Chennai: The Kerala government’s move to seek terms of reference (ToR) for an environmental impact assessment (EIA) study to build a new Mullaperiyar dam has caused the long-running row between the state and its neighbour, Tamil Nadu, to flare up again.
Kerala wants to build a new dam because of safety concerns over the existing 128-year-old structure. However, Tamil Nadu is concerned by this move as it believes a new dam will snatch away its rights to operate and maintain the structure, which is crucial for irrigation in several of its districts such as Madurai, Theni, Dindigul and Sivaganga.
Kerala has sought extension of the ToR to conduct an EIA study to build a new dam, James Wilson — a member of the Kerala government’s Mullaperiyar Special Cell from 2006 to 2017 and special officer, Inter State Water from 2017 to 2019 — told ThePrint.
Tamil Nadu Chief Minister M.K. Stalin has expressed strong opposition to this. In a letter to the Union Minister for Environment Bhupender Yadav, Stalin Friday urged the central government not to take up the matter for discussion during its expert appraisal committee (EAC) meeting on 28 May in New Delhi.
Stalin said that the existing dam had been found to be safe by expert committees and it was ruled to be so by the Supreme Court, and a move to conduct an EIA would be in contempt of court. The CM warned that his government would resort to “strict legal action” if both parties (Kerala and the Centre) didn’t adhere to the court orders.
Stalin’s letter came a day after political parties in Tamil Nadu including the Congress, the Pattali Makkal Katchi (PMK) and the Amma Makkal Munnetra Kazhagam (AMMK) made strong objections to the Kerala government’s move.
The Mullaperiyar dam in Kerala’s Idukki district, which is maintained and operated by Tamil Nadu, has always been a subject of dispute between the two states.
While the Tamil Nadu government has always pushed to raise the water level of the dam, Kerala has expressed apprehensions, citing safety concerns over the 128-year-old structure.
Kerala started pushing for a new dam in the existing Mullaperiyar project in 2009 but never succeeded in its attempt due to the opposition from its neighbour. The state’s Irrigation Design and Research Board had also prepared a detailed project report for a new dam in 2011.
According to regional media reports, the new dam will be completed in five years, at a cost of Rs 1,300 crore, if Tamil Nadu gives the nod for the project. The project is proposed to be built 366 metres downstream of the existing structure.
ThePrint reached the office of Kerala’s water resources department with queries on the subject, but the calls went unanswered. This report will be updated if and when a response is received.
Wilson said the EIA study was only meant for deliberations between Kerala and Tamil Nadu on whether a new dam would negatively affect the environment.
“Any construction activities to be done for a new Mullaperiyar dam require consensus from the Tamil Nadu government. That is very clear from the 2014 judgment of the Supreme Court. Conducting an EIA study doesn’t mean that the state is going ahead with the dam construction,” Wilson said, adding that Tamil Nadu political parties are taking up the issue as it is a sensitive matter.
Wilson further told ThePrint that the Kerala government has “only sought extension of the ToR granted in 2018 by the environment ministry for a period of four years for the EIA”.
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Kerala’s safety concerns, Tamil Nadu’s water woes
Constructed between 1887 and 1895, the Mullaperiyar dam is maintained by the Tamil Nadu government, according to an 1886 lease agreement signed between the Maharaja of Travancore and the Secretary of State for India for 999 years.
Though the dam lies in Kerala, it irrigates 68,558 ha area in Tamil Nadu through a tunnel to the Vaigai basin. The project is crucial for the water needs of Madurai and neighbouring districts such as Theni, Dindigul, Sivaganga and Ramanathapuram. The full reservoir level of the existing dam is 152 ft.
There have, however, been multiple concerns over the safety of the century-old dam as a minor earthquake reportedly caused cracks in its structure in 1979.
Local media reports suggest that the scare was also triggered by the Machchhu dam failure in the Morbi district of Gujarat the same year, which killed thousands of people.
The Kerala government in 2006 brought in IIT Delhi and IIT Roorkee to study the safety aspects of the dam. They concluded that the dam was vulnerable to seismic activity — an argument seen by Tamil Nadu as an excuse to build a new dam.
The Idukki district also experienced seismic tremors in 2011 and 2012, leading to more cracks and leaks in the structure, causing great panic among local residents and stirring up protests in Kerala.
In 2021, the dam was featured in a report series, Ageing Water Storage Infrastructure: An Emerging Global Risk by the United Nations University Institute for Water, Environment and Health, which analysed ageing dams. It said that “dam failure would be catastrophic as nearly 3.5 million people will be affected”.
Panic was also triggered two times when the water level of the reservoir crossed 142 feet in 2014 and later in 2018, when Kerala was hit by devastating floods.
The two states have also engaged in a legal battle over the water level multiple times.
In 2006, the Supreme Court permitted Tamil Nadu to raise the water level to 142 ft.
The Kerala government soon passed the Irrigation and Water Conservation (Amendment) Act, 2006, prohibiting raising the water level beyond 136 ft. The state also placed the dam in the category of ‘endangered dams’, a move that triggered Tamil Nadu to approach the apex court.
In 2009, Kerala mooted the idea of constructing a new dam as a feasible solution. Tamil Nadu objected to this and said it would take measures to strengthen the existing structure.
In its 2014 verdict on the issue, the Supreme Court declared the Kerala Irrigation and Water Conservation (Amendment) Act, 2006, unconstitutional. It directed the Centre to set up a committee to study the safety and storage level of the dam. The court also said a new dam could be constructed if Kerala and Tamil Nadu reached a consensus.
Apart from the Mullaperiyar issue, Tamil Nadu has an ongoing dispute with its neighbour in the north, Karnataka, over the release of the due share of water through the Cauvery river. There is also a decades-long conflict between Goa and Karnataka over the sharing of water of the Mahadayi river.
(Edited by Nida Fatima Siddiqui)
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