CHENNAI: Rampant encroachment, tonnes of garbage and unbearable stench —three issues that connect Chennai’s canals, lakes and other waterbodies. Recently, the Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) announced that it plans to construct a decentralised water treatment plant near Perumbakkam lake to meet drinking water requirement, primarily in Sholinganallur and its vicinity.
“Spread across 450 acres, Perumbakkam lake is the biggest lake in Tambaram Taluk. One of its major advantages is that the area between Chengelpet Bypass and Mambakkam is covered with dense forest and is located in proximity to the lake. As it witnesses more rains, the lake usually gets a lot of water each monsoon,” said V Subramani, founder of Sabari Green Foundation, an NGO for rejuvenation of water bodies.
However, locals and activists now rue that the lake has not been desilted for decades, polluted by numerous factors and the holding capacity has come down drastically. “If the lake is at least desilted up to 3 metres, the lake will give surplus water for city’s secondary requirement. Also, the desilting won’t cost the government anything as they already have the equipment and in turn, it will fetch them some money as they can sell the silt,” said L Balachandran, an activist working on conservation of water bodies.
Explaining the importance of desilting, P Subramaniam, a water expert said, “If there is silt, the depth of the water bodies will reduce and the capacity of the water bodies will also go down.
So, in a pond or a lake, in order to maximise storage and water carrying capacity, desilting is carried out. Secondly, it also mitigates flooding. When the carrying capacity of the water increases, the incidences of flood will reduce .”When contacted, an official from the Metro Water department said that desilting work is usually done by the Public Works Department. Officials of PWD could not be reached.
Dumping garbage, letting sewage in illegally
CMWSSB only concentrates on drawing water and supplying it, but never on the quality and maintenance of the water body, said L Balachandran, an activist. So, like most other lakes, even at Perumbakkam lake, locals let sewage into the water body.