With the water level in the Idukki dam, one of the highest arch dams in Asia, inching towards its full capacity of 2,403 feet, authorities have warned that the shutters could be opened soon. It is the shutters of Cheruthoni dam, which is part of the Idukki reservoir, that will be opened. There are three reasons that force the authorities to open the sluice gates of the Cheruthoni dam in Idukki before the water level reaches its full capacity.
Water inflow
Since the water level in the reservoir is rising fast, all the shutters of the Cheruthoni dam will have to be opened at the same time. This could lead to flooding and resultant damages. If the water is released in a controlled manner early enough, losses could be averted.
Encroachment
Since the Cheruthoni dam was last opened in 1992, largescale encroachment and illegal constructions have happened along the banks of the Periyar river. In several places, there were changes to the natural course of the river. If the sluice gates are opened and water released in a big way, widespread destruction is likely.
In 1981 and 1992, the sluice gates were opened after the water level crossed 2,401 feet. In 2013, though the water level crossed 2401.5 feet, the shutters were not opened. This time, it has been decided to open the shutters for a trial run when the water level reaches 2,397 feet.
Mullaperiyar dam
The current water level at the Mullaperiyar dam is 135.80 feet. The maximum permitted capacity of the dam is 142 feet. Once the dam is full, it is difficult to estimate how much water will flow into the Periyar through the spillway. Tamil Nadu has also refused to share with Kerala details in this regard. The water released will also flow into the Idukki reservoir.