CHENNAI: Though the state received 3.5 times more Cauvery water than the quantity Karnataka is legally required to give last water year, around 60% of it ended up in the sea as the state does not have the capacity to store it. As per the data accessed by TNIE from the water resources department (WRD), Tamil Nadu received 667.67 TMC (Thousand Million Cubic Feet) of water from Karnataka from June 2022 to May 2023, against the legal mandate of 177 TMC.
According to a senior WRD official, most of TN’s waterbodies, including the Mettur dam, were nearly full due to the excess rain the state received, and most of the surplus water was released into the sea.
A conservative estimate pegs the water let into the sea at a whopping 400 TMC.
“It’s impossible to store all the water during the rainy season. And, the surplus water should be let into the sea for ecological reasons. However, the state government has the responsibility to enhance the storage capacity by building more check dams and maintaining the existing tanks,” said Professor S Janagaraj, a renowned water management expert.
He said there are 990 tanks in the Cauvery basin, and if they are all designed and maintained, surplus water could be stored during such years. G Ajeethan, state general secretary of the Tamil Nadu Banana Growers’ Federation, said river-linking schemes, like the Cauvery-Agniyar-South Vellar-Manimuthar-Vaigai-Gundar link canal scheme, can also help preserve water.
A senior WRD official told TNIE, “The detailed project report for the interlinking of rivers within the state has been prepared, and the state has obtained approval from the union government.”
It is learnt that the Revenue Department is currently in the process of acquiring land in a few districts including Pudukkottai, Tiruchy and Karur and an Environmental Impact Assessment Study has been conducted in the project area.
Officials also said the state government is committed to constructing check dams, and work in this regard is already on in a few districts. “One positive aspect is that there is sufficient water storage in the Mettur dam, and it will be possible to open the dam for Kuruvai cultivation on the traditional water release day of June 12,” added Ajeethan.