Two decades ago, people collected river water for household use. The river still flows by the 12 villages, but the 2.5 lakh residents dare not touch its pitch-black, foul-smelling water.

They are victims of "development" in nearby Dhaka.

Solid waste from the capital is washed into the Narai, which joins up and in turn pollutes the Balu and Shitalakhya rivers.

Three canals -- the Norai, Debdholai and Dolai -- flow through the 12 villages known as Barogram, carrying liquid and solid waste from Dhaka.

Waste from Malibagh, Basabo, Madertek, Kamalapur and Motijheel flow through the Debdholai and Norai canals. Untreated sewage from the Tejgaon industrial area, Gulshan, Banani, Rampura, Karwanbazar and Dhanmondi find its way into the canals and the Balu river before entering the Buriganga.

This correspondent found dead fish floating in the Narai. Ali Ahmed, 55, a boatman who has lived in the area for 32 years, said, "We are barely existing here. We cannot use the river water. Our cattle die if they drink this contaminated water. You can't sleep at night because of the mosquitoes. This pollution has changed our lives."

Residents have protested to Wasa and other government agencies about the pollution and staged numerous demonstrations in the last three years. The prime minister instructed an inter-ministerial meeting to take steps to resolve the problems. Officials, including the city mayor, Sadeque Hossain Khoka, assured residents that treatment plants would be established at Rampura. The pollution continues.

"We demonstrated three times to get rid of the problem," says Sheikh Babul Aktar, a local youth, at the Trimohini bazar. "The authorities have promised to resolve the problems of our villages, but nothing has been done. And so the water full of sludge continues to flow."