Mullapperiyar dam in Kerala remains a powder keg. It would surprise many that a 112-year-old dam, built with lime surkhi mortar, is still in service. In the United States, for example, decommissioning would be considered when a concrete dam is 50 to 60 years old.
t may also sound inexplicable that Tamil Nadu, which is the beneficiary of the dam, had been able to win a case in the Supreme Court of India against keeping he water level low. The water level had been lowered from full reservoir level of 152 feet from the base of the dam to 136 feet when the dam showed signs of trouble back in 1979. Though repair works had been carried out, the safety of the structure remained in doubt and led to the dispute between Kerala and Tamil Nadu before the Court.
Again, to the surprise of many, the Court observed that even if the dam failed, the waters would be contained in the Idukki reservoir down stream. Apparently, the Court had not been told about the thousands of people living between the Mullapperiyar and Idukki dams and catastrophic character of a dam failure. Kerala had always been fighting its cases against Tamil Nadu disastrously.
The only solace is that the authorities have now set up control rooms to watch the situation as water level has reached 136 feet. (But the control rooms and disaster management set-ups will be little help in the case of a dam failure). Tamil Nadu is also making moves to increase the water level by lowering the spillway shutters, despite the favourable court order. It also has realised that it would not be safe to test the dam. Meanwhile, the risk to the downstream population keeps on increasing.
Mullaperiyar, Idukki dams facing risk