Mumbai's Water Supply Reaches Three-Year High After Late Monsoon Rains

Mumbai's water reserves have swelled to a three-year high, with the seven lakes that supply the city reaching 88.81 per cent of their total useful capacity as of Tuesday morning, July 28, 2025. This comes after an initial delay in the monsoon onset, attributed to El Niño conditions, was offset by extremely heavy rainfall in July.

The Brihanmumbai Municipal Corporation (BMC) reported that combined useful content in the reservoirs stood at 12.85 lakh million litres against a total capacity of 14.47 lakh million litres. For comparison, on the same date in 2024, the stock was at 72.97 per cent. Four of the lakes—Tulsi, Vihar, Modak Sagar, and Tansa—are already at 100 per cent capacity, while Middle Vaitarna is at 90.3 per cent, Bhatsa at 87.36 per cent, and Upper Vaitarna at 77.51 per cent.

The island city relies on seven reservoirs spread across suburban Mumbai and neighbouring districts of Thane, Palghar, and Nashik. In the 24 hours ending Tuesday morning, Upper Vaitarna recorded 85 mm of rainfall, followed by 72 mm at Bhatsa and 57 mm at Modak Sagar.

Earlier in May, water stocks had plummeted below 25 per cent, prompting civic authorities to impose water cuts after the India Meteorological Department (IMD) projected below-normal southwest monsoon activity due to El Niño—a natural climate pattern where warming of ocean surface waters in the Pacific suppresses rainfall over India. The monsoon, which typically arrives in Mumbai by the first week of June, was delayed until June 30 this year. However, the Santacruz observatory recorded 1,490 mm of rainfall in July, far exceeding the monthly average of 919 mm.

Despite the surge in lake levels, the BMC has stated that existing water cuts will remain in place until total stocks reach 100 per cent capacity, which usually happens by the end of September. The city currently receives 3,850 million litres daily (MLD) against an estimated demand of 4,300 MLD, leaving a deficit of 450 MLD.

Rainfall over Mumbai was subdued from Tuesday morning, with the eastern suburbs receiving 19.39 mm, the island city 10.82 mm, and the western suburbs 10.68 mm between Monday and Tuesday. The IMD forecast light to moderate rain for the city and suburbs on Tuesday, and issued a yellow alert for Mumbai, Thane, and Palghar from Friday, warning of thunderstorms, lightning, moderate rainfall, and gusty winds up to 50 km/h. Rain activity is expected to increase closer to the weekend.