A government-formed high-powered committee comprising representatives from Dhaka Water and Sewerage Authority (Wasa) and other government agencies is conducting the survey aiming to restore navigability of the canals.

Identifying the natural canals in and around the city the committee is likely to submit its findings to principal secretary to the prime minister tomorrow.

Apart from the officials of Wasa's Drainage Circle, the committee has representation from Dhaka Transport Coordination Board (DTCB), Dhaka City Corporation (DCC), Rajdhani Unnyan Kartripakkha (Rajuk) and Deputy Commissioner (DC), Dhaka.

Sources said following an inter-ministerial meeting which discussed the matter in the wake of severe waterlogging in the city, the Prime Minister's Office directed Dhaka Wasa to detect locations and present situation of the water bodies.

The city experienced worst form of waterlogging last month amid a heavy downpour as most of the natural channels of water and retention basins are either occupied or filled up. "The government will try to put an end of it," said a DTCB official.

Experts said canals help prevent flood and keep drainage system working properly. Moreover, it acts as natural water reservoir during summer.

A high official of DTCB said the concrete-made drains actually work like a reservoir rather than a channel for water to pass. "Neither can they absorb water, nor can they carry water to canals or basins as most of them are filled up. Thus, they overflow," he said explaining the reason of waterlogging during floods and monsoon rain.

According to a CS map (Cadesdal Survey map) submitted to the committee by the office of DC (Land), the city has a total of 35 canals. But the number may exceed 44 as all of them could not be identified due to stagnant water, an insider of DTCB said.

Only 14 of the 35 canals are now flowing normally while the others have lost their natural flow, sources at the DC (Land) office said. Five of them -- Rayerbazar canal, Arambagh canal, Gopibagh canal, Paribagh canal and Shyampur-Kadamtali canal -- have entirely been filled up for construction of roads.

Gabtoli canal, Meradia-Gazaria canal, Dholaikhal 1 and 2 and Hazaribagh canal are partially flowing. Some of the canals such as Ibrahimpur canal, Meradia-Gazaria canal and Ramchandrapur canal are illegally occupied. At least five feet area on either bank of Ibrahimpur canal now hosts illegal makeshift structures, slums and a concrete wall.

Wasa Sources said the canals in 137 square kilometer area inside Dhaka Protection Embankment face man-made barriers to discharging water from the areas including Rayerbazar, Hazaribagh, Kazipara, Shewrapara, Shyamoli and Adabor. They said city people would get rid of waterlogging once their navigability is restored.