Otteri Nullah drains floodwaters from the central parts of the city into the Buckingham Canal near Basin Bridge. The canal passes through north Chennai zones such as Ambattur, Anna Nagar and Thiru.Vi. Ka. Nagar. Residents along this key waterway have reported a slew of persistent civic issues. Even as the Greater Chennai Corporation and the Water Resources Department (WRD) have started cleaning the waterway ahead of the northeast monsoon, residents have demanded better coordination among agencies to resolve the civic issues, including pollution caused by industrial effluents, dumping of garbage, flooding of residential areas and public health issues. Many residents say the pollution results in corrosion of metals at home and damage to electronic gadgets.
‘It was clean once’
A 33-year-old resident of Agasthiyar Nagar at Villivakkam, who survived a health scare after a surgery last December, says many residents along Otteri Nullah have reported similar health issues. “My house is located right on the banks of Otteri Nullah, which flows one feet away from my compound wall. I used to bathe in the clean Otteri Nullah when I was 10 years old in 2000. Industries in the city have started letting effluents into the canal. I have noticed chemicals and coolants used by some of the major industrial units flowing in the canal. As I have worked as an engineer, I have been able to identify the chemicals that pollute Otteri Nullah. My health deteriorated after exposure to gases emanating from the canal. The health of several residents along the canal has deteriorated because of the pollution,” the resident said.
Following complaints from residents of areas like Medavakkam Tank Road near Kellys, the civic body has tried to ease water flow in the clogged stretch of the canal near the bridge. Residents complained that the section of Otteri Nullah was polluted near commercial areas like Purasawalkam. The colour of the canal water used to change from black to red to yellow at regular intervals. Now, the water is black, says a resident. “A new silver jewel purchased in the morning will turn dark by the evening because of the pollution from the effluents in Otteri Nullah,” says another.
No complaints, says TNPCB
R. Kannan, Member-Secretary, Tamil Nadu Pollution Control Board (TNPCB), points out that two to three years ago, there was the issue of drainage and sewage from Korattur and Ambattur flowing into Otteri Nullah. “We aren’t sure what the situation is, but no complaints have been made to the TNPCB,” he says.
Residents of Purasawalkam, Anna Nagar, Kilpauk, Ayanavaram and ICF are all affected by the pollution from industrial effluents and sewage. Mosquito breeding is also high in some areas because of garbage accumulation. As Otteri Nullah is a major rainwater carrier for many zones in the central parts of the city, the Corporation has planned to clear garbage along its course ahead of the monsoon. But the exercise has been held up by concrete slabs placed in the canal in some areas.
S. Sheik Abdul Rahaman, Regional Deputy Commissioner (Central), Chennai Corporation, says the civic body has asked WRD officials to clear the canal ahead of the monsoon. An official adds that the WRD has so far completed nearly 30% of the work to ensure that the waterways carry floodwaters without hassle during the rains.
Challenges from narrow stretches
According to WRD officials, the department has planned to complete the work by mid-September. The 10.8-km Otteri Nullah poses a challenge to the department with its narrow stretches. The waterway courses through residential localities developed by the Tamil Nadu Housing Board in areas such as Anna Nagar before it drains into the Buckingham Canal. Most of the residents who are affected by the civic issues are those who purchased small plots (measuring 900 square feet), meant for the weaker sections, from the TNHB a few decades ago. The road width is only 30 feet on many approved layouts developed by the TNHB, residents say. In the absence of proper access, desilting the waterway is an arduous task. On some of the stretches, cranes are being used to remove floating waste and vegetation to ensure better water flow during the rains.
The WRD project has been split into seven components for simultaneous execution ahead of the monsoon. Various bridges across Otteri Nullah, such as O Block bridge, and Aspiran Garden bridge, and the point of confluence with the Buckingham Canal at Basin Bridge are covered in the ₹1.85-crore project to desilt the waterway. The silt removed would be either conveyed to the Kodungaiyur dump or deposited on the banks of the Buckingham Canal, officials say.
Sludge from infrastructure projects such Metro Rail had clogged the waterway near Padi a few months ago. The WRD also plans to remove sludge from some stretches this year as residents along the waterway bear the brunt when the canal carries the maximum quantum of water. This would further improve the canal’s flood-carrying capacity, officials say.
Metrowater cleans sewer network
Following complaints from residents about sewage discharge into Otteri Nullah at frequent intervals, Metrowater is desilting its sewer network and maintenance holes and improving the operation of sewage pumping stations in the core areas. To keep pace with the growing demand, Metrowater has hired a consultant to study the decades-old sewerage in the city and recommend improvements. The exercise is expected to be completed by November. The core areas face the recurring issues of choked sewer lines, water contamination and sewage overflows. These problems turn grave during the northeast monsoon. The water agency has hired a consultant to assess the condition of its sewerage infrastructure. The consultant will have to identify the chronically affected areas and recommend improvements, an official says.
Anna Nagar Ward 104 councillor T.V. Shemmozhi has written to the Commissioner, highlighting the serious issues along Otteri Nullah. “Factory sewage and untreated effluents from areas such as Patravakkam are causing civic issues in areas like Anna Nagar. Otteri Nullah, which is supposed to carry rainwater, is flooded with sewage and clogged with garbage. The canal passes through various wards and the chemicals in the effluents are causing damage to electronic gadgets. The issues of health and silver tarnishing have been discussed with officials of various departments. These issues are often neglected and officials are saying it is a matter for the PWD to handle. But Metrowater also has to take responsibility,” he says.
J. Balasundaram, general secretary, Mullai Nagar Cultural and Religious Association, says the residents along Otteri Nullah have requested the government to close the canal with concrete slabs and build a wall along the stretch to prevent industrial effluents from affecting their health.
M. Sivaguru Prabakaran, Regional Deputy Commissioner (North), Chennai Corporation, says Otteri Nullah plays a key role in mitigating floods in parts of north Chennai also. “The Corporation has started construction of a sump near Stephenson Road Bridge across Otteri Nullah to pump floodwaters from the north Chennai areas. Shutters will prevent the water from flowing back if the level increases in Otteri Nullah. The work will be completed shortly,” he adds.
(With inputs from Geetha Srimathi)