The Supreme Court recently ordered the Mullaperiyar Dam Supervisory Committee to issue directions on issues concerning the dam’s safety. The SC constituted a permanent Supervisory Committee in 2014 to oversee all the issues concerning Mullaperiyar dam. The dam is a source of friction between Tamil Nadu and Kerala.
Mullaiperiyar Dam is a masonry gravity dam on the Periyar River in the Indian state of Kerala.
It is located 881 m above mean sea level, on the Cardamom Hills of the Western Ghats in Thekkady, Idukki District of Kerala, South India.
It was constructed between 1887 and 1895 by John Pennycuick and also reached in an agreement to divert water eastwards to the Madras Presidency area.
The dam is built at the confluence of Mullayar and Periyar rivers. The dam is located in Kerala on the river Periyar, but is operated and maintained by the neighbouring state of Tamil Nadu.
Although the Periyar River has a total catchment area of 5398 km2 with 114 km2 downstream from the dam in Tamil Nadu, the catchment area of the Mullaperiyar Dam itself lies entirely in Kerala and thus not an inter-State river.
However, by the principle of estoppel it is considered otherwise. On 21 November 2014, the water level hit 142 feet for first time in 35 years. The reservoir again hit the maximum limit of 142 feet on 15 August 2018, following incessant rains in the state of Kerala.
The Periyar River is the longest river in the state of Kerala with a length of 244 km. Periyar is also the name given to a lake in the river's course.
The river, 140 miles (225 km) long, rises in the Western Ghats range near the border with Tamil Nadu state and flows north a short distance to Periyar Lake.
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.
It is one of the few perennial rivers in the region and provides drinking water for several major towns. The Periyar is of utmost significance to the economy of Kerala.
It generates a significant proportion of Kerala's electrical power via the Idukki Dam and flows along a region of industrial and commercial activity.
The dam was built in the late 1800s in the princely state of Travancore (present-day Kerala) and given to British-ruled Madras Presidency on a 999-year lease in 1886.
The agreement granted full rights to the secretary of state of Tamil Nadu, a British official, to construct irrigation projects on the land.
The dam was built to divert eastwards a part of the west-flowing Periyar river, to feed the arid areas of Tamil Nadu.
The agreement was renewed by the two state governments in independent India in the 1970s.
Tamil Nadu was given rights to the land and the water from the dam as well as the authority to develop hydro-power projects at the site, and Kerala would receive rent in return.
However, safety concerns surfaced in 1979 after reports in the Kerala press claimed a minor earthquake had caused cracks in the dam.
Tamil Nadu claims that though it has undertaken periodic repairs on the dam, the Kerala government has not allowed it to raise the water level.
It says it has suffered huge losses from not being able to use the dam to its full capacity.
Kerala, on the other hand, contends it is not safe to raise the water level as Idukki district, where the dam is located, is earthquake-prone and has experienced multiple low-intensity quakes.
Scientists, too, have said the dam cannot withstand an earthquake measuring over six on the Richter scale and that if such a calamity were to happen, the lives of more than three million people would be imperilled.
