The Water Resources Department plans to continue water release from major city reservoirs till the end of the northeast monsoon.
Although there has not been significant rain in the past few days, the reservoirs continue to get inflow from catchment areas upstream. The officials said the storage of the five reservoirs that contribute a large share to drinking water supply is being maintained at a considerable level this month. The combined storage of the reservoirs, including Poondi, stood at 10,582 million cubic feet (mcft) against their capacity of 11,757 mcft.
“We have to build up storage of the reservoirs to nearly 90% of their capacity. It was decided to have the floodgates open till the end of monsoon as more rain spells may occur. A minimum 100 cusecs of water is being discharged from Red Hills and Chembarambakkam lakes. This would have residents downstream on alert as water release may go up during rain,” said an official.
This monsoon, the department was able to manage resources and build storage due to measured operation of the reservoirs during heavy inflow. Decision on water discharge was taken based on the forecast of the India Meteorological Department and the Central Water Commission.
“We released a maximum of 3,000 cusecs into Adyar river from Chembarambakkam reservoir. Flash floods were avoided. Kosasthalaiyar river carried more floodwater as it received heavy inflow consistently for many days,” the official said.
On Wednesday, about 1,940 cusecs was released from Poondi reservoir as it continued to get an inflow of over 2,600 cusecs. The department is maintaining water level at 34.53 feet against its full level of 35 feet. Once the rain recedes, storage in other reservoirs like Chembarambakkam would be stepped up.
Water is being diverted from Poondi reservoir to other waterbodies through the link canal. For the second time in a month, the department is diverting floodwater from the Kosasthalaiyar to flush the polluted stretch of the Cooum.
Water flowing in the link canal is routed to the Cooum near Aranvoyal in Tiruvallur district. The river is already getting 700 cusecs from tanks upstream and another 300 cusecs of water is added from the link canal. The continuous flow would help clean up the river.
