Mumbai is confronting its usual summer worry about whether the city will receive sufficient water even after monsoon rains begin. The financial capital and surrounding areas depend primarily on rainfall to fill their supply. The city draws drinking water from seven reservoirs: Bhatsa, Upper Vaitarna, Modak Sagar, Tansa, Middle Vaitarna, Tulsi and Vihar. Unlike many other large cities, Mumbai lacks a major alternative source, so a timely and adequate monsoon remains essential. Recent delays in the southwest monsoon have heightened worries. Data from the Brihanmumbai Municipal Corporation show combined live storage in the seven reservoirs has fallen below 7 percent, well under the amount recorded at the same time last year. In the corresponding period of 2025 the reservoirs held 39.5 percent of capacity. Latest figures indicate a small further drop from Sunday, when total usable water stood at 1,02,460 million litres or 7.08 percent of capacity. Among the reservoirs, Vihar and Tulsi currently hold the highest percentages. Vihar contains 12,499 million litres, equal to 45.13 percent of its capacity, while Tulsi holds 1,952 million litres or 24.26 percent. Bhatsa, a key source, has 39,636 million litres or 5.53 percent of capacity after receiving 8 mm of rain in the past day. Modak Sagar stands at 23,819 million litres or 18.47 percent, and Middle Vaitarna at 22,308 million litres or 11.53 percent. Tansa remains lowest with only 65 million litres or 0.05 percent. Upper Vaitarna is below its lower drawdown level and its usable storage is recorded as zero. Water releases from Upper Vaitarna started on June 22 and from Middle Vaitarna on June 23. Catchment areas have seen heavy rain recently. The Bhandup Complex recorded 191 mm in the past 24 hours, bringing its seasonal total to 386 mm. Tulsi received 179 mm and Vihar 112 mm in the same period. The monsoon normally arrives around June 10 but reached later this year. Last year it arrived in May. The slow start has prompted the civic body to monitor levels closely and enforce conservation steps ordered by the state water resources department.
