While the Delhi government’s Health department is seeing red at the supply of contaminated water in parts of the city, Delhi Jal Board (DJB) officials blame it all on lack rainfall and a resultant dip in the Wazirabad reservoir.

According to officials, rain in some higher regions has also flushed water rich in floating material and other debris down the Yamuna. Result: working capacity of the Capital’s two main water treatment plants, at Wazirabad and Chandrawal, has come down by 35 per cent.

Going gradually down over the past few days, the level at the Wazirabad pond came down to 673.5 feet on Wednesday, against a mandated level of 674.5 feet, a DJB official said.

Asked about charges of supplying contaminated water, DJB Chief Executive Ramesh Negi said the problem is more prevalent in the unauthorised colonies. It is also triggered by Delhi’s fast depleting underground water level and excessive use of booster pumps, he said.

He said, “The level of (water in) borewells has gone down, and excessive use of boosters by residents has led to more contamination and less pressure in water supply lines in some areas.”

Negi said DJB is in constant touch with Haryana to ensure there is no cut in water supplied to Delhi. “The water level has gone slightly down at the Wazirabad pond and there was also some problem with pumping due to malfunctioning of an air valve,” he said.

But residents of areas — Rajouri Garden, Jama Masjid, Ballimaran and Inderpuri among others — have complained that they are getting sewage or slush from their taps. “We are sourcing water from outside for the last 20 days,” Rajouri Garden resident Usha Sachdev said. “The water we get is mixed with sewage, and smells as well.