A holistic approach for lake restoration

CHENNAI : Based on the preliminary findings of the hydrological survey by IIT Madras, the restoration of the Sembakkam lake is set to get holistic focus. “Usually when it comes to lake restoration,  only the lake area is looked at; we are planning to look at other aspects including cleaning the inflow and outflow canals to the lake,” said Jayshree Vencatesan, managing trustee of Care Earth Trust.

A second round of meeting with the residents regarding lake restoration was carried out by Care Earth Trust and The Nature Conservancy organisations, who have taken up the restoration work. It will be carried out with research support from IIT Madras.  “The study will go on for another two months. But, based on its preliminary findings, the desilting work will be carried out, alongside strengthening of bunds,” said M Nisha Priya, project manager of the Nature Conservancy Centre.

Among the first areas of intervention, along with cleaning the inflow and outflow canals would be to allow native plant species to thrive by removing the invasive ones. One of the main objectives of the project is the conservation of the Pallikaranai marshlands, one of the last remaining freshwater marsh, using a watershed basin approach. “We are looking at restoring the damaged lakes that drain into the Pallikaranai marshland; Sembakkam is one such lake,” said Nisha.

The organisations are looking at interacting with residents, holding stakeholder discussions regularly. Residents who attended the meeting, mostly comprising resident welfare associations in Sembakkam and surrounding areas, raised two issues — dumping of solid waste in the lake and the absence of an underground drainage system. “Our main request was for sustainable maintenance of the lake. For that, underground drainage system is important,” said Ramakrishnan of Sri Sarvamangala Nagar Residents Association, Chitlapakkam. “But if underground drainage is introduced, steps must also be taken to treat sewage before it is let into the lake which is not the case in many nearby municipalities that have underground drainage system,” he added.

Residents said better management of the lake would have meant averting the drinking water crisis that is now plaguing many of the southern suburbs. They also complained of dropping ground water levels. About 10 years ago, groundwater was available even at four feet. Now, however, they said, the levels have dropped to as much as 300 feet.

First step
Among the first areas of intervention, along with cleaning the inflow and outflow canals would be to allow native plant species to thrive by removing the invasive ones.