Mettur dam reaches full resorvoir level; flood warning issued in 11 Tamil Nadu districts

The outflow will increase gradually and it will be anywhere between 50,000 cusecs to 1 lakh cusecs, the advisory issued by the department said

With the catchment areas receiving heavy monsoon rains leading to heavy discharge of excess water from dams in Karnataka, the Stanley Reservoir in Mettur on Saturday achieved its Full Reservoir Level (FRL) of 120 feet.

With the outflow from Mettur set to be increased to 50,000 to 1 lakh cusecs as the dam reached its FRL, the Water Resources Department has issued a flood warning to people living on the banks of River Cauvery and in low-lying areas in 11 districts to move to safety.

The advisory has been given to Salem, Erode, Namakkal, Karur, Ariyalur, Tiruchirappalli, Thanjavur, Tiruvarur, Mayiladuthurai, Nagapattinam, and Cuddalore districts.

“The water level at Mettur dam at 8 am on Saturday was 119.29 feet. Since the inflow is high, the dam is likely to achieve its FRL by tonight. The outflow will be increased gradually, and it will be anywhere between 50,000 cusecs to 1 lakh cusecs,” the advisory issued by the department before the dam achieved its FRL said.

Read | Rains in Karnataka push water level at Mettur dam to 103 feet

It also said people living on the banks of Cauvery and in low-lying areas should move to safety, while asking the district administrations to take necessary precautionary steps. The water level at the 88-year-old Stanley Reservoir built by the British regime has been rapidly increasing since July 11 when Karnataka began releasing excess water from Kabini and Krishnaraja Sagar dams in Mysuru district.

At 9.55 am on Saturday, the water level stood at 120 feet and the storage was 93 tmcft. The inflow stood at 1.18 lakh cusecs, while the outflow was 25,000 cusecs. The water level has increased by over 20 feet in the past six days, while over 20 tmcft of water has been received in the said period alone.

The water level at Mettur dam increasing is good news to farmers in the Cauvery Delta who have cultivated the kuruvai (short-term crop) for the third straight year in a row. This year, the dam was opened in May for the first time since independence.

While paddy was cultivated in a record 4.9 lakh acre in 2021, the early release of water will help farmers increase the cultivation to 5.22 lakh acre this year, the government says, adding that water from Mettur dam is the lifeline of farmers in Thanjavur, Tiruvarur, Nagapattinam, Mayiladuthurai, and parts of Pudukkottai, Tiruchirapalli, and Cuddalore.

Besides cultivating lakhs of land, water from lower Cauvery is also used for drinking water purposes in 18 districts. The water also benefits around 30 industries.

The Cauvery Delta, which was used to a three-crop formula – samba, kuruvai and thaladi – had come down to just one crop a year. Till about a decade ago, cultivation would take place in three seasons – Kuruvai (short-term crop) from June to September, Samba (long-term crop) from August to January and Thaladi from January to May – keeping the farmer busy for the whole year.

While the first two seasons primarily cultivated paddy, farmers utilised the third season to cultivate pulses for centuries together with the progressive farming community.