The Supreme Court on Monday allowed the water level of the Mullai-Periyar Dam to be raised from the present 136 feet to 142 feet.
A three-judge bench comprising Chief Justice Y K Sabharwal, Justice C K Thakkar and Justice P K Balasubramanyam, allowed petitions filed by the Tamil Nadu government and Janata Party president Dr Subramanian Swamy.
Regarding its plea to further raise the water level to 152 feet, the court asked the Tamil Nadu government to appoint an expert committee to determine if the repair work already undertaken was sufficient for the purpose.
At the instance of the apex court, the Centre had appointed an expert committee that recommended raising the water level initially to 142 feet.
The committee, after taking into consideration the stability of the dam, stress and strength analysis and every other aspect had refuted the apprehensions of the Kerala government about the safety of the dam.
The Centre accepted the report and informed the court accordingly.
The Tamil Nadu government contended that the committee had suggested strengthening measures but engineers from Tamil Nadu were prevented from carrying out the necessary repairs.
It said that since 2001, Tamil Nadu was deprived of the benefits of raising the water level and estimated the loss of power generation at about 171 million units.
Kerala's stand had also prevented Tamil Nadu from irrigating thousands of acres of paddy growing land, it was further alleged.
However, Kerala had maintained that the expert committee's report was unreliable, not scientific and the state's views were not properly considered.