More than 10 years after the idea was conceived, the Brihanmumbai Municipal Corporation last week floated a Rs 3,000-crore tender to construct a dam on the Gargai river located in Palghar district within
the Mumbai Metropolitan Region (MMR). The Gargai dam, according to reports, will be the first dam the BMC will construct for water supply within Mumbai’s city and suburban region.
The Gargai dam
The Gargai River is a tributary of the Vaitarna River, located in Palghar district in the Mumbai Metropolitan Region.
It is designed to be a 69-metre high roller-compacted concrete (RCC) dam.
The tunnel vision: Why it matters
A 1.6 km tunnel (about 2.2 m in diameter) will be built to connect the reservoir on Gargai to the existing Modak Sagar reservoir, enabling the water to be supplied into Mumbai’s system.
This tunnel will be boring through the hillock between the new Gargai reservoir and the existing Modak Sagar reservoir.
The tunnel is a water transfer conduit, essentially an underground pipe/tunnel that moves water by gravity (and possibly assisted by pressure), from one reservoir to another.
It’s built so that the water collected behind the Gargai dam can be sent directly into the Modak Sagar reservoir system, which already feeds Mumbai’s city water supply.
Eighth sources of water: How it will help
Once completed, the project is expected to add about 440-450 million litres per day (MLD) of potable water to Mumbai’s supply — making it a key eighth water source for the city’s network. Mumbai.Live+1
How much will it cost? When will Gargai dam be ready?
The estimated cost is around Rs 3,000-3,040 crore.
Tendering has begun but full construction is planned over several years, with targeted completion around 2029.
The project requires forest and wildlife approvals because it lies partly within Tansa Wildlife Sanctuary and will impact significant forest land.
Will it affect locals?
Completion will flood portions of forest and agricultural land. Two villages (Ogda and Khodada) would be fully submerged, and parts of others (Pachghar, Tilmal, Phanasgaon, Amle) affected.
Affected families are planned to be relocated, and compensatory afforestation is proposed elsewhere to offset environmental loss.
