Mumbai’s seven key water reservoirs were holding a combined 13,70,502 million litres of useful water as of 6 am on Saturday with the stock at 94.69% of live storage capacity, according to the BMC Hydraulic Engineer’s Department report.
The seven reservoirs Upper Vaitarna, Modak Sagar, Tansa, Middle Vaitarna, Bhatsa, Vihar and Tulsi continue to record healthy storage levels amid the ongoing monsoon.
The combined stock is marginally lower than the 94.95% recorded during the corresponding period in 2025, while matching the 94.69% level recorded in 2024.
Vihar Full, Modak Sagar At 99.99%
Among the reservoirs, Vihar Lake was at 100% of its live storage capacity, holding 27,698 million litres of useful water. Modak Sagar stood at 99.99%, with 1,28,910 million litres, while Tansa was at 99.02%, holding 1,43,652 million litres.
Tulsi was at 99.66%, with 8,019 million litres, while Bhatsa and Middle Vaitarna stood at 94.76% and 94.54%, respectively.
Upper Vaitarna, meanwhile, recorded 88.01% live storage, with 1,99,818 million litres of useful content.
Lakes Continue To Receive Rainfall
The report showed that the reservoirs received rainfall over the past 24 hours. Upper Vaitarna and Middle Vaitarna recorded 24 mm each, while Modak Sagar received 28 mm. Tansa recorded 11 mm, Bhatsa 4 mm, Vihar 4 mm and Tulsi 10 mm.
Cumulative rainfall figures remained substantial, with Upper Vaitarna recording 3,535 mm, Tulsi 3,406 mm and Modak Sagar 2,970 mm.
Several Lakes Have Been Overflowing Since July
The BMC report also recorded the dates on which several reservoirs began overflowing. Vihar started overflowing on July 7 at 9 pm, followed by Tulsi at 11.43 pm the same day.
Tansa Dam began overflowing on July 22 at 8.51 am, while Modak Sagar started overflowing on July 23 at 2.07 am.
The report further noted that the Middle Vaitarna WSPCO gate was closed on July 6 at 2 pm, while releases from Upper Vaitarna were stopped at 10 am the same day.
Upper Vaitarna’s Role In Mumbai’s Water Supply
Upper Vaitarna has long been an important component of Mumbai’s water infrastructure. According to BMC’s historical records, the Upper Vaitarna scheme was developed as a multipurpose hydroelectric-cum-water supply project and was fully commissioned in 1972. The project added substantial water supply capacity to Mumbai, with water released downstream eventually contributing to the city’s supply through the Vaitarna system.
BMC records show that Mumbai’s water system now draws raw water from seven major reservoirs, including Upper Vaitarna, Middle Vaitarna, Modak Sagar, Tansa and Bhatsa outside the city, along with Vihar and Tulsi within Mumbai.
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The Upper Vaitarna scheme was also designed to generate hydroelectric power before releasing water into the Vaitarna river system. BMC records state that the project was commissioned in 1972 and increased Mumbai’s water availability by hundreds of million litres per day.
Comfortable Water Position For Mumbai
With the seven reservoirs collectively at nearly 95% of live storage capacity and several lakes already touching or approaching full capacity, Mumbai currently has a strong water stock position.
The sustained rainfall and continued inflows have helped replenish the city’s principal water sources during the 2026 monsoon, providing a comfortable buffer for Mumbai’s water supply as the rainy season progresses.
