Mullaperiyar Dam

Mullaperiyar Dam, a view from the Periyar Reservoir

Mullaperiyar Dam is constructed over the headwaters of the Periyar River river in Kerala, India. The Periyar National Park, Thekkady is located around the Periyar reservoir formed by the backwaters of this dam. Although the dam is owned by Kerala and situated at Thekkadi in Kerala, it is operated by the Government of Tamil Nadu according to a 999-year lease agreement made during erstwhile British colonial rule.

Name

The name is derived from a portmanteau of Mullayar and Periyar. As the dam is located after the confluence of the Mullayar and Periyar Rivers, the river and hence the dam came to be called Mullaperiyar^[1]^[2].

History

The structure was conceived by the British during the colonial rule to divert the waters of the west-flowing Periyar River eastwards, through the construction of a masonry dam, and taking the water from the reservoir through a tunnel cut across the watershed and Western Ghats to the arid rain shadow regions of Theni, Madurai District, Sivaganga District and Ramanathapuram districts of Tamil Nadu^[3] . The Princely State of Travancore ^[4] was forced ^[5] to sign a treaty in 1886 in this regard to lease the dam site for 999 years to the then Madras government. The lease provided the British the rights over "all the waters" of the Mullaperiyar and its catchment, for an annual rent of Rs. 40,000.

The dam was built by the British Army Engineering corps for the Travancore kingdom. The first dam was washed away by floods, and a second masonry dam was constructed in 1895.

Disputes

The government of Tamil Nadu has proposed an increase in the storage level of the dam from the currently maintained 136 feet to 142 feet. The Kerala government has opposed this move, citing safety concerns for the more than hundred year old bridge and especially for the thickly populated districts downstream.

Historical background of the dispute

After Indian independence, the states were reorganised and the area surrounding the location of the dam was merged with Kerala State. Tamil Nadu continued to use the water from Periyar for extending irrigation facilities , and later for power generation ^[6] on the basis of informal agreements between the governments of the two states. In 1970 the Kerala and Tamil Nadu governments signed a formal agreement to renew the 1886 treaty almost completely. The Idukki Hydroelectric project, located 30 km downstream was completed in 1976 by the Kerala government, is still the major resource for irrigation and electricity needs of Kerala. After Independence the areas downstream of the Mullaperiyar had started to become heavily inhabited. In 1979, safety concerns were raised by Kerala Government after a minor earthquake, after which a few leaks were detected in the Mullaperiyar dam. A state agency ^[7] had reported that the structure would not withstand an earthquake above magnitude 6 on the Richter scale. The then Tamil Nadu government lowered the storage level to the current 136 feet (from 142.2 feet) at the request of the Kerala Government to carry out safety repairs, after which it was suggested that the storage level could be raised to the full reservoir level of 152 feet. Meanwhile the storage levels in the new Idukki dam were not sufficient for the hydroelectric project to work to its full capacity due to insufficient inflow from its catchment areas. Security concerns regarding the downstream inhabitants prompted Kerala to backtrack on the 1970 Agreement in 2000. Another argument put forward by Kerala on the basis of a report on a study conducted state agencies ^[8] suggested that the loss of habitat to the fauna of Periyar National Park would occur due to flooding after the increase in the storage level.

Meanwhile, the Tamil Nadu government had increased its withdrawal from the reservoir, with additional facilities to cater to the increased demand from newly irrigated areas. One article ^[9] estimates that "the crop losses to Tamil Nadu, because of the reduction in the height of the dam, between 1980 and 2005 is a whopping Rs. 40,000 crores. In the process the farmers of the erstwhile rain shadow areas in Tamil Nadu who had started a thrice yearly cropping pattern had to go back to the bi-annual cropping."

However, the Kerala Government maintains that this is not true. During the year 1979-80 the gross area cultivated in Periyar command area was 171307 acres. After the lowering of the level to 136ft, the gross irrigated area increased and in 1994-95 it reached 2,29,718 acres. ^[10]

Current status

Tamil Nadu is the custodian of the dam and its surrounding areas. The Supreme Court of India has allowed for the storage level to be raised to 142 feet. ^[11] A recent law, promulgated by the Kerala government against increasing the storage level has not been objected ^[12] to by the Supreme Court^[13] of India, which termed it as not unconstitutional.

Notes

^ which now does not exist as a river as it is part of the backwater/reservoir.
^ The main river is called the Periyar River.
^ Which were under British rule as part of Madras Province.
^ Presently part of Kerala, was a protectorate under the British rule at that time.
^ R. Krishnakumar, Frontline, Volume 23 - Issue 05, Mar. 11 - 24, 2006.
^ In 1959.
^ CESS, Centre for Earth Science Studies, Thiruvananthapuram
^ A study on the impact of raising of water level in the Mullaperiyar reservoir of the Periyar Tiger Reserve was carried out by scientists from the Kerala Forest Research Institute (KFRI), the Tropical Botanic Garden and Research Institute (TBGRI), Centre for Water Resource Development and Management (CWRDM) and the Salim Ali Centre for Ornithology and Natural History (SACON)
^ E Gopinath
^ Kerala Government's arguments
^ News in Deccan Herald
^ The Supreme Court has not "objected" to the Dam Safety Act passed by Kerala Legislature. Tamil Nadu has challenged it on various grounds. The Supreme Court has issued notice to Kerala to respond; However, the Hon'ble Court REFUSED to stay the operation of the Act even as an interim measure, as requested by Tamil Nadu. The Hon'ble Court advised the States to settle the matter amicably, and adjourned hearing in order to enable them to do so.
^ The Hindu, September 9, 2006