Tamil Nadu released a high volume of water in different phases to the Periyar from Sunday night, while maintaining the water level in the Mullaperiyar dam just below the upper rule curve of 142 ft in the daytime.
At 6 p.m. on Sunday, nine spillway shutters of the dam were opened, releasing 7,341.06 cusecs of water to the Periyar. At 8.30 p.m., four shutters were closed, reducing the water release to 3,967.55 cusecs. At 10 p.m., the release was again reduced to 2,064.45 cusecs, while by 11 p.m., Tamil Nadu closed all spillway shutters except one.
However, at 4 a.m. on Monday, five spillway shutters were opened, releasing 3,967.55 cusecs of water, and, at 4.30 am, nine shutters were raised, releasing 5,668.16 cusecs of water.
Residents downstream of the dam said they keep vigil during night, even as some of them move to safer locations or board at houses of relatives. Some workers and farmers said they prefer to sleep during daytime and keep awake at night, which had been affecting their routine works.
Syam Sivan, a resident at Choorakkulam, said his family moves out of the house by evening every day and returns in the morning, attributing this precaution to the water level being maintained just below the maximum level in the daytime.
“Water suddenly appears to reach the maximum level after a rainfall. The shutters are suddenly opened. If the water level was kept at a safer level, this would have been avoided,” said Mr. Sivan, adding that there was no one to hear their grievances.
Vallakadavu resident P.N. Sebastian said that several workers were unable to go for work. “This is in addition to the old structure (dam) creating a threat to their life and security,” he said.
Orange alert
The district administration, meanwhile, issued an orange alert at the Idukki reservoir with the water level reaching 2,401 ft. The water level was on the rise with increased inflow in the Periyar from morning, touching the orange alert level by 5 p.m.
The upper rule curve is 2,403 ft., which is the full reserve level. The increased water flow from the Mullaperiyar and rainfall resulted in the rise in the level.
Meanwhile, one of the six generators at the Moolamattom power station was shifted for annual repair works. The lower intake of water for power generation also resulted in increased water level in the Idukki dam.
According to a dam safety official, there was no decision taken yet regarding opening of the Cheruthoni dam for regulating the water level.