After Chembarambakkam and Poondi, shutters of Red Hills reservoir, another major source of drinking water supply to the city, were opened on Friday evening.
Initially, 500 cusecs (cubic feet per second) was released from the reservoir as the inflow was good. The Water Resources Department (WRD) decided to release water from the reservoir as the water level touched 19.89 ft, just 1 foot short of the maximum level. The storage was 2.99 tmcft on Friday evening as against its capacity of 3.3 tmcft.
Following this, the Tiruvallur Collectorate issued a flood alert for the downstream areas.
An official said, “We had to release water as the group of tanks upstream had surpluses and more inflow was coming to the waterbody.” Among the group of tanks feeding Red Hills reservoir are Morai, Pammadhukulam, Vellanoor, Iyyaneri and Pothur.
Water released into the 13.5 km-long surplus course travels through areas such as Grandline, Naravarikuppam, Vadaperumbakkam, Manjambakkam and Kosapur before joining Kosasthalaiyar river and Buckingham canal near Sadayankuppam.
“The course has a capacity to carry 7,500 cusecs safely. We raised the water release to 650 cusecs around 6 p.m. However, it will be reduced by Saturday morning,” the official added.
Buffer source
Cholavaram lake, which largely remains dry and is used as a buffer source, has a storage of 650 mcft against its capacity of 1,081 mcft. As inflow into the Chembarambakkam and Poondi reservoirs had increased on Friday, discharge was adjusted to maintain the level.
The level at Chembarambakkam continued to be maintained at 22.45 feet, 1.5 feet short of the full reservoir level. About 3,000 cusecs of water was released into Adyar river around 6 p.m.
Similarly, inflow of 5,341 cusecs into Poondi reservoir was discharged into the Kosasthalaiyar. The surplus is yet to reach the tail end of the river near Ennore creek.
