CHENNAI: To prevent flooding in Chennai and surrounding areas and to improve the city’s water storage capacity, the water resources department (WRD) has planned to link 200 tanks in Adyar and Kovalam river basins.
According to WRD officials, the initiative is aimed at preventing flooding during monsoon in Chennai, particularly in places such as Tambaram, Mudichur, and Mannivakkam. A senior official said 90% of city’s rainwater flows into the sea due to lack of adequate storage structures, and linking of waterbodies will help address the issue.
Another official said 134 of 196 tanks in Adyar basin and 66 of 120 tanks in Kovalam basin have been identified for interlinking through ‘cut and cover’ method based on a survey of the two basins spread across Chennai, Kancheepuram, and Chengalpattu districts.
Under the ‘cut and cover’ method, instead of acquiring land for building open channels or to restore encroached canals, covered structure will be built below the ground level to carry excess water from one tank to another. Since the structure would be covered, the possibility of encroachment of water channels would be eliminated. This would also help reduce cost and speedy execution of the project, sources said.
Chennai’s water demand may touch 28 tmcft by ’30
The project, which is awaiting approval from state government, is expected to be rolled out with financial assistance from the Japan International Cooperation Agency, another official said. Chennai’s annual water requirement, for both industrial and domestic use, currently pegged at 22 tmcft, is expected to surge to 28 tmcft by 2030 due to population growth and industrial expansion. Augmenting the storage capacity of city’s water bodies is thus indispensible to meet future needs, the official said. The official also said that by interlinking the tanks, WRD wants to increase the storage capacity of Chennai’s drinking water reservoirs by four tmcft from 13.22 tmcft to 17.22 tmcft. While the historical records indicate the existence of 3,600 tanks in Chennai, Tiruvallur, Kancheepuram, and Chengalpattu districts, WRD currently maintains only fewer than 1,000 tanks in these districts. ENS