The Chennai Metropolitan Water Supply and Sewerage Board (Metro Water) has floated tenders to upgrade the underground sewer network in several parts of the city at an estimated cost of ₹800 crore.
The project will cover the Adyar, Teynampet and Kodambakkam zones and aims to modernise the ageing sewer infrastructure. Officials said the initiative will help replace old pipelines, reduce sewer blockages and prevent road cave-ins that often occur due to damaged underground lines.
As part of the project, new cast iron (CI) and ductile iron (DI) pipelines will be installed to strengthen the sewer network. In addition, sewage pumping stations will be upgraded, and odour control systems along with real-time monitoring facilities will be set up to improve the overall functioning of the sewer system.
The project will be funded by the Asian Development Bank and will initially begin in the Nesapakkam Sewage Treatment Plant (STP) catchment area.
According to officials, the infrastructure upgrade is expected to enhance sewage management and reduce disruptions caused by pipeline failures in the covered zones. The entire project is planned to be completed within two years.

