Chennai To Get Its Fourth Desalination Plant As Metro Water Picks Va Tech Wabag To Build 400 MLD Project At Rs 4400 Crores

VA Tech Wabag Ltd, a Chennai-headquartered water technology focussed on municipal and industrial users, has bagged an order from Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) for building a 400 million litres per day (MLD) desalination plant at a total cost of about Rs.4,400 crore.

The reverse osmosis technology-based desalination plant will be executed on a design, build, and operate (DBO) model. The plant is likely to come up at Perur village in East Coast Road.

WABAG will execute the project in a joint venture with Metito Overseas Ltd. Once completed, the project will be the largest desalination plant in the South East Asian Region.

The desalination plant project will be funded by Japan International Cooperation Agency (JICA) and seeks to improve Chennai's water security through a stable source of drinking water.

Once the project is complete, Chennai can treat about 750 MLD of desalinated water.

Tamil Nadu has been the pioneer in the use of desalination technology for providing potable water and achieving water security. It already has two fully functional desalination plants near Chennai - Minjur and Nemmeli.

Minjur, the first desalination plant in India, was opened in 2010. The 60-acre plant is located in Katupalli village in North Chennai. The plant has a capacity of 100 MLD.

Besides providing clean water to over half a million city residents, the water from the Minjur desalination plant is supplied for industrial purposes such as the Ennore Port Trust and North Chennai thermal power plant.

The plant produces potable water using reverse osmosis (RO) technology. A 33km pipeline constructed by CMWSSB carries the treated fresh water from Minjur to Red Hills.

Minjur desalination project was executed on a design, build, own, operate and transfer (DBOOT) basis by Chennai Water Desalination Limited (CWDL). CWDLwas set up as a special-purpose vehicle established by a consortium comprising IVRCL Infrastructure and Projects and Befesa Agua. IVRCL holds 75% and Befesa a 25% stake in CWDL.

Chennai's second desalination plant is located at Nemmeli on East Coast Road and has been functional since 2013. It can treat 100 MLD of seawater a day.

Owned by Chennai Metrowater, the plant was constructed by VA Tech Wabag as a part of a consortium with IDE Technologies in Israel and Larsen and Toubro (L&T) Limited.

A 65-km-long pipeline from the Nemmeli plant connects various parts of the city with many underground sumps en route.

The third desalination plant is also coming up at Nemmeli and will be ready before the end of 2023. The third plant would be able to treat 150 MLD of seawater daily. 

Work on building a 49-km-long pipeline to supply treated water from this plant to nearly nine lakh city residents is underway. Water from the upcoming plant would provide drinking water to Madipakkam, Velachery, Alandur, Medavakkam, Nanmangalam, St. Thomas Mount, and the IT corridor areas. 

Chennai's chronic water problem

Chennai suffers from a chronic water problem as the city depends extensively on groundwater, replenished by an average rainfall of 1,276mm.

The city receives about 985mld of water from ground and surface water sources, against the demand of 1200mld. The demand is estimated to increase to about 2,700mld by 2031.

In the early 2000s, the state government decided to alleviate the freshwater problems by desalinating sea water.