The Water Resources Department (WRD) plans to start work on the construction of a channel from the Somangalam tributary to the Adyar river, and to take up other improvement work at the river, by early March. The project is set to reduce flooding in the southern suburbs.
Every year, areas such as Royappa Nagar, Mahalakshmi Nagar, Varadharajapuram and West Tambaram remain inundated for several weeks whenever there is peak flow in the Adyar. As many of these surrounding areas are at a lower altitudes than the river, there is difficulty in draining floodwater when the water flow in the Adyar reaches its maximum capacity.
Officials said the bypass channel was one of the remedies proposed to divert a portion of floodwater flowing into the river as part of the nearly ₹70-crore project to mitigate floods in the city’s southern suburbs.
A cut and cover channel would be built at the Somangalam tributary-Adyar river confluence point upstream of these flood-prone areas. About 850 cusecs of excess water would be conveyed through the channel for 2 km and it would join the river about 750 metres downstream of the Outer Ring Road bridge. This will help arrest spillover of floodwater into neighbouring areas, and ensure smooth flow of floodwater where there is more width in the river.
Work is expected to be completed by the next northeast monsoon as there is no land acquisition required for the project, the officials said.
Moreover, dense rocks in the riverbed near Tiruneermalai would be cut as they often prove to be a hindrance for smooth flow. The department would increase the depth of the river by a minimum of two feet in flood-prone areas to enable improved flood-carrying capacity.
Flood protection walls would be built for a height of 4 metres along vulnerable areas, including in Adanur and Tiruneermalai, to prevent breaches in the waterway, the officials said.
