Angering Kerala, Tamil Nadu on Monday opened nine shutters of the Mullaperiyar Dam in view of the rising water level in the reservoir and shut down three of them after 10 PM. Terming the move as ‘irresponsible’ the Kerala government said that it resulted in the inundation of a few areas and the state will approach the Supreme Court.
The district administration said nine shutters of the dam, which were initially opened at 7.45 pm by 60 centimeters each, were raised by 120 cm (1.20m) to release 12654.09 cusecs of water. Thereafter, three of the shutters were shut down at 10.00 PM and six were kept open to release 8380.50 cusecs of water, it said.
Kerala said that the move was unexpected as it repeatedly appealed to the Tamil Nadu government to not open the shutters at night. Kerala water resources minister Roshy Augustine told Hindustan Times (HT), since the released water will move to Idukki, the Idukki dam will also be opened on Tuesday morning. ‘The move was least expected,’ she added.
The dam is the cause of a decades-old dispute between the two states. Tamil Nadu which owns and runs the Mullaperiyar dam, is against the rebuilding of the dam fearing it will lose control over it.
What is the Mullaperiyar Dam Issue?
The Mullaperiyar dam, built-in 1895 on the Periyar river in the Idukki district of Kerala, is operated by the Tamil Nadu government for its irrigation and power needs.
The dam is located in the upper reaches of the river Periyar, which flows into Kerala after originating in Tamil Nadu. The reservoir is within the Periyar Tiger Reserve and the water diverted from the reservoir is first used for power generation in lower Periyar (by Tamil Nadu) before flowing into the Suruliyar, a tributary of the Vaigai river, and then for irrigating nearly 2.08 lakh hectares in Theni and four other districts farther away.
Safety concerns around the dam date back to the early 1960s, when media reported it was unsafe. Kerala brought up the issue before the Central Water Commission in 1961. After a joint inspection by Kerala and Tamil Nadu in 1964, the water level was reduced for the first time, from 155 ft to 152 ft. Meanwhile, in the following years, Tamil Nadu witnessed several public agitations demanding that the level should be increased and Kerala opposed the demand.
When the state governments failed to negotiate, several petitions were filed in the High Courts of both the states. These were subsequently transferred to the Supreme Court. In 2000, the Centre appointed an expert committee to look into safety and suggest storage levels. However, in 2006, SC allowed Tamil Nadu to raise the water level to 142 ft and added that the level should be increased only after completing strengthening work. The level could be restored to 152 ft if an expert committee examined and recommended it.
In March 2006, the Kerala Assembly amended the Kerala Irrigation and Water Conservation Act, 2003, bringing Mullaperiyar in the schedule of ‘Endangered Dams’ and restricting its storage at 136 ft. Since then, the issue has shifted to the safety of the dam. Meanwhile, in 2007, the Kerala Cabinet permitted preliminary work on a new dam. Tamil Nadu approached the Supreme Court against the move and in 2010, the SC formed an empowered committee to look into the dam’s safety. However, in 2012, the SC rejected Kerala’s plea to bring on record data from its committee of experts from IIT Delhi and IIT Roorkee, to counter the expert committee’s report citing the dam structure as safe.
The Supreme Court in October 2021 ordered that the court-appointed supervisory committee had suggested 139.50 ft as the permissible level and it directed that both states to go by the committee’s recommendation. Tamil Nadu had wanted the level increased to 142 ft as fixed by the Supreme Court in 2014, while Kerala wanted it within 139 ft as per a rule curve fixed until the end of the month.