The water stock in the seven lakes that supply water to Mumbai dipped to 6.1% of the total capacity on Tuesday, the lowest in three years, according to The Times of India. The useful water stock in Upper Vaitarna stood at zero, while it was at 0.9% in Bhatsa lake.

The Brihanmumbai Municipal Corporation supplies 3,420 million litres of water daily, while the stock at the seven lakes stood at 88,743 million litres as on June 18. The stock in the reservoirs on the corresponding date in 2017 and 2018 were 2,70,000 million litres and 2,15,000 million litres. Mumbai requires 14.47 lakh million litres to last an entire year, reported The Hindu.

The seven lakes that supply water to Mumbai are Bhatsa, Tulsi, Vihar, Middle Vaitarna, Modak Sagar, Tansa and Upper Vaitarna. In April, the stock in the seven lakes stood at 26% of their total capacity.

Mumbai and its suburbs have received moderate rainfall since June 1, but the water level in lakes have not increased significantly as the rainfall in catchment areas has been scanty.

Vihar lake received 139 mm rainfall, while Tulsi has received 225 mm. These lakes, however, are the smallest among the seven and are located within the city limits. The total rainfall received in the five other lakes was less than 50mm since June 1.

The live storage or the useful water stock at Upper Vaitarna reservoir is down to zero. The lake’s lowest drawable level is 595.44 meters, but it stood at 590.25 meters on June 17. The corporation will now have to draw 70,838 million litres from the lake’s dead stock. The water stock at Bhatsa lake, which supplied the most amount of water to Mumbai, is down to 0.9%, and the corporation will draw around 1 lakh million litres from its dead stock.

An unidentified senior officer of Brihanmumbai Municipal Corporation’s hydraulic engineer’s department said the corporation can still draw from the dead stock of the Vaitarna lake system, which is made up of the Upper Vaitarna, Middle Vaitarna, Modak Sagar and Tansa lakes. “The system has water to last till July 31,” the officer said. “Even Bhatsa system has water till July 31. Together, the Vaitarna system has 11.31% stock.”

Bandra corporator Asif Zakeria said there have already been complaints of irregular water supply and that there were concerns that the corporation would reduce water supply if rains were poor.