Water bodies, big or small, assume great importance as sources of storage and groundwater recharge — but they are also easy prey for abuse. Three such long-neglected lakes will be rejuvenated next month, with the State government proposing to turn them into drinking water sources to meet the growing demands of the expanded city.
The sprawling water body in Nemam near Thirumazhisai is one among the lakes to be improved for additional storage. The water bodies in Ayanambakkam near Ambattur and Porur would also be improved at a total cost of Rs.130 crore.
With a water spread area of over 750 acre, Nemam lake is located upstream of Chembarampakkam reservoir, one of the predominant drinking water sources for Chennai. Unlike many other water bodies around the city, the lake to a large extent has been spared of encroachment. However, it has its share of problems.
Sudha Sureshkumar, a resident of Nemam, said, “Many families like mine in Nemam and Kuthambakkam villages are dependent on the lake for irrigation needs. We cultivate paddy. The lake brims with water through the year except during peak summer. I use groundwater from my well for drinking.”
Residents of Nemam complained that dumping of sewage in the lake and illegal sand mining was rampant. Welcoming the Water Resources Department's decision to increase the storage capacity from 257 million cubic feet (mcft) to 577 mcft, they said that the department must initiate measures to protect the lake from further abuse.
The storage of Cholavaram reservoir would also be considerably increased. This would add nearly 600 mcft, which is equal to three weeks of water supply to Chennai at the rate of 816 million litres a day. A WRD official said, “We have to acquire lands for formation of a surplus channel of Nemam lake. It would be used to store and transmit Krishna water to Chembarampakkam reservoir. Tenders have been floated and work is expected to start mid-April. The project period permits us to carry on work for 18 months. But we want to complete work by this October in Nemam and Ayanambakkam lakes.”
The works will include desilting, deepening of the lake bed, strengthening of the bund, and reconstruction of the weir — a structure through which surplus water flows out. The sale of nearly 60 lakh cubic metre of soil excavated from these lakes is expected to cover part of the project cost. Residents of Porur said that the government must also take steps to protect the water bodies and their surplus courses from encroachments.