Mumbai is moving closer to integrating desalinated seawater into its municipal distribution network with a proposal to construct a 7.2-kilometre underground tunnel linking the city’s first desalination facility at Manori to western suburban water infrastructure. The project represents a significant investment in long-term water security as the metropolis seeks to diversify supplies beyond its rain-dependent reservoir system amid increasing climate uncertainty. A proposal scheduled for consideration by the civic standing committee seeks approval to award the engineering, construction and operational contract for the transmission system. The underground corridor forms a major component of Mumbai’s broader desalination initiative, with the tunnel and associated infrastructure accounting for a substantial share of the overall project investment.
According to project documents, the Desalination Water Tunnel will extend approximately 4.6 kilometres between Manori and Charkop before continuing another 2.6 kilometres to Mahavir Nagar in Kandivli. The tunnel is planned at depths ranging from around 104 to 128 metres below ground and will be excavated simultaneously from both ends using tunnel boring machines to accelerate construction while minimising disruption at the surface. The proposed infrastructure extends beyond the underground passage. It includes deep access shafts at Manori, Charkop and Mahavir Nagar, a high-capacity pumping station, transmission pipelines, treated water storage reservoirs, valve chambers and a Supervisory Control and Data Acquisition (SCADA) system for real-time monitoring and operational control. While the pumping station has been designed for an ultimate capacity of 400 million litres per day (MLD), the first phase will initially support 200 MLD, matching the output planned for the desalination plant’s initial stage. Municipal officials believe the Desalination Water Tunnel will improve network efficiency by enabling treated seawater to serve the western suburbs, allowing water currently transported from conventional treatment facilities to be redistributed to other parts of Mumbai.
Such operational flexibility is expected to optimise existing infrastructure while helping address rising urban demand without immediate dependence on additional freshwater sources. The proposal also includes a public consultation process, with civic authorities inviting objections and suggestions from property owners and residents located along the tunnel alignment before construction begins. Subject to statutory approvals, work is expected to commence in the coming weeks, with completion targeted within 45 months. Urban water specialists say the project reflects a broader transition in coastal cities towards climate-resilient water infrastructure. Mumbai currently faces a gap between daily demand and available supply, a challenge that becomes more pronounced during periods of erratic monsoon rainfall. While desalination is energy-intensive and requires careful environmental management, experts view it as one component of a diversified water strategy that should also prioritise demand management, wastewater recycling, leak reduction and watershed conservation.
As Mumbai’s population and economic activity continue to expand, strengthening water resilience will require balancing large-scale engineering investments with sustainable resource management. The success of the project will ultimately depend not only on timely construction but also on its integration into a broader urban water strategy capable of supporting future growth while reducing climate-related risks.
