Mumbai's seven lakes, crucial sources of water for the city, have recorded a worrying decline in reserves, hitting a three-year low at 25.34% of their total capacity. Starting the year with usable stocks at 68%, which amounted to 9.52 lakh million litres in January, the reserves dwindled to 44% in March and have now plummeted to 25% in April, totaling 3.66 lakh million litres. This sharp depletion raises apprehensions regarding the adequacy of current levels to meet Mumbai's water demands, sparking concerns over potential scarcity.
Speaking to LokmatTimes.com, an official from the Brihanmumbai Municipal Corporation (BMC)'s hydraulic department indicated no immediate water cuts. However, they will reassess water availability between May 15 and 20. The official noted that the decreased levels are primarily due to last year's 6 to 7% lower rainfall and increased temperatures, leading to higher evaporation rates, altering water quality, and impacting ecosystem balance. The BMC official said, "The increase in temperature increases the evaporation from the free lake surface, and lowering the lake level. If evaporation increases, we will review the water supply position and accordingly decide on strategies. For now, we are relying on additional reserve stock sanctioned by the State government."
Mumbai heavily depends on monsoon precipitation for its yearly water provision, drawing from seven lakes: Tansa, Bhatsa, Modak Sagar, Tulsi, Vehar, Upper Vaitarna, and Middle Vaitarna. Present levels in five lakes owned by the BMC are as follows: Modak Sagar at 33,355 million litres (25.87%), Tansa at 58,328 million litres (40.20%), Middle Vaitarna at 20,021 million litres (10.34%), Vehar at 10,342 million litres (37.34%), and Tulsi at 3,412 million litres (42.40%). State-owned lakes report Upper Vaitarna at 72,209 million litres (31.08%) and Bhatsa at 1,69,152 million litres (23.59%).
The official expressed confidence that reserved stock from the state will ensure adequate supply until the monsoon, with plans to tap into 91,930 million litres from Upper Vaitrana and 1,33,00 million litres from Bhatsa, in addition to current stocks. BMC pays for water from Bhatsa and Upper Vaitarna and will also be paying for additional stock agreed upon by the State from Bhatsa and Upper Vaitarna.
In January, BMC officials mentioned the possibility of implementing water cuts after three months, taking into account evaporation rates. However, BMC has opted to delay the decision for an additional month. Currently, the BMC, which provides water to Thane as well, is reviewing its water distribution strategy, contemplating necessary adjustments in allocations, which may involve reducing supply.