The Brihanmumbai Municipal Corporation (BMC) has received Coastal Regulatory Zone (CRZ) approval for an 8.48-km tunnel to carry tertiary-treated water from the Dharavi Wastewater Treatment Facility to the Bhandup Water Filtration Plant via the Ghatkopar STP. Construction of the 2.7-metre-diameter tunnel, estimated at Rs 3,000 crore, is set to begin.
The project is part of a Rs 27,309-crore upgrade of seven sewage treatment plants in Mumbai, aiming to treat 2,464 million litres per day (MLD) of sewage—half via secondary treatment and half to tertiary standards. The tunnel, running at depths of 145–152 metres, is designed to transport 416 MLD of treated water, which could help meet the city’s future potable water demand.
Mumbai’s seven STPs—Worli, Bandra, Malad, Ghatkopar, Dharavi, Bhandup, and Versova—treat a combined 2,464 MLD, while the city receives 3,850–4,000 MLD of water daily against a demand of around 4,500 MLD. Officials noted that 34% of water is lost as non-revenue water due to leakages, theft, and pilferage, and that reusing treated water, even for non-potable purposes, would be beneficial.
