CHENNAI: The Water Resources Department (WRD) is planning to convert a few lakes in the city and suburbs into drinking water sources. According to a senior official, Chennai, as of now, needs 20,000 million cubic feet (tmcft) of water a year. The reservoirs Poondi, Cholavaram, Red Hills (Puzhal lake), Chembarambakkam, Veeranam, and Thervoy Kandigai can store only 13.213 tmcft. The city’s water requirements, however, might rise to 25 tmcft a year.
To supplement the water supply, a small reservoir was built by upgrading Kattur and Thatmanji tanks by increasing their combined capacity from 58.27 million cubic feet (mcft) to 350 mcft. “This would also benefit 5,804 acres of ayacut land,” he added. Chengalpattu’s Kolavoy lake would also be converted into a drinking water source. It’s capacity has been proposed to be increased from 330 mcft to 650 mcft. Also, there was a plan to establish surplus courses near Porur and Nemam.
Professor S Janakarajan, president of, South Asia Consortium for Inter-Disciplinary Water Resources Studies, told TNIE that the only way to save rainwater was to convert lakes as reservoirs. “Ninety per cent of rainwater goes to the sea. According to the old map, there were 3,600 tanks in Chennai, Tiruvallur, Kancheepuram and Chengalpattu districts.
Now, however, the WRD maintains only a few tanks. It’s possible to prevent floods and store rainwater if these tanks are identified and restored,” he said. He said the city now depended on Krishna water from Andhra Pradesh. If, however, the city enhanced its rainwater storage capacity, it could end this dependence.