Express News Service
CHENNAI: Despite the funding sanction, the authorities did not take over the drainage of Lake Chembarambakkam over the years, and experts say this was the main reason why water had to be released from the reservoir on Wednesday.
Officials from the Public Works Department confirm that at least 15 percent of the lake is full of silt and that deepening works have not started either. After heavy rains on Wednesday night, the release of water from the reservoir increased to 5,000 cusecs. The water level was 21.5 feet, compared to the lake’s total capacity of 24 feet.
The proposal
For the first time since its construction more than a century ago, a project was started in 2019 to clean up Chembarambakkam Lake and three other reservoirs at a cost of around Rs 36 crore. The project was also expected to generate additional income from the sale of collected silt.
The Chembarambakkam slime was only expected to generate 191 million rupees. The plan was to completely descale the lake, which has a storage capacity of 3,645 mcft, over an eight-year period. Up to 151.80 lakh cubic meters of silt had to be removed.
What really happened
Despite the work orders being sanctioned, the project was delayed for more than five months in 2019, due to the onset of the monsoon. According to official records filed last year, silt made up 3 percent of the lake.
When contacted by a senior PWD official, he confirmed to Express on Wednesday that 15 percent of the lake, which may hold about 550 mcft (6,365 cusecs) of water, was filled with silt. In addition, experts say that deepening the lake would have increased its capacity by more than three times compared to the results of dehydration.
‘Not a drop would have been wasted if …’
According to water management expert S Janakarajan, more than a third of the Chembarambakkam reservoir is filled with silt. “First of all, the government never conducted a silt study to find the quantity and quality of the silt. Therefore, no one knows the exact amount of silt. The government personnel just brought a JCB and picked up the silt at random. This only creates holes inside the reservoir, which is even more dangerous, “he said.
“Not a drop of water would have been wasted if the deepening and desalination works had been completed. If not for the desalination, officials should have deepened the lake to return it to its original capacity,” he added.
S Thirunavukarasu, a retired PWD official, said: “One year is enough to clean a reservoir. We could have saved more water that way. Last year, the reservoir was completely dry. If the depth had been increased, it would also have added as carryover storage. “
“Although the cyclone is an unforeseen calamity, Chennai always forgets to clean its reservoirs and seeks water during the summer. If it rains heavily as expected, more than 20,000 cusecs of water will have to be released from Chembarambakkam. At least a quarter of it will have to be released. that could have been saved, “he added.
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