The Idukki dam will have to be opened with the water level just 6.72 feet shy of the full reservoir level and the good inflow continuing despite the slackening rain.
A senior Kerala State Electricity Board official said the dam would be opened this week or by next week. It was only a question of when.
The people living in the downstream areas have been alerted. Since the water will be released in a controlled fashion, a flood risk does not arise, officials say. But still, large river areas of the Periyar have been occupied by settlers. A control-room official told The Hindu that the shutters of the dam had been greased and other preparations made for releasing water. The dam has five shutters, and the central gate will be opened first followed by the two flanking it in a phased manner to keep the level at the full reservoir level of 2,403 ft. The water level on Sunday evening was 2,396.28 ft. District Police Chief M. Sheik Anvaruddin Sahib visited the Cheruthoni dam area on Sunday to review the steps taken and held talks with the officials of the control room.
It speaks of the windfall monsoon this time that the water level has gone so high to warrant preparations to op en the dam for the first time in August. On Sunday, the inflow through the Periyar and other tributaries was 509 million cubic feet per second. The catchment area recorded only 12.62 mm of rainfall on Sunday. But the inflow shows only a slight fall.
The water level in the Mullaperiyar dam upstream of the Idukki reservoir fell to 134.9 ft from 135.2 ft on Saturday. The maximum level maintained is 136 ft. Tamil Nadu has stepped up drawing of water and the rain has weakened in the catchment areas, helping reduce the level. This has reduced the threat of a sudden spurt in the inflow through the Periyar. However, even at this level of inflow, the Idukki dam has to be opened, an official said. An expert team led by K.K. Karuppankutty, Chief Engineering, Dam Security, which visited the Kulamavu dam of the Idukki reservoir, said the structure faced no threat from a breach of a neighbouring road.