Supreme Court seeks Centre’s response on plea to decommission Mullaperiyar dam in Kerala

The Supreme Court on Monday sought the Centre’s response on a plea seeking decommissioning of the 130-year-old Mullaperiyar dam in Kerala’s Idukki district

The Supreme Court on Monday sought the Centre’s response on a plea seeking decommissioning of the 130-year-old Mullaperiyar dam in Kerala’s Idukki district.

The petition has highlighted that the dam does not have advanced seepage monitoring systems, which means that serious erosion of the foundation remains unmonitored. (ANI)

A bench of Chief Justice of India (CJI) Bhushan R Gavai and justice K Vinod Chandran issued notice while hearing a petition filed by Save Kerala Brigade, a non-profit organisation, which has sought exploring the possibility of constructing a new dam due to concerns over the safety of Mullaperiyar dam owing to climate change and heightened seismic activity.

The bench said, “The dam is one of the oldest, 130 years old. Some directions will have to be issued for strengthening it.”

While the dam, built in 1895, is situated on Periyar river in Kerala, near Tamil Nadu border, it has been maintained and operated by the latter based on a pre-independence lease between the British Government and the Maharaja of Travancore for a period of 999 years signed in 1886. “If another dam is constructed, Tamil Nadu fears its lease will go for a toss,” the court said as it sought the responses of Tamil Nadu, Kerala, National Disaster Management Authority (NDMA), and National Dam Safety Authority (NDSA).

Prior to decommissioning, the plea has requested the court for a holistic, expert safety evaluation of the dam, with national and international dam safety experts. Senior advocate V Giri and advocate Haris Beeran, arguing for the petitioners, said, “The lives of 10 million people living downstream of the dam are affected. This dam has to be decommissioned and a new dam built otherwise the results will be catastrophic.”

Giri said that several inspections by experts have revealed that the lime-surkhi mortar used in the construction of the dam has largely eroded, forming cavities and voids in the core of the dam. “The dam has been functionally deteriorated, with some upstream sections reportedly inclined forward,” he said.

While the two states are locked in a legal battle over dam safety in separate proceedings before the top court, the petitioner said that the fresh petition raises urgency in view of climate change which is affecting the weather patterns in the state and heightening dam safety issues with the current permissible water level at the dam fixed at 142 feet, on the condition that regular strengthening measures are undertaken.

“The petition is brought in the face of material changes in conditions such as global warming induced weather events, heightened seismicity, and weakening of dam materials, which were not addressed in earlier judicial processes,” it said.

The petition cited the fundamental right to life of citizens which is at stake as the petition points out that any breach of the dam would let havoc loose on six districts of Kerala, affecting more than 10 million people. “Flood waves would surpass 10-20 feet even at a distance of 100 km downstream and pose a threat to the Idukki Dam complex, reducing urban infrastructure, including sensitive ones like the Cochin Oil Refinery and Cochin Port to rubble,” the petition said.

The petition has highlighted that the dam does not have advanced seepage monitoring systems, which means that serious erosion of the foundation remains unmonitored. In 2024, senior engineers of the Kerala State Electricity Board (KSEB) claimed that the dam is in danger of collapsing, particularly under hydrological or seismic load.

The case pertaining to Mullaperiyar dam has been pending in court for over two decades. In 2006, the court permitted Tamil Nadu to raise the dam height from 136 feet to 142 feet. The Kerala Irrigation and Water Conservation (Amendment) Act, 2006, prohibited the raising of water level beyond 136 ft and placed Mullaperiyar in the schedule of “endangered” dams. This led to the state of Tamil Nadu filing a suit in the top court challenging the law.

A five-judge Constitution bench declared the law to be unconstitutional in 2014. Prior to this, the Centre made several attempts to broker a settlement between the two states with Kerala demanding construction of a new dam in the interest of safety of residents while Tamil Nadu insisted on strengthening the present dam.

A Supervisory Committee was also constituted for the management of dam safety in 2014 and in 2018. The top court in a PIL proceeding directed the NDMA and Centre to monitor the measures for ensuring high level of preparedness to face any disaster in relation to the Mullaperiyar dam.

In the suit filed by Tamil Nadu, the court is monitoring steps to strengthen the safety of the dam and passing ancillary directions for its upkeep.