BMC Approves ₹98 Lakh Modak Sagar Dam Repair

City's Water Reserves Continue to Shrink Despite Rainfall

Mumbai is facing growing pressure on its water supply as the city's reservoir levels have dropped to just 6.75% of total storage capacity, even after recent rainfall. The limited rain over the past few days has provided little relief because the major catchment areas that feed Mumbai's lakes received very little precipitation.

According to the latest civic data, the seven reservoirs supplying water to Mumbai now hold 97,666 million litres (ML) of water, raising concerns about water availability in the coming weeks if monsoon rainfall does not improve.

BMC Approves ₹98 Lakh for Urgent Modak Sagar Dam Repairs

Adding to the city's water challenges, the Brihanmumbai Municipal Corporation (BMC) has approved ₹98 lakh to carry out urgent repairs at the Modak Sagar Dam after engineers detected continuous water leakage.

Officials traced the problem to damaged rubber seals installed on four of the dam's eight automatic flood control gates. Over time, the seals have worn out due to age and constant exposure to weather, allowing water to leak through the gates.

The damaged seals were last replaced in 2018, and civic authorities have now begun the process of replacing them to prevent further water loss.

Leakage First Identified During Last Monsoon

The leakage issue was first noticed during the previous monsoon season when Modak Sagar was overflowing. Inspections conducted before and after the monsoon by the Dam Safety Organization recommended immediate replacement of the ageing rubber seals to maintain the dam's safety and reduce unnecessary water loss.

The approved repair work aims to strengthen the dam's operational efficiency before reservoir levels improve with the ongoing monsoon.

Why Modak Sagar Is Important for Mumbai's Water Supply

Mumbai receives nearly 3,950 ML of drinking water every day from seven major reservoirs:

• Upper Vaitarna
• Modak Sagar
• Tansa
• Middle Vaitarna
• Bhatsa
• Vihar
• Tulsi

Among them, Modak Sagar supplies around 440 ML of water daily. It also serves as an important balancing reservoir by receiving water from both Upper Vaitarna and Middle Vaitarna before distributing it across Mumbai's water network.

Commissioned in 1954, the Modak Sagar Dam is located about 120 kilometers from Mumbai in a forested region. The structure is 570 meters long, 82 meters high, and has a gross storage capacity of approximately 205 million cubic meters, making it one of the city's key water infrastructure assets.

Two Major Reservoirs Have Reached Dead Storage

The latest reservoir data shows that Upper Vaitarna and Tansa have already entered dead storage, meaning the water remaining is below the level that can normally be supplied without special pumping arrangements.

Current storage levels in the remaining reservoirs are:

• Bhatsa: 37,397 ML
• Modak Sagar: 23,314 ML
• Middle Vaitarna: 22,351 ML
• Vihar: 12,635 ML
• Tulsi: 1,968 ML

These figures highlight the increasing dependence on the remaining operational reservoirs until monsoon inflows improve.

Additional Water Cut Under Consideration

Mumbai is already operating under a 10% water supply reduction introduced by the BMC to conserve available reserves.

However, officials are now reviewing the situation and may introduce an additional 5% water cut if reservoir inflows remain below expectations over the next several days. Based on current consumption patterns, existing water reserves are expected to last only until around August 20, making steady monsoon rainfall essential for improving storage levels.

Monsoon Rain Will Be Key to Restoring Water Security

Water experts note that rainfall within Mumbai alone cannot significantly improve the city's water supply. The most critical factor is sustained rainfall across the reservoir catchment areas in Thane and Nashik, where the seven lakes receive their inflows.

Until those regions receive consistent monsoon showers, Mumbai's water reserves are likely to remain under pressure. Alongside emergency infrastructure repairs at Modak Sagar, civic authorities continue to closely monitor reservoir levels and prepare contingency measures to manage the city's water demand throughout the remainder of the monsoon season.