In six months, three neighbourhood lakes will supply 30 million litres of water a day of water to meet Chennai’s water demand.

Work is on to conduct soil tests simultaneously to facilitate construction of modular water treatment plants along Ayanambakkam, Retteri and Perumbakkam lakes, Chennai Metrowater officials said.

The ₹53-crore project aims to draw a total of 30 mld of water and supply various parts of the city through the existing network. For instance, water drawn from Retteri lake would be conveyed to the nearest Kolathur distribution station for supply.

Metrowater officials said the physical work of the treatment plant would start in June and be completed by the year-end. Each of the facilities will have the capacity to treat 10 mld. Among the three lakes, the water quality in Perumbakkam lake was found to be better. Though E.coli bacteria were found in the other two lakes, they were within treatable limits. Water drawn from the lakes would be treated to provide drinking water with a total dissolved solids level less than 500 mg per litre.

IIT-M support

The project is being taken up with the support of IIT Madras for both testing the water quality and designing the plant. In a bid to address the issue of sewage flowing into the lakes, the water agency has also planned to provide constructed wetlands close to the bund, which would use vegetation and soil to treat the sewage.

The lakes have the potential to supply water for a minimum of six months, an official said.

Work to lay a 13-km-long pipeline to transport water from abandoned quarries in Erumaiyur to Chembarambakkam treatment plant would begin in June.

While welcoming the move, residents of Retteri demanded that the project to beautify Retteri must be expedited as a portion of the waterbody was covered with vegetation. M. Ravikumar, a resident, said garbage was being dumped along parts of Red Hills Road.