The Brihanmumbai Municipal Corporation (BMC) has completed the final breakthrough of a 5.8-km underground sewage tunnel connecting Don Bosco School Junction in Borivali with the New Malad Pumping Station in Malvani. The achievement marks significant progress in Phase I of the civic body’s Priority Sewer Tunnel Project, which is now 90% complete and scheduled for completion by July 31, 2027.
The tunnel is designed to strengthen wastewater management across Mumbai’s western suburbs, where the existing sewer network faces pressure from rising sewage volumes. Once operational, the new infrastructure is expected to improve sewage conveyance, reduce overflow risks and support pollution-control efforts.
Tunnel Specifications and Capacity
Built using segmental lining technology, the underground tunnel has an internal diameter of 3.2 metres and a designed sewage-carrying capacity of 1,182 million litres per day (MLD). The infrastructure also comprises five shafts, three drop shafts and six screen chambers.
The project aims to address persistent overloading in the existing sewer system. Following the completion of Phase I, sewage-carrying capacity across Dahisar, Borivali, Gorai, Shimpoli and Charkop is expected to reach 1,136 MLD, easing pressure on existing pipelines and helping minimise the possibility of sewage overflows.
Lower Maintenance Costs and Pollution
The new tunnel is also expected to redirect sewage currently handled by pumping stations in Gorai, Shimpoli, Charkop and Malad. This could reduce dependence on these facilities and lower recurring expenditure on their maintenance and repairs.
Beyond improving the movement of wastewater, the project is intended to strengthen the broader sewage management network across the western suburbs. By reducing strain on existing infrastructure and improving sewage conveyance, the initiative is expected to contribute to efforts to control pollution affecting Mumbai’s rivers and coastal waters.
With the final breakthrough achieved, the project has crossed a key construction milestone. The remaining work will be crucial to bringing Phase I into operation by the BMC’s stated July 2027 deadline and delivering the intended improvements to the city’s sewage infrastructure.
Source: The Free Press Journal
