Mullaperiyar Dam

Syllabus: General Studies Paper 1

The Mullaperiyar Dam in Kerala was built on the Periyar river in 1895.

• The dam is located on the confluence of the Mullayar and Periyar rivers in Kerala’s Idukki district. The dam is located on the Cardamom Hills of the Western Ghats.
• The dam is located in Kerala but is operated and maintained by the neighbouring state of Tamil Nadu.
• The dam is operated by Tamil Nadu following an 1886 lease agreement for 999 years. It was signed between the Maharaja of Travancore and the Secretary of State for India during British Rule.
• In the 1970s, the lease agreement was renewed by Tamil Nadu and Kerala. It gave the former, rights to the water from the dam, besides the authority to develop hydropower projects at the site. In return, Kerala receives rent from Tamil Nadu.

Periyar River

• The Periyar River is the longest river in the state of Kerala with a length of 244 km.
• It is also known as ‘Lifeline of Kerala’ as it is one of the few perennial rivers in the state.
• Periyar River originates from Sivagiri hills of Western Ghats and flows through the Periyar National Park.
• The main tributaries of Periyar are Muthirapuzha, Mullayar, Cheruthoni, Perinjankutti.

United Nations University-Institute for Water, Environment and Health (UNU-INWEH) has released a report titled “Ageing Water Storage Infrastructure: An Emerging Global Risk”. The report provides an overview of the current state of knowledge on the ageing of large dams.

• The report says the dam is located in a seismically active area, making it prone to earthquakes. The intended lifespan of the dam is 50 years.
• A minor earthquake caused cracks in the dam in 1979, and in 2011, more cracks appeared in the dam due to seismic activity. It warns that in case of a catastrophe, 3.5 million people would be in danger.
• Consequently, the Central Water Commission decided that water level in the dam be brought down from the full reservoir level of 152 ft to 136 ft. It will enable Tamil Nadu to carry out dam strengthening works.
• By the 1990s, Tamil Nadu started demanding restoration of the water level in the Mullaperiyar dam as it completed the task assigned to it. When no consensus was reached through negotiations, the Supreme Court was approached.