Heavy rainfall across Mumbai's lake catchments has sharply increased water storage in the city's seven reservoirs, offering relief after weeks of declining reserves, though the BMC has retained the 10 per cent water cut (File Photo)After weeks of worry over shrinking reserves, heavy rain over Mumbai’s lake catchments has given the city’s water stock its biggest boost of the monsoon so far.The combined storage in the seven lakes supplying Mumbai rose from 16.92 per cent of capacity on Monday to 28.92 per cent on Tuesday morning, a jump of 12 percentage points in 24 hours, according to data released by the Brihanmumbai Municipal Corporation (BMC). In volume terms, the stock increased by 1.74 lakh million litres, from 2.44 lakh million litres to 4.18 lakh million litres which is a 71 per cent increase.The rise follows two days of intense rainfall across the lake catchments after a rain deficient June had pushed reservoir levels down to around 6 per cent, forcing the BMC to impose a 10 per cent water cut across the city from June 15. The civic body later tightened restrictions on commercial establishments and construction sites as reserves continued to decline.The seven lakes, Bhatsa, Upper Vaitarna, Middle Vaitarna, Modak Sagar, Tansa, Tulsi and Vihar, together have a storage capacity of 14.47 lakh million litres and supply Mumbai’s daily drinking water.Also Read | Powai lake overflows after heavy rain in Mumbai; overall water stock in lakes shows marginal improvementAccording to the BMC, the sharp rise came after heavy rainfall across the catchment areas between Monday and Tuesday morning. Modak Sagar recorded the highest rainfall at 345 mm, followed by Tansa (322 mm), Middle Vaitarna (235 mm), Upper Vaitarna (212 mm), Bhatsa (172 mm), Tulsi (160 mm) and Vihar (151 mm).Over the past two days, the reservoirs have gained nearly 15 percentage points, bringing relief after a prolonged dry spell at the start of the monsoon.Despite the improvement, the BMC said the 10 per cent water cut will continue for now. Officials indicated that the curbs would be reviewed only after the reservoirs record a further rise.Story continues below this adEven after Tuesday’s sharp increase, the city’s water stock remains well below last year’s levels. On the corresponding day in 2025, the reservoirs were 68 per cent full, more than double the current storage.Earlier this month, Powai Lake overflowed after heavy rain. However, the lake is used for industrial purposes and is not part of Mumbai’s drinking water supply system.