BMC Water Tunnel Project Advances Underground Network
The Brihanmumbai Municipal Corporation (BMC) is preparing to begin tunnel boring for one of its largest underground water infrastructure projects, marking a significant step towards strengthening Mumbai’s long-term water transmission network. Scheduled to commence by September, the Kasheli–Mulund underground corridor is designed to improve the efficiency, reliability and resilience of the city’s drinking water supply while reducing transmission losses across the distribution system. The Water Tunnel Project spans approximately 7.13 kilometres and will create a 4.5-metre-diameter underground conduit linking Kasheli in neighbouring Bhiwandi with Mulund. Construction began in September 2024, with the project targeted for completion by October 2030. Once operational, the tunnel will serve as an additional transmission route carrying water from the Bhatsa reservoir system into Mumbai, providing greater operational flexibility for the city’s expanding population.
Municipal officials recently reviewed progress at both construction sites, where preparatory civil works have reached advanced stages ahead of tunnel excavation. At the Mulund end, the deep launching shaft required for the Tunnel Boring Machine (TBM) has been completed, along with associated assembly and access tunnels. Reinforced concrete lining work is now progressing to prepare the shaft for the commencement of underground excavation. Meanwhile, work continues at the Kasheli site, where a recovery shaft is being excavated to facilitate retrieval of the TBM after completion of tunnelling. Civic engineers have also confirmed that all major TBM components and the conveyor system needed to transport excavated material have arrived at the project location, indicating that the project is moving into its principal construction phase. The Water Tunnel Project forms part of Mumbai’s broader strategy to modernise ageing water infrastructure and minimise losses during transmission. Urban water specialists note that underground conveyance systems offer greater protection from surface disruptions, reduce maintenance requirements and improve the resilience of critical utility networks against extreme weather events and expanding urban development. As climate variability increases pressure on water resources, strengthening transmission efficiency has become an important element of sustainable urban water management.
Alongside the drinking water corridor, the civic administration is also advancing a parallel programme to expand treated wastewater reuse. Preparatory work continues on dedicated underground tunnels that will transport tertiary-treated wastewater between treatment facilities and strategic distribution points. Tunnel boring for the proposed 11.61-kilometre Ghatkopar–Bhandup wastewater tunnel is expected to begin in early 2027, supporting efforts to reduce dependence on potable water for industrial and non-potable applications. Urban planners believe these twin investments reflect a gradual shift towards integrated water infrastructure, where both supply augmentation and wastewater recycling contribute to long-term resource security. Diversifying transmission routes while expanding recycled water networks could improve operational resilience and support more sustainable management of Mumbai’s finite freshwater resources.
As excavation prepares to begin later this year, the success of the Water Tunnel Project will depend not only on engineering execution but also on maintaining safety, construction quality and timely delivery. Once completed, the underground corridor is expected to play a central role in strengthening Mumbai’s water security while supporting the city’s future growth in a changing climate.
