After a lull, the water level in the Mullaperiyar and Idukki dams is rising following heavy rainfall from Thursday night.
The district administration on Friday issued an orange alert in the wake of the water level in the Idukki reservoir crossing 2,398.03 ft.
The water level in the Mullaperiyar dam, which has been almost steady for the past few days, rose to 139.10 ft with increased inflow and the tunnel discharge being reduced to 467 cusecs. The inflow was 3,967 cusecs at 3 p.m.
The Vaigai dam storing water from the Mullaperiyar dam was opened two days back following heavy rainfall in Tamil Nadu.
The water level in the Idukki reservoir on Thursday declined to the blue alert level from orange alert, as per the new rule curve fixed by the Central Water Commission. However, following good inflow, water level increased to 2,398.2 ft on Friday morning.
District Collector Sheeba George said, if needed, the water level in the reservoir would be limited by releasing water. She said if rain continued at the present level, the Cheruthoni dam shutters may be opened on Saturday after 4 p.m. or on Sunday morning to release up to 100 cusecs.
As per the new rule curve, the red alert level is 2,399.03 ft and the upper rule curve 2,400.03 ft. (The full reservoir level is 2,403 ft).
A dam safety official said the new rule curve in the Idukki reservoir was applicable from Thursday onwards. He said release of a small quantum of water would not have much impact downstream, as arrangements were already in place as the dam shutters had been raised last month. In case of a decline in rainfall, the chances of opening of the shutters were remote.
However, opening of the shutters of the Cheruthoni dam would be considered if water was released from the Mullaperiyar dam and there was heavy inflow into the Idukki reservoir.
He said power generation at the Moolamattom power plant was at the maximum and the discharge to the Kulamavu dam was also high which reduced the chances of opening the Cheruthoni shutters.
