The city’s only freshwater body, the Pallikaranai marshland, is under threat. Not from anyone else, but from the government and its development plans, environmentalists charge.
The storm water drain being built to prevent flooding in Velachery and nearby residential colonies during the monsoon season could sound a death-knell for the marshland, the feeding ground for several thousands of migratory birds during winters.
According to environmentalists and forest officials, the sustenance of the marshland depends on the flood waters received from the Velachery lake. It could become parched, once the drainage channel, being constructed on Taramani Link Road, was completed and linked to the South Buckingham Canal to drain out the surplus water from the lake into the sea.
Earlier, excess rainwater flowed into the marshland from over 31 tanks before draining out into the Okkiyam Madavu and then joining the sea. Once the diversion channel was completed, the rainwater would directly flow into the sea, say activists.
KVRK Thirunaranan, founder, The Nature Trust, said the wetland filled with water and grass throughout the year had already shown symptoms of drying on the northern side of the Thoraipakkam-Pallavaram Radial Road. “It is unusual for the marshland to be dry during this time of the year. With most of the waterbodies around the vanishing due to encroachments, the Velachery lake is the only source of water for the marshland,” he points out. Government agencies knew about the threat to the marshland for a long time. According to senior forest officials, the serious consequences of the project to divert rainwater from the Velachery lake were driven home to the officials of the PWD’s Water Resources Department in the initial stages of the project itself.
However, WRD officials say the project was recommended by the Chennai Corporation as part of the improvement of macro and micro drains of the city. The channel will be operated only during floods.
Claiming that the Pallikaranai marshland would be overloaded with surplus water from several waterbodies, WRD officials say that the 4-km diversion channel was being constructed to alleviate flooding in the neighbourhood such as Vijaya Nagar and Seethapathy Nagar.
“We have made arrangements to regulate water flow in the concrete channel to send water to the Pallikaranai marshland whenever needed,” an official said, claiming that there was no threat to the marshland.
