Deluge over but check-dams in Chennai yet to get their fill
By Ashmita Gupta | Express News Service | Published: 18th December 2016 01:48 AM |
CHENNAI: Even as cyclone Vardah brought much pain and rain, it has hardly helped in raising the water level in the check-dams around Chennai, an analysis by the Anna University has found.
The researchers from the Department of Geology checked the water level in check-dams in Periyapalayam, which is 40 km north of Chennai, before and after the cyclone. But there seems to be almost nil improvement in water level. Earlier before the cyclone, when the research team monitored the water level in the check dams in the area in comparison to last year, it was found almost negligible. According to Professor L Elango, head of Geology Department and the initiator of the research, while it was expected that the cyclone would fill the check-dams, it was found the water level was less than 10 per cent of the last year’s water storage.
For monitoring the water level, Paleshwaram check-dam, which is the biggest check-dam, was mainly taken for their study, the professor said. The study was also conducted in eight other check-dams.
“Regularly water level was monitored in Paleshwaram check dam while in other eight dams the research outcome of Paleshwaram check dam was extrapolated to the remaining check-dams by mathematical modelling.
“The water level in these dams was monitored once in a month,” he said. Besides Paleshwaram check-dam, the other check dams include Surutapalli, Uttukotai, Panapakkam, Kalpattu, Sengothkalam, AN Kuppam, Lakshmipuram Ancient and A Reddipalayam.
A total of water storage in each of these check dams last year amounted to 4.42 million meter cube. “This year before the cyclone it was 10 per cent of the last year’s water storage. After the cyclone it is less than 10 per cent,”said the professor disappointed.
After Vardah, in Paleshwaram check dam, less than one foot water was found, he said. “Water level calculation can be made only when there is reasonable water in the check-dams. With meagre water in the dam, we can’t calculate the water level. Approximately the height of the water level may be 1 mm or 2mm in the dam,” he said.
S Parimala Renganayaki, an assistant professor at VIT Vellore involved in the research, said that at the bottom of the check-dam there is very less water left. “Whatever meagre amount of water is there in the dam, in two or three days 50 per cent of water will get evaporated and 50 per cent will be recharged,” she said.
Even before 2015, since 2010 due to sufficient rain, the storage in the check-dams was at a reasonable level, she added. She speculated that by April end of 2017 there won’t be any water left in the dams and it will not recharge the groundwater table either.