Ashulia, Banashree, Aftabna-gar, Meradia, Baunia, Badda, Kalyanpur, Amin Bazar, Hatirjheel and many other water catchment areas have been indiscriminately grabbed by public and private organisations and unscrupulous developers.

"Mindless filling of city canals and other water bodies has destroyed water retention capabilities exposing the city to frequent inundation," the experts observed.

With the absence of such water bodies the 12-hour incessant rain drowned the capital in a vast pool of water, paralysing normal life yesterday. Torrential rains that began midnight Saturday continued till noon yesterday, inundating a major part of the city.

Commuters, residents and vehicles were stuck, as the rainwater could not recede because of poor sewerage systems. Massive road digging by different utility service providing agencies at many points added to their miseries.

Motijheel, Gulistan, Nawab-pur, Shantinagar, Kakrail, Fakirapul, Paltan, Tejgaon, Malibagh, Gulshan, Mirpur and many other low areas went under water because of the heavy downpour.

"All development plans including the recent Dhaka Master Plan have clearly marked these areas for flood retention and the Wetland Conservation Act bars development of land on such water bodies," said a source at Rajuk, the government's city development agency. "The Wetland Conversation Act 2000 states that no one has the right to develop any wetland, flood flow zone or catchment areas," he said.

But a number of land developers more often aided by government officials and politicians have illegally occupied and filled up these areas under the very nose of the authorities.

These areas, experts said could hold a large volume of floodwater and protect many areas from waterlogging. In addition, rivers such as the Buriganga and Turag are encroached. In many parts the rivers look like narrow canals.

"Water bodies, canals and ponds, if saved, could consume nearly one third of present volume of floodwater," said an official of Flood Forecasting Centre of Bangladesh Water Development Board (BWDB).

"We have to stop further encroachment and recover stolen water bodies from dishonest land grabbers to protect the city," a Dhaka Water and Sewerage Authority (Wasa) official said. "These occupiers are very influential and politically connected," he added.

At a recent inter-ministerial meeting 26 canals were identified for urgent recovery. Rajuk, Dhaka City Corporation (DCC), Wasa and the office of the Deputy Commissioner (DC) were asked to identify the lost canals and take measures for the recovery while the Home Ministry has been asked to facilitate the initiative.

To reduce residents' sufferings Wasa pulled down illegal structures on the different canals. Wasa officials claimed that until end May, they had cleaned more than 100 km of drainage pipes. "We focused on pulling down illegal structures over canals, clean them and make sure the flow of water is smooth and included cleaning of box culverts too," said an official of Wasa drainage circle.

Wasa started the canal recovery drive on March 29 in Mirpur with the cooperation of the Ministry of Home Affairs, Rajuk, DCC and Dhaka District Administration, and claimed they have made a remarkable progress in salvaging lost canals.