Chennai: Chief minister C Joseph Vijay on Wednesday laid the foundation stone for a ₹3,108.55 crore ring main pipeline project, a circular water infrastructure network expected to transform water distributed across the city.The project, to be implemented by Metrowater with financial assistance from Asian Development Bank (ADB), aims to ensure uninterrupted drinking water supply across Chennai by connecting water treatment plants, desalination plants and distribution stations. This will allow water to be redirected to areas affected by disruptions at individual treatment plants or water sources.Now, treatment plants supply water to designated parts of the city through dedicated trunk mains. The city lacks an interconnected network. The ring main system is expected to address this gap by linking nine treatment and desalination plants, including the 400 million litres per day (mld) desalination plant under construction at Perur.The project involves laying 91.2km of new ring main pipelines, 64.2km of transmission pipelines and 2.65km of pumping mains. The ring main will extend 97.9km, including existing pipelines, with pipe diameters ranging from 1,200mm to 2,000mm.The project also includes seven new underground tanks, replacement of pumps at seven clear water pumping stations and construction of eight surge tanks. These facilities will improve storage, pumping and pressure management across the network. Metrowater officials said a ‘supervisory control and data acquisition’ (SCADA) system will be installed to monitor water flow, pressure and quality in real time.Metrowater now supplies about 1,260mld of drinking water to Chennai’s approximately 91 lakh residents through a network of 143 distribution stations.The ring main project was announced in the Tamil Nadu budget for 2025-26, with an initial allocation of ₹2,423 crore. Its scope and estimated cost have since been revised.
