History, Issues and Controversies of Mullaperiyar Dam

Mullaperiyar Dam is a concrete-made gravity dam on the Periyar River in Kerala. It is situated 881 m above sea level in Thekkady, Kerala’s Idukki District in the Cardamom Hills of the Western Ghats. John Pennycuick built it between 1887 and 1895 and also acquired an arrangement to send water eastward to the Tamil Nadu state. The dam is built on the river Periyar in Kerala, and however, it is monitored and managed by the neighbouring state of Tamil Nadu. The catchment basin of the Mullaperiyar Dam is completely within Kerala, making it an intra-state river. For the first time in 35 years, the Mullaperiyar dam water level reached 142 feet on November 21, 2014. Following heavy rains in Kerala, the reservoir reached its maximum capacity of 142 feet on August 15, 2018. So there is a question about the dam’s safety, and there is an internal controversy between Kerala and Tamil Nadu states.

History of Mullaperiyar Dam:

The dam’s construction began in 1887 and was completed in 1895. According to an arrangement reached in October 1886 between the Maharaja of Travancore and the Presidency, 8,000 acres of land were leased to the latter to build the dam. The lease was for 999 years, with the option to extend for 999 years. The dam was built to divert a portion of the Periyar river, which caused flooding in Kerala, to the drought-prone Vaigai river basin in Tamil Nadu. Under Scottish Major John Pennycuick, the project started.

Following independence, Kerala and Tamil Nadu state maintained the dam system. After that Kerala Government said, the previous contract between the British raj and Travancore was invalid and needed to be rectified. After several failed attempts in 1970, the agreement was renewed. According to this renewed contract, the per acre tax of the dam’s land increased, and electricity generation costs increased for Tamilnadu.

Dispute Between Kerala and the Tamil Nadu States: 

Kerala has criticised the 1886 leasing deal and has contested its legality. However, the threat presented by the 126-year-old dam’s safety to Kerala residents in the case of a dam failure has been debated since 2009.

Tamil Nadu has contested Kerala’s proposal to decommission the dam and build a new one. Tamil Nadu has faulted Kerala for delaying finalising the dam’s rule curve.

• The rule curve determines the varying storage levels in a reservoir in a dam. The rule curve governs the timing of dam gate openings, and it is part of the dam’s safety system
• The rule curve level is established to avoid emergency dam shutter opening in the event of a flood-like situation. It aids in managing the Mullaperiyar dam water level during the monsoon season

Kerala has made repeated efforts to prevent Tamil Nadu from running the dam since Tamil Nadu cannot access data in Kerala’s terrain. There is no road, and the electricity supply has not been restored, even though Tamil Nadu has paid for it. Kerala has accused Tamil Nadu of using an “outdated” gate operation schedule in 1939

Supreme Court Judgements:

2006: The Supreme Court issued a three-member division bench judgement permitting the reservoir level to be raised to 142 feet (43 m) pending completion of the suggested reinforcing measures, installation of extra vents, and execution of other proposals.

• Kerala had no objections to providing water to Tamil Nadu. Their biggest concern is the dam’s safety, given it is almost 110 years old (in 2006). Increasing the Mullaperiyar dam water level would strain the already leaky dam.
• Tamil Nadu wants the Supreme Court’s 2006 ruling to raise the water level to 142 feet to be executed

2014: The Supreme Court of India deemed the Kerala Irrigation and Water Conservation (Amendment) Act, 2006 invalid, allowing Tamil Nadu to increase the Mullaperiyar dam water level from 136 feet to 142 feet, establishing a permanent Supervisory Committee to oversee the dam’s safety concerns.

Conclusion:

After the floods in Kerala in 2018 and the collapse of the Rishiganga hydro power plant and Tapovan dam in Uttarakhand due to a glacier burst that killed over 200 people, public concern about the Mullaperiyar dam’s safety reappeared in 2021.

According to a UN analysis of the hazards posed by ageing dams worldwide, the Mullaperiyar dam, located in a seismically active location, has serious structural problems, and 5 million people are at risk if the 100 -year-old dam fails.

Two applications were filed in the Supreme Court complaint alleging that the supervisory committee established by Supreme Court order in 2014 had not been working effectively for the past six years, to which the Supreme Court responded by ordering the Chief Secretary of Tamil Nadu to issue the rule curve instantly or face action.