Turag, Buriganga and Tongi Khal; and about 37 km of raised roads and flood walls along Buriganga river. Furthermore, there are a number of sluice gates, 1 regulator and 4 pumping stations (Kallyanpur, Goranchand Bari, Dholia Khal and Rampura). The team first visited the Rampura pumping station and sluices. The pumping station has a total capacity of 850 cumec, and starts pumping before the water level in the lakes reaches the danger level of 5.5 meter. The catchment area includes Hatirjheel, Banani lake, Ghulshan lake, Dhanmondi lake and Mohakhali lake. The second visit included a stop at the Buriganga river and at a specific section of the flood wall (near the Ahsan Manzil). After making a tour through the Ahsan Manzil (Pink Palace) and a lunch at the Military Museum, the team continued the field trip with a visit of the Western embankment. This embankment has been constructed following the recommendations of the Bangladesh Flood Action Plan (FAP). Md Mostafizul Rahman Shibly (an expert from CEGIS) explained that the embankment is a good-practice example of a Multi-functional Flood Defence, since various economic and social functions have been integrated with flood protection. This was apparent from the economic activities going on at the field visit site, namely sand extraction and agriculture. The multiple use of the embankment in Dhaka is different to the common situation in the Netherlands, where the Water Boards have the responsibility to maintain the designed profile of the primary and secondary dikes. Yet, there are also some good examples of Multi-functional Flood Defences in the Netherlands , such as the primary dike Voorstraat in Dordrecht. This dike is also a shopping street, on which a large number of monumental buildings is located. The field visit ended with a Deshi dinner, offered by the host organisation CEGIS to the Dynamic Deltas team. At the dinner, ideas where exchanged for future collaboration between Dynamic Deltas and ongoing and planned CEGIS projects.