A collaborative effort of Environmentalist Foundation of India, Corporation and local residents

Several smaller waterbodies in the western and southern suburbs, which were neglected and considered almost non-existent in the city map, have been brought back to life this monsoon.

Thangal eri, beneath the Chennai Bypass Road near Kathirvedu, on the western suburbs, presents a classic example. Until a few months ago, it was covered with invasive weeds and construction debris, and was slowly eaten up by encroachments.

The 11-acre waterbody now has an identity, as the Environmentalist Foundation of India, a voluntary organisation, has restored it with the support of the Greater Chennai Corporation and community participation. This is one of the 37 waterbodies rejuvenated and ready for monsoon rains this year.

As this lake, a buffer source between the Red Hills and Korattur lakes, was neglected, several residential areas suffered local flooding. The waterbody lost its storage capacity, and floodwater spilled over to nearby areas, said J. Rammohan, a resident of Kadirvedu.

In five months, the EFI deepened the lake by 3 ft, formed recharge pits and constructed a bund with the silt that was removed. G. Sanjay Prasad, environmental engineer, EFI, said: “We have also created G-shaped nesting islands for reptiles and birds. A check bund, that acts as a check dam to enhance the water-holding capacity, has been formed inside the lake.”

Similarly, the two-acre Madhanankuppam pond, that was passed for vacant land until a few months ago, now has water lilies, that grow only in freshwater. Nearly three truckloads of trash was removed from the lake, and it was deepened. The pond restoration will help recharge groundwater for a radius of 2 km and the space will also act as a home to Indian flapshell turtles.

“We are developing these waterbodies as ecological habitats and not recreational spaces. These will also act as flood-mitigation sources,” Mr. Prasad said. The EFI has adopted different restoration techniques, suited for various lakes, including in Thoraipakkam, Akkarai and Velachery. These waterbodies, chosen based on Corporation records, will have native plants and will be fenced.

Unique challenges

Arun Krishnamurthy, founder, EFI, said each waterbody posed a unique challenge. In the Thirumangai Alwar pond, Sriperumbudur, sludge management was a major issue and in the 6-acre Alleri lake, Tambaram, 10 intermediate bunds were formed to treat polluted water that flows into it.

Ponds are critical to arrest local flooding. They act as recharge points in neighbourhoods, especially where borewells are rampant.

“These waterbodies will turn the city into a habitat for all living organisms. We need to create water literacy among more residents,” he said. Read more