Within a single day of rainfall on Thursday, the water stock in the seven lakes that supply drinking water to Mumbai surged to 25.17 per cent (3,64,233 million litres or ML) by Friday morning, up from 13.18 per cent (1,90,771 ML) on Thursday morning. This marks a rise of 1,73,662 ML in just 24 hours. At full capacity, these lakes can hold a total of 14,47,363 ML of water.

The lakes supplying water to Mumbai include Upper Vaitarna, Modak Sagar, Tansa, Middle Vaitarna, Bhatsa, Vihar, and Tulsi. While Tulsi and Vihar are located inside Sanjay Gandhi National Park (SGNP) in Mumbai, the remaining lakes lie in Thane and Nashik districts. Over the past 24 hours, the catchment areas of these seven lakes received a cumulative 724 mm of rainfall. The India Meteorological Department had issued an orange alert for Mumbai, Thane, and neighbouring districts on Thursday.

As recently as Tuesday this week, lake levels stood in the single digits, at just 9.78 per cent (1,41,511 ML), sparking concerns over water availability in Mumbai. Earlier this week, the Brihanmumbai Municipal Corporation (BMC) clarified that no water cuts would be required and that the available stock would suffice until the end of July.