The Greater Chennai Corporation has begun work on a ₹80.25-crore stormwater drain in Korattur that is intended to reduce recurring monsoon flooding in Central Avenue, East Avenue, the Tamil Nadu Housing Board Colony and other nearby neighbourhoods.
The nearly 5-km Korattur stormwater drain is being executed in two phases. The first phase covers 2.44km and has an estimated cost of ₹40.36 crore. A Greater Chennai Corporation official said 1.8km of this stretch had been completed, while a stakeholders’ meeting had recently been held on the second phase.
The second phase will cover 2.5km at a cost of ₹39.89 crore. It is planned to connect the drainage network to the Cooum, allowing excess rainwater to be carried from the area towards the waterway. The drain begins near Kiran Palace, close to Central Avenue, and will run along GNT Road towards the Cooum.
According to the corporation, the project is intended to divert runoff from Korattur’s flood-prone areas and provide a relief channel for Otteri Nullah during periods of heavy rain. Residents in the TNHB neighbourhoods have reported flooding during every monsoon, making the capacity and connectivity of the new drain important to how quickly stormwater can be moved out of the local catchment.
The design and dimensions of the second phase were finalised after a survey conducted jointly with Chennai Metro Rail Limited and Chennai Metropolitan Water Supply and Sewerage Board, according to the official. The survey examined inflows from North Avenue and the surrounding catchment, along with the levels needed to connect the proposed drain to the Cooum.
The project’s design therefore involves more than constructing an isolated drain. Its effectiveness will depend on whether the new infrastructure can receive runoff from the identified catchment and maintain a functional connection to the Cooum. The survey was also used to determine the levels required for that connection, according to the corporation.
Residents have raised concerns about the effect of diverting additional water on Otteri Nullah and communities located along its course. Sandhya Vedullapalli, secretary of the Federation of Anna Nagar Residents Association, said flood mitigation should not worsen pollution in the waterway or affect the ecological health and well-being of nearby communities.
The second phase is the next major step in the project. Once completed, the full network is expected to create a longer drainage route from the Korattur catchment towards the Cooum while easing pressure on Otteri Nullah during heavy rain. The corporation has not provided a completion date in the information available.
