With the Cooum, which has been in full flow in the unpolluted portion this monsoon, filling up most of the tanks in Tiruvallur district, the Water Resources Department has drawn up plans to build more check dams.
Abundant rain in November helped sustain flow in the Cooum. The river continues to get inflow from the Kosasthalaiyar and Kesavaram check dam upstream despite the rainfall receding in the last few days. Water from the Poondi reservoir is being diverted into the Cooum.
Officials said the check dam at Pudhumavilangai, which is located 12 km downstream of Kesavaram, has improved storage in four tanks at Agaram, Kadambathur, Kasavanallathur and Egattur. Besides storing about eight million cubic feet (mcft) of water in the check dam, floodwater is diverted to the tanks.
Proposals submitted
As there is scope for storing more water, the department has proposed to build check dams in three more locations at Perambakkam, Adigathur and Sorancheri and restore dilapidated structure in Aranvoyal. The project for 85-metre check dam at Perambakkam and the 100-metre structure at Sorancheri have been submitted to the State government. The cost for the two storage structures was estimated to be ₹12.6 crore.
Both the check dams are expected to boost water table and feed at least two tanks each. The proposal to construct check dam at Adigathur across the 200-metre wide river and store 15 mcft of water is under study. The British-era Korattur anicut, which was recently reconstructed, overflowed last month and discharged about 500 cusecs of water on Friday.
A minimum of 130 mcft of water will be stored in the existing five check dams across the unpolluted portion of the river.
The flow in the river till the Napier bridge had helped flush the stagnant sewage in the urban stretch. Steps were taken to tap the potential of the river in feeding more tanks, said the officials.
