August 20, 2025: Mumbai has been battered by days of relentless monsoon rainfall, paralysing large parts of the city while simultaneously replenishing its water reserves. On Wednesday, the Brihanmumbai Municipal Corporation (BMC) opened all 38 gates of the Tansa dam after water levels surpassed the danger mark. The reservoir, with a storage capacity of 145,080 million litres, had reached full capacity, prompting officials to initiate a controlled release to protect dam safety and regulate downstream flow.
According to BMC data, the combined water stock in the city’s seven lakes supplying drinking water rose to 95.12% by Wednesday afternoon, compared with 92.42% a day earlier. Officials attributed the rapid rise to continuous heavy rainfall across catchment areas over the previous 24 hours.
The India Meteorological Department (IMD) has issued an orange alert for Mumbai and its suburbs, forecasting heavy to very heavy rainfall at isolated locations, along with gusty winds of 45–55 kmph. Radar imagery indicates persistent monsoon activity, with no immediate signs of relief.
Other reservoirs serving the city have also witnessed a sharp increase in water levels. As of 20 August, total storage across all reservoirs stood at 1,319,640 million litres, or 95.12% of overall capacity. Modak Sagar has already reached 100%, Middle Vaitarna is at 98.69% , Upper Vaitarna at 91.51%, and Bhatsa at 93.19% . The smaller Vihar and Tulsi lakes have also touched full capacity.
Mumbai’s daily drinking water supply comes from these seven sources: Upper Vaitarna, Modak Sagar, Tansa, Middle Vaitarna, Bhatsa, Vihar, and Tulsi. With several reservoirs brimming, the BMC said it is maintaining close watch over inflows to ensure both safety and sufficient supply to meet the city’s growing demand.
Source: Mid-day
