WRD moves to protect reservoir catchment areas from pollution after residents raise concerns

The Water Resources Department (WRD) has written to local bodies and the Tamil Nadu Pollution Control Board (TNPCB), seeking measures to prevent sewage pollution in the catchment areas of Chembarambakkam reservoir, one of the key drinking water sources of Chennai.

The move follows representations from residents to the department, alleging sewage inflows into the Cooum and other channels. Residents of fast-developing areas along the unpolluted stretch of the river said sewage from the neighbouring localities, which lack underground drainage infrastructure, was released into the river.

Residents of Manavala Nagar in Tiruvallur have long been demanding the protection of this stretch, which serves as a source for irrigation and groundwater recharge, from sewage discharge.

D. Anandhakrishnan, a resident of Manavala Nagar, said sewage entered the stretch between Putlur and Jamin Korattur checkdams through various inlets, including storm-water drains. With the river largely dried up, sewage discharge is more prominent, polluting groundwater and affecting the livelihood of nearly one lakh residents.

“This sewage contaminated water reaches the Chembarambakkam reservoir whenever water is diverted from the river through the Bangaru channel. The water channel is also polluted as households along the bank release sewage into it. Solid waste is also dumped on the river bank, as can be seen from Vellavedu Bridge built across the channel,” he said.

The nearly 8-km-long Bangaru channel, which branches out from the Cooum, also carries flood water from other tanks in the upstream areas. Residents have submitted a representation to the department and the Chief Minister’s cell. Though the department had assured them of storing floodwater near the checkdams during the upcoming monsoon, sewage pollution needed to be arrested, residents added.

In response to the residents’ plea, the WRD said Chembarambakkam reservoir’s catchment areas were recently inspected.

Officials said the department had written to the TNPCB authorities and block development officers to collect water samples and identify sources of pollution. Moreover, local bodies had been asked to ensure treated wastewater from sewage treatment plants was discharged into the waterways.

The WRD would coordinate with other government agencies to prevent sewage pollution, the officials said.