It noted that a committee had already been formed, as ordered by a Constitution Bench in May 2014, to cover the dam’s safety and lifespan. The order came on a petition to direct the government to appoint an international agency to study the longevity of the dam, a perennial source of water and controversy between Tamil Nadu and Kerala, built in 1895.

The petition was filed by advocate Russell Joy, representing three million people living downstream, in the direct line of a catastrophe that may arise from a dam burst. It said the dam was constructed “as a composite gravity structure” across the Periyar, with “crude lime surki mortar, at a time when dam engineering was in its infancy...” It was built for 50 years and had already survived 122 years.

“People live in fear. Do we require the Bhopal gas disaster or an Ockhi [cyclone] to understand what a disaster is? Kindly have ready an emergency plan. Please don’t wait for the structure to be broken to act. We have a right to life,” said advocate Manoj George, for the petitioner.