Red Hills reservoir’s surplus course undergoes a major revamp after several years

After nearly two decades, the surplus course of Red Hills reservoir is undergoing a major revamp. Work has been started to improve the channel’s vulnerable portions and protect downstream areas from inundation.

Every year, when the shutters of the Red Hills reservoir are opened to release surplus water into the channel, areas located downstream face the threat of remaining marooned under sheets of water. The ₹10 crore project aims to provide relief from peak flow spillover for residents in low-level areas.

The Water Resources Department has started work to construct flood protection wall for a length of 300 metre along the surplus course near Naravarikuppam. Officials of the WRD said the wall would not shrink the space of the course and only replace the bund in vulnerable portions. This would prevent floodwater from inundating areas downstream of the waterbody and safeguard the channel from encroachments.

The surplus course of Red Hills reservoir travels for 15 km through various areas before it joins Ennore creek. Officials said there is a defined course for the channel for only 8.5 km. The earthen bund of the channel would also be improved for 2 km. Silt removed from the channel bed would be used for the work.

Many of the old inlets that carry water from stormwater drains into the channel would also be repaired between Naravarikuppam and Kosapur. “We are planning to construct an inlet to allow water that stagnates near the main bund to flow into the surplus course,” said an official.

S. Sameer, founder, Social Work Team Trust, a non-governmental organisation in Red Hills, said improvement of the surplus course was a long-pending demand of the residents. Several of the patta lands get submerged whenever the surplus course flowed to its full capacity. The work is much needed to alleviate flooding in the surrounding areas particularly Vadakarai and Naravarikuppam during northeast monsoon.

Recalling that the butterfly park being developed near the reservoir also bore brunt of the December 2023 floods, Mr.Sameer said the work would be resumed after the ongoing works.

Officials of the WRD said the surplus course would have a carrying capacity of 12,500 cubic feet per second after the project is over by October.

There are plans to construct a flood protection wall near Kosapur where a portion of the bund was washed away last year. The ₹12 crore project would be executed in the second phase.