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
Though the expensive Hatirjheel project was mainly taken up to reduce traffic congestion, conserve rainwater, prevent floods and water stagnation, improve water filtration and add to the aesthetic beauty of the capital city, the project has spectacularly failed at preventing floods. Instead, it is creating water stagnation throughout large parts of the city after each rainfall.
According to sources involved with the project, nine mechanical scanners redirect Dhaka Water Supply and Sewage Authority’s (Wasa) drains and water from surrounding houses into Hatirjheel after the rains. But the scanners are unable to handle the water flow if rainfall exceeds 50mm, flooding the entire region. The flooding of Hatirjheel was at fault for the stagnant water in Dhaka’s Dhanmondi, Karwan Bazaar and adjacent areas on July 26.
Jamal Akhter, the director of the Haitrjheel project, said: “We use mechanical scanners to filter and clean the water that is redirected into Hatirjheel. But when there is excessive rainfall, the scanners cannot handle the pressure. We are then forced to open the lids of the scanners, which allow dirty water from the households nearby to flow into the water body and pollute the environment.”
“If we want to stop the pollution of Hatirjheel’s waters, we will have to separate the storm drainage and rainwater drainage systems. But Wasa is not at all concerned with this. If we could have separated the two, we could just have let rainwater flow directly into Hatirjheel since rainwater is not dirty. It would also have reduced the time it takes to clean the sewerage line’s flow of water. Now, since they both get mixed together, we have to filter both the waters together.”
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.
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Is Hatirjheel project responsible for waterlogging?
Shahed ShafiqPublished at 02:46 PM July 30, 2017Last updated at 07:51 PM July 30, 2017
Is Hatirjheel project responsible for waterlogging?
A snapshot of Hatirjheel Lake in Dhaka Mahmud Hossain Opu/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
Though the expensive Hatirjheel project was mainly taken up to reduce traffic congestion, conserve rainwater, prevent floods and water stagnation, improve water filtration and add to the aesthetic beauty of the capital city, the project has spectacularly failed at preventing floods. Instead, it is creating water stagnation throughout large parts of the city after each rainfall.
According to sources involved with the project, nine mechanical scanners redirect Dhaka Water Supply and Sewage Authority’s (Wasa) drains and water from surrounding houses into Hatirjheel after the rains. But the scanners are unable to handle the water flow if rainfall exceeds 50mm, flooding the entire region. The flooding of Hatirjheel was at fault for the stagnant water in Dhaka’s Dhanmondi, Karwan Bazaar and adjacent areas on July 26.
Jamal Akhter, the director of the Haitrjheel project, said: “We use mechanical scanners to filter and clean the water that is redirected into Hatirjheel. But when there is excessive rainfall, the scanners cannot handle the pressure. We are then forced to open the lids of the scanners, which allow dirty water from the households nearby to flow into the water body and pollute the environment.”
“If we want to stop the pollution of Hatirjheel’s waters, we will have to separate the storm drainage and rainwater drainage systems. But Wasa is not at all concerned with this. If we could have separated the two, we could just have let rainwater flow directly into Hatirjheel since rainwater is not dirty. It would also have reduced the time it takes to clean the sewerage line’s flow of water. Now, since they both get mixed together, we have to filter both the waters together.”
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 having to use whatever they can to get by the waterlogged streets Mehedi Hasan/Dhaka Tribune
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.