Floodwaters are receding by a trickle after submerging up to two-thirds of the country, but many residents are still cut off and in dire need of food and clean water.

The United Nations said it would hold a donors' meeting tomorrow to coordinate immediate relief and launch an international appeal next week to raise funds for post-flood rehabilitation, AFP said.

"Normally the (Bangladesh) government handles the annual flooding caused by the monsoon but the early onset of heavy rains this year has stretched their response systems," said UN Resident Coordinator Douglas Coutts.

"The UN agencies along with the donor community and non-governmental organisations are helping to fill the gaps in this relief effort," he said.

The flooding, which laid property and infrastructure waste in 6.6 billion dollars, is the heaviest seen in Bangladesh since its worst ever floods of 1998 which left more than 700 dead and 21 million homeless, AFP reports.

The disaster management ministry said about 1.5 million people were languishing in 4,994 shelters, while Unicef said a large number of children and women who have taken refuge in makeshift shelters run the risk of contracting diseases, official news agency BSS said.

WASA EFFORTS

The Water and Sewerage Authority (Wasa) is struggling to pump wastewater and floodwaters out of the capital into surrounding rivers as sluice gates remained closed for 24 days.

The floodwaters have submerged around 800 kilometres of Wasa pipeline, which includes 600 kilometres of water supply line, 150 kilometres of sewer and 50 kilometres of drainage line.

Wasa has set up 104 pumps in a series of areas including Rampura, Janapath, Nababganj, Shahidnagar, Islambagh, Swarighat, Kalunagar and Sikder Medical College Hospital.

Wasa set up about 50 pumping machines beside Rampura Bridge in Khilgaon, 44 of them are now working. The Water Development Board in a press release on Sunday said it set up six powerful pumping machines with a capacity to pump out 81 cubic feet water a second.

"The pumps we are using are old and mostly run on diesel engine that is less efficient than the electric ones," a Wasa official said.

Officials said the encroachment of canals and wetlands in and around the city and solid waste overwhelmed the drainage system -- the major cause of waterlogging.

According to Wasa, city dwellers use about 150 crore litres water that produces about 100 crore litres of wastewater in addition to waste from several hundred tubewells and industrial waste. The quantity of wastewater is much more than the capacity of Wasa pumping machines.

The floods swamped much of the capital, mostly rushing in through its eastern fringe unprotected by any flood control dam, the Wasa official said, describing an embankment there as essential to preventing the floodwaters coming in.

The Flood Forecasting and Warning Centre yesterday said the rivers and canals around the city fell a couple of centimetres on average, although they are still flowing above danger marks.

(AFP and BSS contributed to this report)