Mumbai suburban railways plan underground tanks to stop monsoon flood disruptions
To combat the annual disruption of suburban railway services due to monsoon flooding, authorities have initiated a feasibility study for constructing underground stormwater storage tanks on railway land across Mumbai.
The project, falling under a major urban transport initiative, seeks to assess long-term solutions that can prevent track submersion and enhance operational resilience of the city’s overburdened transit system. This study, funded by an international infrastructure bank, aims to explore whether extensive underground water retention tanks can be integrated into existing railway land without hampering current operations or future expansions. The primary goal is to temporarily hold rainwater during peak rainfall periods, thereby reducing the burden on an already stretched civic drainage network and minimising the severe delays and safety risks associated with waterlogged tracks.
Despite seasonal desilting and other pre-monsoon efforts, flooding on rail tracks remains a chronic urban issue, particularly in low-lying pockets across Central, Harbour, Trans-Harbour and Western railway corridors. Submerged tracks frequently lead to cascading disruptions, including signal malfunctions, power faults, and compromised commuter safety—prompting a renewed focus on structural interventions rather than temporary fixes.
The year-long technical study will involve detailed assessments of the soil profile, urban topography, and existing stormwater evacuation systems. It will also examine how such tanks could be synchronised with broader municipal infrastructure to ensure seamless and efficient water diversion. The initiative is being positioned not merely as an engineering project but as a climate-adaptive urban design solution for a city grappling with the intensifying impacts of erratic monsoon patterns.
The idea draws conceptual strength from the successful implementation of similar tanks in the city’s low-lying zones, where massive underground reservoirs were deployed to store and later release rainwater in a controlled manner. These prior projects collectively held over 6 crore litres of water and significantly reduced flood severity in adjacent neighbourhoods last monsoon. Inspired by their effectiveness, the current study seeks to replicate and scale such infrastructure along railway lines that are most vulnerable to seasonal waterlogging.
Should the feasibility study yield favourable outcomes, it could pave the way for the rollout of a citywide underground tank system targeting multiple high-risk flood zones across the suburban network. This would mark a critical shift from short-term mitigation to permanent flood-resilience infrastructure in India’s financial capital—an urgently needed step as climate change continues to increase rainfall unpredictability.
While still in the early stages, the initiative reflects a growing consensus that urban infrastructure must evolve to meet 21st-century climate challenges. With increasing urbanisation and a changing hydrological cycle, future-proofing critical transport lifelines like the suburban railways is no longer optional but essential for ensuring equitable, sustainable and uninterrupted urban mobility.
Mumbai suburban railways plan underground tanks to stop monsoon flood disruptions
