Safety of Mullaperiyar dam be reviewed by experts, Kerala tells SC

Tamil Nadu had submitted before the apex court that the dam was in a good condition and Kerala was 'creating obstructions' in carrying out the repair and maintenance work. Kerala's stand, however, is that a new dam should be constructed as the current one is 'not safe'.

New Delhi: The Kerala government has sought a fresh review of the safety of the 126-year-old Mullaperiyar dam by an independent panel of experts. The state has filed an affidavit in the Supreme court on the matter involving difference of opinion between Kerala and Tamil Nadu regarding the maintenance of water level and repair of the dam.

Tamil Nadu had submitted before the apex court that the dam was in a good condition and Kerala was 'creating obstructions' in carrying out the repair and maintenance work. Kerala's stand, however, is that a new dam should be constructed as the current one is 'not safe'. The state said that Central Water Commission (CWC) should consider including international experts as well while reviewing the safety of the dam.

The bench comprising Justice AM Khanwilkar, Justice Abhay S Oka and Justice CT Ravikumar had asked for Kerala's response on Tuesday over Tamil Nadu's affidavit. The matter was heard at length almost for the entire day in the court during which Kerala made the submissions. It said that comprehensive dam safety evaluation of dams is required to ensure that the structure is sound and performing safely in all respects and in the case of Mullaperiyar dam, it is highly essential as the catchment area and the structure was subjected to extreme rainfall during the recent years.

“It is therefore suggested as follows: (a) A fresh review of the safety of Mullaperiyar by independent panel of experts comprising qualified engineers and experts in the respective fields i.e. design, geology, hydrology, hydro-Mechanical dam safety, construction and supervision, instrumentation, seismicity should be conducted. CWC should consider including international experts also,” it said.

The state said that terms of reference of the study and details of the agencies for conducting the tests should be shared to the party states and approved by the supervisory committee. It said all tests and investigations should be conducted to check the hydrological, seismic and structural safety of the dam and the committee should ensure that study should be conducted with the participation of the officers of Kerala.

The affidavit said the test study reports and their findings should be shared with Kerala and finalised by the supervisory committee and it should be ensured that the study be completed within a time frame. The top court is seized of a batch of pleas raising issues pertaining to the dam, which was built in 1895 on the Periyar river in Idukki district of Kerala.

The Tamil Nadu government had last month told the apex court that it is “not justifiable” to have a fresh review on the safety of the dam before carrying out the strengthening measures ordered by the top court earlier. The state had said this in its response to a status report filed in January by the CWC and the supervisory committee which had said that a fresh review of the safety of the dam is now due and is required to be undertaken.

“In this water year 2021-22, water was stored in the dam at a level of +142 ft. from November 30, 2021, for about 18 days, and all the parameters of the dam were found to be within limits. Hence, there is no ground or necessity to have a fresh review on the safety of the dam for storing water up to +142 ft, now,” Tamil Nadu had said.

In a status report filed in the top court in January, the CWC and the supervisory committee had 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 had said the empowered committee, based upon the investigations, tests, and studies carried out by apex national organisations and specialist expert agencies, had concluded that Mullaperiyar dam was found to be safe in all respects — hydrologically, structurally, and seismically.

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 its response to the affidavit filed by Kerala, 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.