Setting at rest the controversy over the safety of the 116-year-old Mullaperiyar dam, the Empowered Committee, headed by the former Chief Justice of India A.S. Anand, has said it is “structurally and hydrologically safe, and Tamil Nadu can raise the water level from 136 to 142 feet after carrying out certain repairs.”

In its report submitted to the Supreme Court on Wednesday, the committee is understood to have said: “The dam is seismically safe.” Last year's earth tremors in that region “did not have any impact on the Mullaperiyar dam and the Idukki reservoir and there was no danger to the safety of the two dams.”

The committee's conclusion is expected to bring relief to both Kerala and Tamil Nadu after apprehensions were raised on the Mullaperiyar dam's safety following mild tremors in that region. The committee gave its findings on the basis of the reports, studies and investigations conducted by various agencies constituted to go into the safety aspects. The committee was set up in February 2010 during the course of arguments on Tamil Nadu's suit questioning the law enacted by Kerala to restrict the water level in the dam to 136 ft.

On Kerala's demand for construction of a new dam, the Empowered Committee said that in view of the age of the existing reservoir, building a new one could be considered as an alternative proposal. If a new dam was constructed, the maximum water level (MWL) should be fixed at 155 ft and a fresh agreement signed between the two States on water sharing and maintenance.

Dissenting note

While Justice K.T. Thomas, retired Supreme Court judge representing Kerala on the committee, gave a dissenting note and said water level in the existing dam should not be raised above 136 feet, Justice A.R. Lakshmanan, retired Supreme Court judge representing Tamil Nadu, opposed the proposal for a new dam saying it was not necessary.

The committee framed five main issues: “Which strengthening measures as suggested by the CWC [Central Water Commission] have already been carried out by Tamil Nadu for the dam, each of the two: the main and baby dam components, to ensure its safety and stability based on the investigations so far carried out? Which remaining measures from amongst those suggested by the CWC are yet to be carried out by Tamil Nadu for the safety and stability of the dam and when will they be undertaken and completed? Should the reservoir level be raised from 136 ft.? If yes, what further measures for strengthening the existing dam do the two parties envisage to allow the raising of reservoir level to 142 ft. and beyond?”

Kerala proposed additional issues: “What are the needs of Tamil Nadu in the waters in the existing Mullaperiyar dam? Does Tamil Nadu suffer any injury, if the storage is not raised beyond 136 ft? Does the MWL go beyond 155 ft. submerging the lands which are not part of the Lease Deed of 1886? If so, to what extent? Will increase of storage beyond 136 ft. prejudicially affect the environment, ecology and biodiversity? Will the downstream Idukki dam collapse if the Mullaperiyar dam breaks? What will be the consequent loss of lives and property to both States?; What benefits would accrue to both States from the diversion of Periyar waters, under the alleged Lease Deed of 1886 and the supplemental agreements of 1970? Is Periyar an inter-State river?”

The Empowered Committee, which includes the former Secretary to the Ministry of Water Resources, C.D. Thatte, and the retired CWC Chief Engineer, D.K. Mehta, has answered all the issues in its 250-page report.

The case comes up for further hearing before a five-judge Constitution Bench on May 4.