CHENNAI: Following incessant rains in Chennai and its neighbourhood, water was released yet again from the Chembarambakkam and Red Hills reservoirs on Tuesday evening.
"More than 30 mm rainfall has been recorded in the catchment areas of Chembarambakkam and Red Hills. Both the reservoirs have been receiving 500 cusecs of water. The same amount of water has been released to avoid flooding. If the rains continue, more water may be released," said an official from the Public Works Department.
However, the release of water increased by the end of Tuesday. Though officials did not confirm, sources said more than 2,000 cusecs of water was being released.
While the water from Chembarambakkam was released into the Adyar river, water from Red Hills was released into the Kosasthalaiyar river.
People residing in low-lying areas near Chembarambakkam and Adyar lake including Sirukalathur, Kavanur, Kundrathur, Thirumudivakkam, Vazhuthiyampedu, Thiruneermalai and Adyar among others were issued a flood alert.
The total storage level in all the six reservoirs of Chennai -- including Veeranam in Cuddalore district -- touched an all-time high of 12 TMC as against the total capacity of 13 TMC.
The Red Hills reservoir which is spread over 20.89 square km has a total storage capacity of 3,300 million cubic feet. On Tuesday, the water level stood at 3,206 mcft (97 percent full). Flood warning has been issued in low-lying areas including Vadakarai, Puzhal, Vadaperumbakkam, Manjampakkam, Manali and Sadayankuppam.
Similarly, the water level at Chembarambakkam on Tuesday stood at 3364 mcft as against the total capacity of 3645 mcft (92 percent full), while the water level at Poondi was 3,135 mcft (97 percent full), Cholavaram was 81 percent full and Thervoy Kandigai was 80 percent full.
For the first time since 2015, water was released from Chembarambakkam reservoir in the last week of November after it received copious amounts of inflow due to cyclone Nivar. Similarly, the sluice gates of Red Hills reservoir were opened in the first week of December.
Ever since, water was being released from the reservoirs to maintain the level. However, officials assured that most of the water is being collected in check dams and not going waste.
Recently, the Tamil Nadu government has proposed to construct a check dam and a cut-and-cover channel to store surplus water from Chembarambakkam lake in a nearby stone quarry. At present, excess water from the lake enters the quarry pit in Sikkarayapuram through Manapakkam Channel at a maximum rate of 50 cusecs.
But in case of heavy rains, more water from Chembarambakkam could be discharged into the quarry pit as it has a storage capacity of 500 mcft. Currently, only one-fifth of this is utilised.
Also, funds have been sanctioned to widen the Adyar river (up to 120 metres) on the downstream side of the Chembarambakkam confluence point so that water gets discharged at a better rate.