Drinking water has become contaminated with sewage and dirty water in certain areas submerged in floodwater in the city, said affected residents.

In order to escape the severe water crisis, some of the residents of Madartek, Goran, Nandipara, Trimohini and Bashabo were forced to leave their homes during the past week and stay at relatives' houses.

Residents who remained have been fetching drinking water from other neighbourhoods and coping with the contaminated water for the rest of their daily uses, as regular water supply of Dhaka Water and Sewerage Authority (Wasa) has been polluted by contact with stagnant floodwater mixed with sewage, said the residents.

The knee-deep stagnant floodwaters have invaded Wasa's water supply lines either through leakages or through underground private water reservoirs, said experts.

A businessman and resident of Madartek Natunpara, Md. Masudur Rahman had to send his wife, daughter and younger brother to his sister's house in Goran area in the face of water crisis. He himself has been surviving at home with drinking water brought from his sister's house.

"The Wasa water, contaminated with water borne sewage, gives bad odour and looks blackish," said Rahman, "It has been unfit for daily uses let alone drinking for more than last one week."

Several hundred families in the area are faced with the crisis, he said.

"One of my friends, Mujibul Haq Babu, who lives at a place close to Wasa's water pumps at Madartek and Goran, complained last night of contamination in water," said Rahman.

Similar crisis has surfaced in Merul Badda too.

According to a source, the Wasa water supply lines have leakages and cracks at many points, but it is difficult to ascertain their exact locations while they are submerged.

"Contaminated water may easily penetrate into the lines when pressure of water flow is low," said an engineer of Wasa, requesting anonymity.

Shahidur Rahman Pradhan, managing director (in-charge) of Dhaka Wasa, said, "There is no mechanism to detect cracks and leakages in the supply lines when inundated with floodwater."

"But we have kept all the water pumps running round the clock to keep the water flow strong so that dirty water cannot enter into the supply lines," he said, suggesting that every house owner should take protective measures so that underground water reservoirs at private houses do not get inundated by flood water.

"Contaminated water too can be used, if it is boiled for 30 minutes," said the Wasa MD.

According to a source, Wasa's water supply lines have cracks and leakages, through which filthy water may penetrate and pollute the water anytime circulating through supply net. That apart, the said areas are notorious for illegal water connections with plastic pipes, through which dirty water may easily enter the supply lines.

In fact, the ground floors of many buildings in the said areas are already submerged in floodwater, and underground water reservoirs of private houses might have been contaminated with the dirty water.

As a result, water supply in the entire adjoining area may be polluted, since the supply line is an inter-linked network, said the source.

Executive engineer of Wasa zone-6 RJM Rabiul Kaizer said casually, "The matter is too technical to explain instantly, come down to my office sometime."

Executive engineer Md. Saiful Hossain, head of Flood Forecasting and Warning Centre (FFWC), told The Daily Star that the water level of six rivers including Buriganga, Shitalakhhya, Balu, Turag and Tongi canal around the capital city would remain stable during next 24 hours. His prediction was based on analysis of the overall situation upstream and volume of rainfall.

"Water level of the said rivers will definitely start receding from day after tomorrow," said Hossain.

Water in the river Buriganga reportedly flowed 5 centimetres above the danger level yesterday morning. Floodwater started approaching the eastern fringe of the capital city a week back, as water levels of all major rivers surrounding the city continued to swell with receding water from upstream. Three quarters of Bashabo, Nandipara and Trimohini went under floodwater over last week.

Hospital sources said that the number of patients with diarrhoea, cholera and other waterborne diseases is increasing everyday.