The number of underground drainage (UGD) projects currently on the city’s outskirts is having an adverse effect on the water bodies and canals there, residents and environmentalists have cautioned.
This is a serious problem residents living in certain interior areas of the city are familiar with. The Cooum and Adyar rivers and Buckingham Canal — the principal waterways of Chennai —have been polluted for long due to sewage inflow.
People living in village panchayats around Avadi municipality have come together to raise their voice against a drainage project that is likely to be commissioned soon. They fear that the sewer network will affect the Cooum river, which is relatively free from pollution and supports farming, an important source of livelihood in many villages. The future of this section of Cooum however looks murky, they say.
A. Elangovan, president, Kannapalayam panchayat, alleges that even before the commissioning of the underground drainage project, the municipality has been letting untreated raw sewage into the Cooum near the check-dam in their village, polluting the groundwater table.
A committee comprising representatives from six panchayats — Thirumanam, Sithukadu, Karunakarachery, Soranchery, Annambedu and Kannapalayam — have been requesting the municipality to shift the sewage let-out point at the Cooum river, currently at Paruthipattu overbridge 500 metres away, so that the upstream basin could be protected from pollution.
The committee has also strongly opposed the proposal of the Thirumazhisai municipality to let ‘treated’ sewage into the Cooum at Anaikattuchery.
G. Mugundhan, convenor, Unpolluted Cooum River Protection Committee, said it did not make any sense to route the sewage pipeline to Cooum when a sewage treatment plant was already located on the Chennai-Bengaluru Highway near Thiruverkadu. By linking the sewers to the existing STP, eight km of the Cooum river could be saved from pollution.
Sewage discharge sullies lakes in southern suburbs
A network of waterbodies in the southern suburbs, including Chitlapakkam, Sembakkam, Nanmangalam, Keelkattalai and Kadaperi lakes, are getting polluted due to discharge of sewage and industrial effluents into them.
Local bodies in these regions remain mute spectators, citing the fact that these lakes do not come under their purview.
Members of Sri Sarvamangala Nagar Residents’ Welfare Association, Chitlapakkam, have complained of sewage being let into the Sembakkam lake by three localities around it. These areas, ironically, depend heavily on this lake to maintain a healthy water table.
Association members have also drawn attention to the issue of discharge of sewage into lakes through storm water drains. The residents have requested the Public Works Department (PWD) to take steps to close the sewage outlets.
However, officials of Sembakkam municipality have denied any discharge of sewage water into the Sembakkam lake. Activist P. Viswanathan says execution of a well-planned and integrated underground drainage system for all the local bodies in the southern suburbs alone will solve the problem of lakes being contaminated owing to sewage inflow. At present, Tambaram and Pallavaram are executing underground drainage projects.
Such an integrated system will ensure the protection of 50 lakes and tanks found in the Padappai region of Lower Palar Basin Division of the Water Resources Department. PWD officials say they have been checking sewage inflow into lakes at the first instance of a complaint. They cite the example of Nanmangalam lake, where they not only closed a sewage channel but also removed encroachments.
