Mullaperiyar Dam Dispute

GS Paper – 1: Water Resources

GS Paper – 3: Disaster Management, Infrastructure

Where the Dam is Located?

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.
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.

What is the Historical Dispute?

In 1886, the then Maharaja of Travancore signed the ‘Periyar Lease Deed’ with the British government, which considered the Periyar waters useless to Travancore.
It wanted to divert the water into the arid regions of Tamil Nadu.
The Maharaja signed the agreement after 20 years of resistance.
In 1895, the dam was constructed.
The Madras government started hydel power generation in 1959.
Safety concerns around the dam date back to the early 1960s, when the 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.
In the years that followed, Tamil Nadu witnessed public agitations demanding that the level be increased; Kerala opposed the demand.

What is the Current Dispute?

There has been unusual rains in the last couple of weeks in this region, which have led to the water level inching towards its permissible level of 142 ft.
When it reached 138.15 ft. Kerala had wanted the level fixed at 136 ft, but the Supreme Court in 2014 allowed Tamil Nadu to raise it to 142 ft. as per a rule curve fixed until the end of the month.
Meanwhile, the Supreme Court order has come after a court-appointed supervisory committee had suggested 139.50 ft as the permissible level. The court has directed 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.
This time, while seeking a limit of 139 ft, Kerala pointed to a Supreme Court directive in August 2018 following the devastating floods in the state. One of the factors contributing to the floods was sudden discharge from the Mullaperiyar dam after its water level went beyond 142 ft and all spillway shutters of the dam suddenly lifted.
The situation in 2021 is not different, claims the Kerala government. The Idukki reservoir, which is in the same district as the Mullaperiyar dam, was at 94% of its live storage capacity.

Way Forward

Kerala has been demanding a new dam replacing the existing one, and located 366 ft downstream.
While Kerala Governor Arif Mohammed Khan recently expressed his support to the idea, such a project would need the consent of Tamil Nadu.
The construction of a new dam would also give rise to a demand for a new water-sharing treaty; at present, only Tamil Nadu has rights over the dam water.