The Supreme Court in the order dated 27th February, 2006 in Writ Petition 386 of 2001- Mullaperiyar Environmental Protection Forum vs. Union of India and Others, only considered whether the water level of the dam could be raised beyond the present level of 136 feet.
The Supreme Court permitted the water level of the dam to be raised to 142 feet relying on the opinion of the Technical Committee of the Central Water Commission.
The Court did not pass judgment on
-the validity of the agreements of 1886 and 1970
-recourse to resolution of disputes under the Inter-State Water Disputes Act 1956
though these issues were also raised by the petitioner.
The Supreme Court allowed raising of the water level from 136 feet to 142 feet based on the expert opinion of the Central Water Commission's Technical Committee that strengthening measures were adopted by Tamil Nadu and that the dam was safe. The strengthening measures mentioned are cable anchoring and RCC capping and RCC backing of the rear face of the dam. It was mentioned that several strengthening measures were still pending.
The Supreme Court did not validate the technical opinion from independent sources to conclude that the dam was safe. The Court did not consider threat factors such as age of the dam and deterioration of the core, the high elevation of the dam and the threats arising from floods and earthquakes in a detailed manner. The Court did not analyze the opinion of the Central Water Commission experts to come to its own independent conclusion.
The Court did not consider why Tamil Nadu wanted the water level to be raised to 142 feet, what the genuine water needs of Tamil Nadu are, whether those requirements were covered by a binding contract and whether those needs could be met by lowering the water level and increasing the intake from the dam's dead storage. It would be seen that there was dead storage of around 7 tmc of water below the water level of 104 feet that is the level of the tunnel diverting the waters.
The Supreme Court judgment was not backed up by sufficient technical data or analysis to come to a justifiable conclusion that the aging dam was safe to hold nearly 13 tmc of water at the 142 feet water level at a 2800 feet elevation from msl. The Supreme Court also did not specify for how many years more this water level or higher water levels could be sustained by a dam that was 110 years old (in 2006).
The Supreme Court also erred in not fully considering the likely impact of a potential dam failure and whether contingency plans were in place.
The safety of the dam has to be revisited considering various threat factors and based on risk assessment and disaster impact analysis. It is hoped that the Empowered Committee will critically examine these factors to help the five member Constitution Bench of the Supreme Court to pronounce a judgment covering all aspects of the Mullaperiyar dam dispute.