Mullaperiyar Dam

The Mullaiperiyar dam is a masonry gravity dam. Masonry means made of mortar. The dam is located in the state of Kerala. But the dam is operated and maintained by Tamil Nadu Government. It is constructed across Periyar river. The dam was constructed by John Pennycuick between 1887 and 1895.

About Mullaiperiyar Dam

The height of the dam is 53.6 metres. Its length is 365.7 metres. It is located at the confluence of Mullayar river and Periyar river. The catchment area of the Mullaiperiyar dam is in Kerala. According to a United Nations Report, the dam needs to be decommissioned. This is because, the dam is located in a seismically active area and it poses risk to 3.5 million people.

Purpose of the dam

The Periyar river flows westward into the Arabian sea. However, it was diverted eastward to provide water to the rain shadow regions (region with significantly less rainfall as it is located on the other side of the mountains) in Tamil Nadu, especially the Madurai city and its surroundings. The dam thus created the Periyar Thekkady reservoir. The water from the reservoir was diverted eastwards to augment the flow of Vaigai river (the major river of the Madurai city).

Design of the Dam

The dam is a gravity dam, meaning, it is made of concrete prepared from burnt brick powder and limestone.

Construction of the dam

The greatest challenge of the dam was to divert the river water so that the lower portions of the dam could be built. The coffer dams and the temporary embankments were washed away by the frequent floods and rains in the region. The British eventually stopped funding the dam. The Officer Pennycuick then raised money by selling the jewels of his wife and completed the work.

Periyar National Park

The Park is located around the reservoir of the dam. The Periyar National Park is a protected area of Kerala. It is also a protected tiger reserve. It has more than 35 tigers. In 2002, it was declared an elephant reserve. In 2005, there were around 1100 elephants in the reserve.

Dam Safety

After the Morvi Dam Failure in Gujarat in 1979, several safety concerns were raised against the aging Mullaiperiyar dam. The structure will not withstand an earthquake of magnitude 6 on Richter scale. The Tamil Nadu Government lowered the storage level of the dam twice. It was first reduced from 152 feet to 142.2 feet. Then it was reduced to 136 feet. This was done on the orders of the Central Water Commission.

Issue between Tamil Nadu Government and Kerala Government

In 1886, a lease agreement on Mullaiperiyar Dam was signed between the Maharaja of Travancore and the British Secretary of India. According to the agreement, a lease indenture of 999 years was made. With this, the British Government gained full power to construct and maintain the dam. After independence, Travancore-Cochin (later Kerala) reorganized as a state and the Madras Presidency reorganized as the Madras State (later Tamil Nadu). The dam is operated by the Tamil Nadu Government based on the agreement signed in 1886. The Kerala Government now wants to renew the agreement. According to the Kerala Government, the agreement is invalid.

Justice A.S. Anand Committee

The committee was constituted by the Supreme Court to study the issues of Mullaiperiyar dam. According to the committee, the dam is seismically and hydrologically safe.

Kerala on the issue

In 2006, the Kerala Government legislated the Kerala Irrigation and Water Conservation (Amendment) Act. Under the act, the state intended to ensure the safety of all the endangered dams. Also, the act listed Mullaiperiyar dam as an endangered dam. And eventually in 2009, the Kerala Government wanted to construct a new dam. The Tamil Nadu Government approached the Supreme Court and the stayed the construction.