Thiruvananthapuram/Thodupuzha: The water level in Mullaperiyar Dam showed a decreasing trend even as the reservoir downstream at Idukki started filling up.

The water level at Idukki was at 2,398.30 feet at 6 pm on Sunday, five feet short of its maximum capacity of 2,403 ft. The water level at Mullaperiyar, meanwhile, was 138.65 ft, and 2,752 cubic feet (approximately 77,928) of water was being discharged per second through the six sluice gates of the spillway.

Tamil Nadu, however, might close the gates of the Mullaperiyar Dam since the rule-curve norm would change on Monday, allowing it to store 139.5 feet of water till November 11.

(A rule curve or rule level specifies the storage of water which can be maintained in the dam every 10 days. It is meant to control floods. If the water level exceeds the limit set by the rule curve, the water from the dam will have to be released.)

The water level in the Idukki Dam has increased to 94.49% of its holding capacity. It has been anticipated that the dam's shutters need not be raised since the rule-curve norm has changed and the third generator at Moolamattom power station has been operational.

Kerala Minister for Water Resources Roshy Augustine said Idukki dam could hold water even if Mullaperiyar released 7,000 cubic feet (approximately 1.9 lakh litres) of water a second. The rule-curve was not brought down to 138 ft, the minister said, adding that it would be brought to the notice of the Supreme Court and the high-level committee.

Augustine was speaking to reporters after visiting Mullaperiyar Dam along with Agriculture Minister P Prasad. Chief Engineer Krishnan of Tamil Nadu's Public Works Department, too, visited the reservoir on Sunday.

Meanwhile, 11 dams of the irrigation department were on yellow alert, while orange alert had been sounded at five other dams. The Peechi dam is on red alert.

Red alert has been sounded at KSEB's dams at Ponmudi, Peringalkuthu, Kundala, Kallarkutty, Moozhiyaar, and Anathodu, while Idukki, Sholayar, Mattupetti and Anayirankal dams were on orange alert.

Nearly 130-year old Mullaperiyar Dam is over the Periyar River in Kerala's Idukki district. As per an agreement made during the British Raj, Tamil Nadu has been diverting water from the dam.

The Idukki Dam too is constructed across the Periyar River. The Idukki Dam, Cheruthoni Dam and Kulamavu Dam together form the Idukki reservoir.

The shutters of both Mullaperiyar Dam and Idukki Dam were raised recently as a precaution against floods following heavy rains.

Over 38 million units of power generated

Kerala consumed 73.19 million units of power on Sunday, of which 34.68 million units were bought from outside. The State, meanwhile, generated 38.50 million units, including 15.95 units at Moolamattom.