For the Mullaperiyar, IIT-Roorkee estimated in its report to Premachandran that it would fail if an earthquake of 6.5 magnitude occurs in a radius of 16 km when the water level in the dam is at 41 meters. According to the UN study, such an event would endanger the lives of 3.5 million people in Kerala.

What will happen to Kerala if Mullaperiyar dam breaks?

If the dam-break were to occur at the maximum water level of 136 ft at Mullaperiyar, it will cause the water level at the much larger Idukki reservoir situated 36 km away to rise by 20.85 metres.

Is Mullaperiyar dam safe?

The Mullaperiyar dam is protected from earthquakes and is hydrologically safe, the Tamil Nadu government assured the Supreme Court. Countering Kerala's allegations of non-cooperation and lack of concern for the safety of the 126-year-old dam, Tamil Nadu accused Kerala of an “obstructionist attitude”.