In a major setback to the Kerala government which has been fighting a decade-old legal battle with its neighbouring state, a five-judge Constitution Bench headed by Chief Justice R M Lodha struck down a law promulgated by it declaring Mullaperiyar dam as endangered and fixing the water level at 136 feet.
The apex court pulled up the Kerala government for enacting a law which overruled its verdict of 2006 by which it had declared the dam safe and allowed the Tamil Nadu authorities to raise the water level. "It is declared that the Kerala Irrigation and Water Conservation (Amendment) Act, 2006 passed by the Kerala legislature is unconstitutional in its application to and effect on the Mullaperiyar dam.
"The State of Kerala is restrained by a decree of permanent injunction from applying and enforcing the impugned legislation or in any manner interfering with or obstructing the State of Tamil Nadu from increasing the water level to 142 feet," the bench said.
The bench, also comprising justices H L Dattu, C K Prasad, Madan B Lokur and M Y Eqbal, said the earlier judgement of this court given on February 27, 2006 operates as res judicata (a matter that has been adjudicated and not be pursued further) on the issue of the safety of the dam for raising water level to 142 feet and ultimately to 152 feet after completion of further strengthening measures. Mullaperiyar dam is a masonry dam and was constructed pursuant to the Periyar Lake Lease Agreement of 29.10.1886 across Periyar river.
The construction continued for about eight years and was completed in 1895. The dam is situated in Thekkady District in Kerala and is owned and operated by the government of Tamil Nadu. The length of the main dam is 1200 feet and top of the dam is 155 feet.