Modak Sagar lake, one of the seven reservoirs that supply potable water to Mumbai and its suburbs, has started overflowing following incessant rains in the catchment area, an official said on Friday.
The Modak Sagar lake built on the Vaitarna river in neighbouring Thane district started overflowing at 10.52 pm on Thursday night, he said.
This is the fourth lake, after Vihar, Tansa and Tulsi, to overflow this monsoon season.
Thane District Information Officer Manoj Sanap said that after it started overflowing, two gates of the dam were opened to release 6,000 cusecs of water.
Tulsi lake located in the Sanjay Gandhi National Park was the first to overflow this year. It started overflowing on July 20.
Mumbai receives 3,800 MLD (millions of litres per day) water from the seven reservoirs -- Bhatsa, Upper Vaitarna, Middle Vaitarna, Tansa, Modak Sagar, Vihar and Tulsi -- located in Mumbai, Thane and Nashik districts.
According to the civic administration, the aggregate water stock of these reservoirs on Friday morning was 68 per cent.
Notably, the BMC imposed a 10 per cent water cut here from July 1, after the level of lakes supplying water to Mumbai went down due to inadequate rainfall at that time in their catchment areas.
The Powai lake in the metropolis also started overflowing earlier this month, but its water is not used for drinking purpose, Brihanmumbai Municipal Corporation (BMC) officials said.
In Thane district, the Barvi dam is about to reach its full capacity. The water level of the dam at 7 am on Friday was 71.40 metres, while the overflow level is 72.60 metres, an official said.