Vihar and Tulsi Lakes began overflowing on 7 July 2026 after heavy monsoon rainfall, affecting Mumbai’s seven-lake reservoir network and prompting monitoring of downstream river levels.
Reservoir network and hydrology
- Administrative limits: Vihar and Tulsi are the only two lakes within Brihanmumbai Municipal Corporation limits and form part of the seven-lake system supplying Mumbai.
- Drainage linkage: Overflow from Tulsi and Vihar discharges into the Mithi River.
Capacities, supply and overflow timing
- Tulsi Lake capacity: Usable storage 8,046 million litres; supplies about 18 million litres per day (MLD).
- Vihar Lake capacity: Storage 27,698 million litres; supplies about 90 MLD.
- Overflow timings (7 Jul 2026): Vihar at 21:00 hrs; Tulsi at 23:43 hrs.
- Seasonality note: Tulsi overflow in 2026 occurred earlier than 16 Aug 2025 and 4 Aug 2024.
Current storage metric
- Aggregate stock (8 Jul 2026): Combined live storage across all seven lakes was 41.43% of total capacity.
Meteorological forecast and hazards
- IMD advisory (8 Jul 2026): Heavy to very heavy rainfall with winds of 60–70 km/h forecast for Mumbai, Thane, Palghar, Raigad and the Konkan; warnings include localized flooding, landslides and transport disruption.
IASPOINT Booster Facts
- Seven-lake system: Operational resilience of Mumbai’s supply depends on cumulative live storage across the seven reservoirs.
- MLD unit: MLD denotes million litres per day, commonly used in urban water supply planning and demand estimates.