Also Read- Can Dhaka’s waterlogging problem really be resolved?
He said the capital city's canals and drainage systems are extremely ineffective, causing water to stagnate each time it rains. The Hatirjheel's scanners cannot clean the combined water flow from sewage lines and rainfall at the same time. This was the chief cause of the flooding that occurred after the rains on the night of July 26. Prof Mujibur Rahman, head of Buet's Civil Engineering Department, said: “From the very beginning we had warned that Wasa's drainage capacity was not sufficient to supply the nine scanners at Hatirjheel. This causes water stagnation because of improper water flow. The Dhaka Wasa's drains are clogged with solid waste. They have not improved their drainage systems in the last 40 years. This forces the scanners to be opened during excessive rainfall, which pollutes the Hatirjheel's waters.” “Our advice was to create a sewage treatment plant to filter sewage flow. It was supposed to be built 5km from Rampura bridge. The plant was supposed to keep waterflow constant after filtering the sewage. But no one listened to our advices then,” he added.
People have to use whatever they can to get by the waterlogged streets Mehedi Hasan/Dhaka Tribune According to Dhaka Wasa data, almost 600,000 tonnes of sewage from the area between Dhanmondi and Rampura flow through Hatirjheel into the Balu river and eventually into the Shitalakkha river.
At an event on July 16 hosted by the Dhaka North City Corporation, the FDC flyover between Hatirjheel and Karwan Bazaar was said to be at fault for the waterlogging situation in Karwan Bazaar and surrounding areas. The area's water drainage systems were said to be closed because of the flyover, resulting in the whole area becoming waterlogged.
One of Hatirjheel's mechanical scanners, placed adjacent to the Sonargaon Hotel, intercepts sewerage and rain waterflow from Karwan Bazaar, Panthapath, Dhanmondi, Kalabagan, Kathalbagan, Bangla Motor and surrounding areas. But on Wednesday, the whole area was submerged after only 65mm of rain. Mogbazaar, Modhubaag, Ulon, Mohanagar Project, Daspara, Rampura, Merul, Badda, Gulshan, Tejgaon and other areas near Hatirjheel were also similarly flooded.
The DSCC's Superintendent Engineer Asaduzzaman said: “Not enough water can pass through the Hatirjheel's sluice gates. There are three mechanical scanners at each of the gates. This causes some resistance to the usual flow of water. The gates are also not that wide. This makes it impossible for them to operate during heavy rains. So the gates are forced to be opened, causing situations like that on Wednesday.”
The project was approved in October 2007. Although the project was supposed to be completed in three years by June 2010, work on it began in December 2008. The project was later redesigned and allotted another 1.5 years. Prime Minister Sheikh Hasina inaugurated the project on January 2, 2013 and opened it to the public. The Bangladesh military's Special Works Organisation (SWO) was in charge of overseeing the project.