Fresh review of Mullaiperiyar Dam's safety now due, required to be undertaken: SC told

A fresh review of the safety of 126-year-old Mullaperiyar dam is now due and is required to be undertaken, the Central Water Commission (CWC) and the supervisory committee have told the Supreme Court.

The apex court is seized of pleas raising issues pertaining to the dam, which was built in 1895 on the Periyar river in Idukki district of Kerala.

In a status report filed in the top court, the CWC and the supervisory committee have said that aspects pertaining to the safety of dam were carried out during 2010 to 2012 by the empowered committee constituted under the directions of the apex court in 2010.

It said the empowered committee, based upon the investigations, tests and studies carried out by apex national organisations and specialist expert agencies, had arrived at a conclusion that Mullaperiyar dam was found to be safe in all respects -- hydrologically, structurally and seismically.

The status report said that in addition to the study conducted by the empowered committee, the supervisory committee had also visited the Mullaperiyar dam during the annual meetings held at the project site.

Till date, 14 meetings of supervisory committee have been held, the last one being on February 19, 2021, it said.

In the minutes of meeting of 9th, 10th, 11th, 12th, 13th and 14th meetings of supervisory committee, it has been recorded that overall condition of the dam and its appurtenant structure, based upon visual inspection, is found to be satisfactory, the status report said.

However, a fresh review of the safety of the Mullaperiyar Dam is now due and is required to be undertaken, it said.

The status report said that in a recent meeting of the supervisory committee held on December 8, 2021, Kerala had expressed displeasure on the erratic spillway shutter operation at the Mullaperiyar reservoir and the release downstream by the state of Tamil Nadu.

Tamil Nadu submitted that as the rainfall data was made available to them by Kerala on daily basis and not on an hourly basis as envisaged from installing telemetry system, they don't have sufficient time for making decisions in advance, it said.

The report said the supervisory committee, at its level, has requested Kerala to expedite the installation of requisite number of such telemetry stations so as to facilitate Tamil Nadu to provide timely inflow forecast which is used to release water from Mullaperiyar dam by opening gates.

However, Kerala has not yet acted on its commitment to install the telemetry stations, it said.

On January 11, the apex court had said that litigation pertaining to the dam is not adversarial as this is a public interest litigation in the sense that safety, security and health issues of the people staying around the dam are involved in the matter.

The top court had told the advocates appearing for the respective parties in the matter that they should assist it in identifying the core issues which needs to be addressed by the court.

It had posted the matter for hearing in the second week of February.

In the Mullaperiyar dam matter, the Kerala government had earlier told the apex court that "no amount of rejuvenation" can perpetuate the dam and there is a limit to the number of years one can keep dams in service through maintenance and strengthening measures.

It had said the only permanent solution for removing the "eternal threat owing to the safety concerns" of the dam and for protecting the safety of lakhs of people living the downstream of Mullaperiyar dam is to build a new dam in the downstream reaches of the existing dam.

In an affidavit filed before the apex court, the Kerala government had urged that the proposal to fix the upper rule level of Mullaperiyar dam at 142 feet on September 20 as formulated by Tamil Nadu may be avoided.

In its response to the affidavit filed by Kerala, the state of Tamil Nadu had said that repeated assertion of Kerala and petitioners from there in the pleas filed from time-to-time seek to decommission of the existing dam and construction of a new dam, which is wholly impermissible in the light of the apex court verdict on the safety of the dam.

"The dam has been found to be hydrologically, structurally, and seismically safe, Tamil Nadu had said.