In a significant step towards upgrading Mumbai's water supply infrastructure, the Brihanmumbai Municipal Corporation (BMC) has initiated work on a 21-kilometre water conveyance tunnel linking Yevai and Kasheli in Thane to Mulund. This project, aimed at enhancing water supply to the eastern suburbs, will complement the existing pipeline network, which will be retained as a backup.

The tunnel construction, estimated to cost around Rs. 4,500 crore, will be executed in two phases. According to a civic official, the work order has been issued, and construction is set to commence within the next month. Once completed, the project will strengthen Mumbai's water distribution system, reduce the risk of leakages, and ensure a more reliable water supply.

The water tunnel from Kasheli to Mulund is expected to align with the ongoing Mumbai-Nashik highway expansion. In addition to this, the BMC will also construct a 14-km tunnel from Yevai Reservoir to Kasheli, forming a comprehensive water infrastructure network. After issuing tenders in March, the BMC has now appointed a contractor, and both tunnels are expected to be completed in six to seven years.

The decision to construct the tunnels 110 metres underground aims to reduce the risk of damage to water pipelines due to surface-level infrastructure developments. The existing pipelines are vulnerable to ruptures caused by ongoing projects in Mumbai and Thane. "By taking the water supply underground, we minimise the chances of leaks and contamination," said a BMC official.

The BMC is also considering other major tunnel projects to strengthen the city’s water supply, including potential links between Marol and Mahim, Malabar Hill and Cross Maidan, and Veravali and Yari Road, as well as a connection between Gundavili and Bhandup Complex. Additionally, smaller tunnels will connect Powai, Veravali, and Ghatkopar, further enhancing the city's water distribution network. 

Currently, the BMC supplies 3,900 million litres of water daily from lakes in Thane and Nashik through a vast pipeline system. This new tunnel project is seen as a key step in securing Mumbai’s water supply for the future.