WRD to dry up 28 tanks to hold excess water during monsoon

CHENNAI: With the northeast monsoon nearing, the Water Resources Department (WRD) has planned to completely dry up 28 tanks, excluding major reservoirs, within the Greater Chennai Corporation limits to significantly reduce the chances of flooding in the city and surrounding areas. These 28 tanks, with a water spread area of over 11,086 hectares, can hold about 6.33 million cubic metres (or 0.22 tmc) of water. Explaining what he termed as the pre-empty approach, M Mahesh Nagarajan, superintending engineer of WRD, told TNIE that the idea was to empty or reduce the water level in lakes and other water bodies before heavy rains to create extra space to hold incoming floodwater. He added that after the peak flood situation passes, the stored water will be released in a controlled manner. This method will not only reduce flooding in low-lying areas but also ensure water is stored and used effectively later. Apart from this, the WRD has constructed new regulators at Porur, Cholavaram, Puzhal, and Korattur lakes this year to use them instead of surplus weirs for better flood management. A few more proposals have been given to the state government to construct more regulators in and around Chennai. Earlier, surplus weirs were used, which could not be adjusted like regulators. Now, with regulators having gates, we can open or close them as required to manage flow and pressure. This will allow us to release water slowly within the carrying capacity of canals, the official added. Focus has also been given to the south and north Buckingham Canal, Cooum, and Adyar rivers to ensure free flow of water. Efforts are being taken to clear water hyacinth, plastic waste, and other blockages to improve storage capacity. Though most of the flood mitigation works will be completed by the end of September, we will continue certain activities such as strengthening of bunds till December, the official said.