Mumbai's Lake Levels Dip To 30%, BMC Secures Reserve Water Amid Heatwave Concerns

The water stock in the seven lakes supplying Mumbai has dropped to 30.24%, amounting to 4.37 lakh million litres (ML), enough to last around 110 days. While the BMC has no immediate plans for water cuts, officials are closely monitoring the situation, with rapid evaporation due to high temperatures emerging as a key concern. 

To ensure supply in case of a delayed monsoon, on BMC's request the state government has approved access to 1.81 lakh million litres of reserve water from Bhatsa and Upper Vaitarna. Mumbai requires a total of 14.47 lakh ML of water in its lakes by October 1, for uninterrupted supply throughout the year.

The city receives water from seven lakes — Tulsi and Vihar, located within Mumbai, and Bhatsa, Tansa, Upper Vaitarna, Middle Vaitarna, and Modak Sagar, situated in the districts of Thane, Palghar, and Nashik. Although the monsoon arrived late last year, heavy rainfall continued until September, helping the lakes maintain a healthy water stock. However, the rising temperatures are causing rapid evaporation, leading to a steady decline in water stock.

Mumbai usually sees monsoon onset by June 11, but in recent years, rains have been delayed, often intensifying only in the last week of June. To ensure backup supply, the BMC requested access to reserve stocks from Upper Vaitarna and Bhatsa lakes. "The state government approved 68,000 ML from Upper Vaitarna and 1.13 lakh ML from Bhatsa. While this reserve will be used only if needed, the current stock is sufficient to last until mid-July. However, intense heat and high evaporation continue to pose a threat to water reserves," a BMC official said.

The seven lakes supply 3,950 ML of water daily to the city. The BMC utilised some of the reserve water stock from Upper Vaitarna lake till the catchment areas of other lakes received heavy rainfall in July last year. Also, a water cut of 10% was imposed for a month, which was withdrawn by August 9.