Mumbai : A significant milestone was achieved on Tuesday as the first phase of the sewage tunnel under the Mithi River rejuvenation project was successfully completed at Kurla Gardens.
The entire length of the tunnel spans 6.70 km, with the initial phase covering a distance of 1.835 km. This crucial infrastructure will serve as a conduit for transporting contaminated water from two nullahs to the sewage treatment plant located in Dharavi. By effectively cleansing the river water, this project aims to restore the environmental equilibrium and promote a healthier ecosystem.
Smallest sewage tunnel in India
It is also the smallest sewage tunnel in India, with an internal diameter of 2.60 meters and an external diameter of 3.20 meters. The tunnel is being constructed with a segmental lining method using earth pressure balance tunnel boring machines. The boring for the first of the three phases of the tunnel started at Dharavi Sewage Treatment Plant on November 14, 2022, and was completed on Tuesday afternoon.
Second phase
Under the second phase, the boring of 1.80 km of the underground tunnel will start from Kurla Garden and will be completed at SCLR Junction Shaft, Sahar-Kurla Road on LBS Road.
Third phase
In the third and final phase, a 3.10 km long tunnel will be dug from the SCLR junction shaft to Bapat Nalla. Around 43% of the project has been completed and is expected to be completed by September 30, 2025. An estimated 168 million litres of contaminated water per day going into rivers from Bapat Nullah and Safed Pul Nullah will be carried through this tunnel to the sewage treatment plant in Dharavi. The sewage will be treated there and released into the creek at Mahim Nature Park. The total carrying capacity of the tunnel is 400 million litres per day, which will currently carry 168 million litres of dry weather flow per day.
