The Korattur check dam, with a regulator structure in Tiruvallur district across the unpolluted stretch of the Cooum, that was damaged during the 2015 floods, is set to be reconstructed.
Built in 1879, one of the oldest storage structures in Jamin Korattur is vital in regulating excess flood water to the Chembarambakkam lake which is a drinking water source to the city. The Water Resources Department (WRD) is set to float bids for the ₹32.45-crore project shortly and begin work in two months. Officials said a 50-metre portion of the checkdam was washed away in floods when the river carried 30,000 cusecs of water then. Another 50 to 60 metres of the structure was damaged during the floods.
At present, a temporary embankment has been created in the river near Tiruninravur to divert surplus water to Chembarambakkam lake. Several problems, including funding, had delayed the project.
The reconstructed structure would be 2.5-metre tall across the 140-metre-wide river.
Moreover, the river banks would be strengthened and flood prevention walls built. This would prevent inundation of the neighbouring villages, including Puduchatiram.
Minor repair would be taken up in head sluice that is used to divert water from the river to Chembarambakkam through the 7-km-long new Bangaru channel.
This is the fourth storage structure in the 72-km-long Cooum river.
Besides augmenting drinking water supply to Chennai, the structure that can store up to 10 million cubic feet of water would serve as a groundwater recharge source to surrounding seven or eight villages such as Gudapakkam and Tiruninravur, said an official.
“We expect the watertable to rise by 15 feet once the structure is built. Residents are demanding another storage structure in Sorancheri, 4.5 km downstream of the check dam, in Jamin Korattur,” the official added.