Mumbai: Rainfall races ahead, but city lake levels lag

Bhatsa’s water stock was 1,45,654 million litres on Tuesday. File pic

The 10 per cent water cut imposed across the city will not be rolled back for now as Brihanmumbai Municipal Corporation (BMC) officials feel the monsoon has not picked up yet. The collective water stock of lakes was 3.82 lakh million litres or 26.36 per cent on Tuesday morning.

On July 11 last year, the figure was 5.83 lakh million litres or 40 per cent. The present stock should have been at least 30 to 35 per cent, according to officials. The cut was implemented due to the delay in the monsoon's arrival. To supply water to the city smoothly throughout the year, a stock of 14.47 lakh million litres is required.

The total storage capacity of Tansa is 1,45,080 million litres. File pic

"We are hoping the monsoon will pick up soon. We take a decision on continuing or cancelling the water cut by the last week of July," said a BMC official. The official added, "Due to the delay in the arrival of the monsoon, lake levels had decreased. Therefore, more rain is required this year. Approximately 2,000 to 2,100 mm rainfall on an average is required to fill all lakes."

According to the data, Tulsi lake's catchment area received the highest rainfall - 1,311 mm - but it is only 63.64 per cent full. Tulsi is the smallest lake that supplies water to Mumbai. Upper Vaitarna's catchment area though received the least rainfall - 684 mm.

The useful content of Upper Vaitarna, the second largest source of water for the city, is 1.90 per cent. The total capacity of the lake is 2.27 lakh million litres, but there are only 4,319 million litres of water in the lake. Mumbai surpassed its monthly quota of rainfall for June despite a two-week delay in the monsoon's arrival. Though July has seen lower rainfall than the average figures, it is expected to pick up.