It will be built near Bandikavanur village in Tiruvallur district

Chennai may soon get another source of water to cope with the growing needs of the expanded city. The Water Resources Department has proposed to construct a check dam across the Kosasthalaiyar river near Bandikavanur village in Tiruvallur district, about 30 km from Chennai.

The check dam, a structure built across the river to break the flow of water and store it, will come up about 500 metre upstream of the Karanodai bridge on Chennai-Kolkata National Highway. At present, two check dams have been constructed across the river at Tamaraipakkam and Vallur. The facilities play a significant role in groundwater recharge as they can store water for nearly six months; the water would otherwise get drained into the sea.

The design of the proposed check dam will be similar to the one planned at Thirukandalam for which the State government recently announced a sum Rs.35 crore. About 250 million cubic feet of water will be stored at Thirukandalam and work will be completed by this year.

WRD officials said the Bandikavanur check dam would be constructed at a height of 6.30 metre across the nearly 300-metre-wide river.

The WRD has sent the proposal to the government for approval.

Flood banks too would be raised to create a riverine reservoir, a storage structure in the river. This would help store 100 million cubic feet (mcft) of water.

Every year, whenever the floodgates of Poondi reservoir are opened, a considerable volume of water gets drained into the sea through the Kosasthalaiyar river near the Ennore creek. Last year, about 200 mcft of water, which is approximately a week's requirement for the city, was lost when the reservoir filled up. The check dam planned at Bandikavanur would recharge the water table at a radius of 10 km. This would be a boon to many people whose main occupation is agriculture, officials said.

As many as 25 villages, including Erumaivettipalayam, Jagannathapuram, Alinjivakkam and Athur, would witness an improvement in water table. The well fields in Kannigaiper and Panchetti owned by Chennai Metrowater would also benefit from the check dam.

Metrowater could pump water from the facility and transmit water through a pipeline to supply Chennai. The check dam could be built without much hassle as acquisition of land is not required. The WRD has estimated that the project would cost Rs. 30.00 crore.