The abandoned quarries in Sikkarayapuram near Mangadu, which served as a lifeline during the drinking water scarcity in 2019 in the city, are filled up after recent heavy rain.
In a bid to divert a portion of Chembarambakkam reservoir’s surplus runoff water that otherwise gets drained into the Adyar, the Water Resources Department has prepared estimates to construct a channel to Sikkarayapuram quarries. The department is awaiting design approval for the ₹17-crore project.
The quarries, which are maintained as buffer storage by the Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB), at present have 280 million cubic feet (mcft) of water as against their capacity of 356 mcft. Officials of the board said the quarries had only 80 mcft of water before the start of the northeast monsoon. Good inflow through the earthen channel created to divert water from neighbouring areas like Malayambakkam boosted the storage.
The quality of water stored in the quarries was tested as part of a study on augmentation of surface water by Anna University. An ongoing project supported by the Union Department of Science and Technology, carried out by the Anna University’s Department of Geology and the Indian Institute of Technology Madras, suggested steps to store excess runoff of the Adyar basin in the quarries to mitigate the problem of flooding as well as boost storage.
“We have already put in place infrastructure to pump and convey water to Chembarambakkam water treatment plant. But the infrastructure remained unused for three years now as water from reservoirs are largely being drawn for supply now,” said an official.
The water board stored water in 25 quarries in Sikkarayapuram and seven in Erumaiyur. Officials said a few quarries in Pallavaram were being used as regular source for drinking water supply to Kundrathur and Anakaputhur.
The water board has identified more such quarries in seven or eight locations, including Thirusoolam, Paranur, Nallambakkam and Ottiyambakkam. Water could be stored and drawn from at least five quarries in each locality. They have a potential to store an additional 500 mcft of water, the officials added.
The department has chalked out plans to build a 2.10-km channel from Chembarambakkam surplus course at Kavanur to carry 400 cusecs of water to Sikkarayapuram quarries. “We built earthen channels to link floodwater from Nazarathpet, Poonamallee, Manapakkam and Thanthikal channel to the quarries. It helped alleviate floods in the neighbouring areas. These quarries could be used to ensure water security in other localities such as Mangadu and Kundrathur,” said an official.
Published - December 15, 2022 06:57 pm IST
