Mumbai Water Infrastructure Enters New Climate Era
Mumbai is preparing to diversify its drinking water sources with the state’s first large-scale seawater desalination facility, signalling a strategic shift from almost complete dependence on monsoon-fed reservoirs towards a more climate-resilient urban water system. The proposed project at Manori in the city’s north-western suburbs is expected to strengthen long-term water security as population growth, redevelopment and climate uncertainty place mounting pressure on existing supplies. The Mumbai desalination plant is planned to ultimately generate 400 million litres of potable water each day, with the first 200 million litres per day (MLD) targeted for commissioning by 2029. Civic authorities intend to begin full-scale construction after the monsoon, following the completion of key coastal and environmental approvals.
Mumbai currently draws nearly all of its drinking water from seven reservoirs located across Thane, Palghar and Nashik districts. While seasonal rainfall has traditionally replenished these lakes, changing rainfall patterns and rising urban demand have increasingly exposed the limitations of relying almost entirely on monsoon-dependent sources. During this year’s summer, declining reservoir levels prompted phased water conservation measures, highlighting the vulnerability of the city’s existing supply network before monsoon inflows restored storage levels. Urban planners note that future demand is likely to increase as redevelopment projects replace low-rise buildings with higher-density residential complexes, alongside continued commercial expansion and population growth. Municipal estimates indicate that the city’s daily demand already exceeds available supply, creating a structural gap that alternative water sources will need to address over the coming decades. The Mumbai desalination plant will use reverse osmosis technology to remove salt and impurities from Arabian Sea water before supplying treated drinking water to the municipal network. Although desalination has become an established component of water infrastructure in countries such as Israel, Singapore, Australia and several Gulf nations, the technology remains relatively new in Maharashtra’s urban water sector.
Environmental safeguards will play a central role in the project’s implementation. Regulatory approvals require continuous monitoring of marine ecosystems, careful management of concentrated brine discharge, protection of nearby mangrove habitats and tidal flows, and the use of underground tunnelling for offshore pipelines to minimise ecological disturbance. Authorities have also been directed to integrate renewable energy into plant operations to reduce the facility’s carbon footprint, recognising that desalination is generally more energy-intensive than conventional reservoir-based water supply. The Manori project forms part of a broader strategy to diversify Mumbai’s future water portfolio. Alongside the proposed desalination facility, civic authorities are advancing plans for the Gargai dam while evaluating a second desalination project at Versova. Together, these initiatives are intended to reduce dependence on seasonal rainfall and build greater resilience against climate variability.
As Mumbai’s urban footprint continues to expand, water experts emphasise that infrastructure investments alone will not secure long-term sustainability. Reducing distribution losses, improving wastewater recycling, promoting efficient water use and protecting natural catchments will remain equally important in creating a resilient and equitable water system capable of supporting the city’s future growth.
