The Cooum will get one more check dam on its unpolluted stretch at Adigathur, located about 60 km from Chennai, by early August. The storage structure will help recharge groundwater in areas falling under a semi-critical zone, where groundwater extraction is above 70%.
This will be the third check dam on the river from Kesavaram anicut and 7 km downstream of Pudhumavilangai check dam. Officials of the Public Works Department said nearly 85% of the storage structure being built across the 200-m wide river has been completed so far.
Once the ₹17.7-crore project is finished, several villages, including Egattur, Thandalam, Kadambathur, Selai and Melnallathur, will benefit from a better groundwater source for drinking and agriculture needs. The region is still known for the cultivation of groundnuts, paddy and guava. The water table, which is now available at a depth of 35 feet, is expected to improve to 15 feet as the check dam will store excess flood water, officials said.
Only work to form the bund for a distance of 4 km with ‘savudu’ earth sourced from the Adigathur tank is pending due to want of approval. The Cooum has a capacity to carry a flow of 25,000 cusecs (cubic feet per second) in the stretch. The check dam will be able to store about 50 million cubic feet and retain water in the river for a stretch of 2 km upstream of the structure. “Such check dams will store water even during the summer months. It will enrich the groundwater table and help irrigate about 540 acre of land in neighbouring villages,” an official said.
The river already has check dams in other places such as Korattur anicut and Putlur. The department plans to construct storage structures for every 5 km along the river to conserve the maximum amount of runoff, which otherwise flows into the sea.
