Mullaperiyar Dam is a masonry gravity dam on thePeriyar River.[1][2][4] It is located 881 m (2,890 ft) above mean sea level on the Cardamom Hills of Western Ghats in Thekkadi, Idukki District of Kerala, India. It was constructed between 1887 and 1895 by the British Government to divert water eastwards to Madras Presidency area (the present-day Tamil Nadu). It has a height of 53.6 m (176 ft) from the foundation and length of 365.7 m (1,200 ft).[1] The Periyar National Park,Thekkady is located around the dam's reservoir. Eventhough the dam and the river are fully owned by and located in Kerala [1], the dam is controlled and operated on a period lease by Tamil Nadu[1]. The safety of the dam has been a matter of concern and a point of dispute between Kerala and Tamil Nadu States.
Etymology
Earlier known as the Periyar dam as it was basically meant to dam the Periyar river,[5] the present nameMullaperiyar is derived from a portmanteau of Mullayar and Periyar, at the confluence of which the dam is located below.[6]
Purpose
The geography of the Periyar river which flows westward into the Arabian Sea had suggested to engineers in the first decade of the nineteenth century that the river waters could be diverted eastward to flow towards the Bay of Bengal and provide water to the arid Madurai region of Madras Presidency which was in dire need for a greater supply than the small Vaigai River could give.[5] The dam, finally constructed in 1895, created the Periyar Thekkady reservoir, from which water was diverted eastwards to Tamil Nadu via a tunnel enabling the water to join the Vaigai River which was dammed to provide a source for irrigating large tracts of Madurai. Initially the dam waters were used only for irrigation. Later, the Periyar Power Station in Lower Periyar, Tamil Nadu was built which generates hydro-electricity from the diverted waters.[7]
Design
The Mullaperiyar Dam is a gravity dam made with limestone and surkhi (a mixture of sugar and calcium oxide). Gravity dams use their weight and the force of gravity to support the reservoir and remain stable.[2][4] The main dam has a maximum height of 53.6 m (176 ft) and length of 365.7 m (1,200 ft). Its crest is 3.6 m (12 ft) wide while the base has a width of 42.2 m (138 ft). It consists of a main dam,spillway on its left and an auxiliary dam (or "baby dam") to the right. Its reservoir can withhold 443,230,000 m3 (359,332 acre·ft) of water, 299,130,000 m3(242,509 acre·ft) of which is active (live) storage.[3][2]
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Dam construction
The location of the dam had first been scouted by Captain J. L. Caldwell, Madras Engineers (abbreviated as M.E.) in 1808 to reconnoitre the feasibility of providing water from the Periyar river to Madurai by a tunnel through the mountains. Caldwell discovered that the excavation needed would be in excess of 100 feet in depth and the project was abandoned with the comment in his report as "decidedly chimerical and unworthy of any further regard".[5]
The first attempt at damming the Periyar with an earthen dam in 1850 was given up due to demands for higher wages by the labour citing unhealthy living conditions.[4] The proposal was resubmitted a number of times and in 1862, Captain J. G. Ryves, M.E., carried out a study and submitted proposals in 1867 for another earthwork dam, 62 feet high. The matter was debated by the Madras Government and the matter further delayed by the terrible famine of 1876-77. Finally, in 1882, the construction of the dam was approved and Major John Pennycuick, M.E., placed in charge to prepare a revised project and estimate which was approved in 1884 by his superiors.[5]
In May 1887, construction of the dam began. As per "The Military Engineer in India" Vol II by Sandes (1935), the dam was constructed from lime stone and surkhi (burnt brick powder and a mixture of sugar and calcium oxide, one of the archaiced construction techniques of 19th century) [4] at a cost of₹ 104 lakhs, was 173 feet high and 1241 feet in length along the top and enclosed more than 15 thousand million cubic feet of water.[5] Another source states that the dam was constructed of concrete (no real evidence or reference for this) and gives a figure of 152 feet height of the full water level of the reservoir, with impounding capacity of 10.56 thousand million cubic feet along-with a total estimated cost of ₹ 84.71 lak.[5]
The dam created a reservoir in a remote gorge of the Periyar river situated 3,000 feet above the sea in dense and malarial jungle, and from the northerly arm of this manmade waterbody, the water flowed first through a deep cutting for about a mile and then through a tunnel, 5704 feet in length and later through another cutting on the other side of the watershed and into a natural ravine and so onto the Vaigai River which has been partly built up for a length of 86 miles, finally discharging 2000 cusecs of water for the arid rain shadow regions of present-day Theni, Madurai District, Sivaganga District andRamanathapuram districts of Tamil Nadu, then under British rule as part of Madras Province (Sandes, 1935).[5]
The Periyar project, as it was then known, was widely considered well into the 20th Century as "one of the most extraordinary feats of engineering ever performed by man".[5] The greatest challenge was the diversion of the river so that lower portions of the great dam could be built. The temporary embankments and coffer-dams used to restrain the river waters were regularly swept away by floods and rains. An extremely large amount of manual labour was involved and the mortality of the workers from malaria was extremely high. It was claimed that had it not been for "the medicinal effects of the native spirit called arrack, the dam might never have been finished".[5] The construction also involved the use of troops namely, the 1st and 4th battalions of the Madras Pioneers as well as Portuguesecarpenters from Cochin who were employed in the construction of the coffer-dams and other structures.[5]
Lease
On 29 October 1886, a lease indenture for 999 years was made between Maharaja of Travancore, Vishakham Thirunal and Secretary of State for India for Periyar irrigation works. The lease agreement was signed by Dewan of Travancore V Ram Iyengar and State Secretary of Madras State (under British rule) J C Hannington. This lease was made after constant pressure on Travancore King by the British for 24 years. The lease indenture inter alia granted full right, power and liberty to construct, make and carry out on the leased land and to use exclusively when constructed, made and carried out all such irrigation works and other works ancillary thereto to Secretary of State for India (now Tamil Nadu). The agreement was to give 8000 acres of land for the reservoir and another 100 acres to construct the dam. And the tax for each acre was ₹ 5 per year. When India became independent, the lease agreement expired. After several failed attempts to renew the agreement in 1958, 1960, and 1969, the agreement was renewed in 1970 when C Achutha Menon was Kerala Chief Minister. According to the renewed agreement, the tax per acre was ₹ 30, and for the electricity generated in Lower Camp using Mullaperiyar water, the charge was ₹ 12 per kiloWatt per hour. Tamil Nadu uses the water and the land, and the Tamil Nadu government has been paying to the Kerala government for the past 50 years ₹ 2.5 lakhs as tax per year for the whole land and ₹ 7.5 lakhs per year as surcharge for the total amount of electricity generated.[7]
Although Kerala claims that the agreement was forced on the then princely State of Travancore, presently part of Kerala, the pact was re-validated in 1970 by Kerala and Tamil Nadu.[8] The lease provided the British the rights over "all the waters" of the Mullaperiyar and its catchment basin, for an annual rent of ₹ 40,000.
Biodiversity
According to a report by the Kerala Forest Research Institute, the reserve surrounding the dam is considered as a biodiversity hot spot.[9]
Disputes
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The dam is operated by the Government of Tamil Nadu based on a lease agreement entered into in 1886 by the British India Government and the Maharajah of Travancore. Control of the dam and the reservoir by Tamil Nadu, after Independence and after Reorganization of States, has been a matter of dispute between the States of Kerala and Tamil Nadu. The matter is still sub judice and is currently pending before a Division Bench of the Supreme Court.[10][11][12]
The Lease Agreement
A lease deed was signed between the Travancore Princely State and British Presidency of Madras in 1886 which gave the British the right to divert "all the waters" of the Mullaperiyar and its catchment to British territory (the Madras Presidency, now Tamil Nadu) for 999 years.[13] After Independence, both the entities became non-existent. Further, according to Indian Independence Act 1947, all the treaties between British Government and Indian Princeley States have lapsed. Moreover, Article 131 of theConstitution of India denies Supreme Court of jurisdiction on pre-constitutional agreements.[14] Kerala argued that the agreement is not an equal one, but imposed on the local King by the British Empire.
In 1970 the Kerala and Tamil Nadu governments signed a formal agreement to renew the 1886 treaty almost completely[citation needed]. The Idukki Hydroelectric project, located 30 km downstream was completed in 1976 by the Kerala government [15] After Independence the areas downstream of the Mullaperiyar become heavily inhabited, as Kerala has a very high population density.
Safety Concerns
In 1979, safety concerns were raised by Kerala Government after an earthquake, that resulted in leaks and cracks in the dam. A state agency, Centre for Earth Science Studies (CESS), Thiruvananthapuram, 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.
Current safety concerns hinge mainly around the issues listed below:
Risk /Threat Factors
Risk /Threat Factors
- Age of the dam: The dam is 116 years old as of 2011. It has outlived its expected life span of 50 years [16][7]. Strengthening the existing dam has its limitations and may not prove to be effective in the event of a disaster (reference: Morvi Dam)[17]
- Construction Material: The dam was constructed using lime and mortar and archaiced 19th century construction techniques. Seepage and leaks from the dam have caused concern[18].
- Earthquakes: The dam is situated in a seismically active zone [19]. CESS has reported that the dam cannot withstand earthquakes above 6 point on the Richter scale[citation needed]. An earthquake measuring 4.5 on the Richter scale occurred on June 7, 1988 with maximum damage in Nedumkandam and Kallar (within 20 kms of the dam). Several earthquake tremors have occurred in the area in recent times. These could be reservoir-induced seismicity, requiring further studies according to experts.[20]
- Changing weather patterns leading to incessant rains, flooding and overflow of the dam[citation needed].
- Inadequate safety maintenance and safety monitoring of the dam
Potential adverse impact in the event of a disaster
- Loss of human life and property
- Impact on flora and fauna including endangered species such as tiger and elephants in thePeriyar Wildlife Sanctuary.
- Impact on tourism: Thekkady Reservoir and Periyar Wild Life Sanctuary are important and popular tourist spots in Kerala[citation needed].
- Impact on Idukki Dam and the disastrous consequences of an Idukki Dam disaster[citation needed].
- Impact on agriculture, drinking water supply and power generation in southern Tamilnadu.
- Impact of a disaster on the general economy of Kerala and Tamilnadu.
Tamil Nadu's stand
The Tamil Nadu government had increased its withdrawal from the reservoir, with additional facilities to cater to the increased demand from newly irrigated areas.[citation needed] One news article[21]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 ₹ 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."
The Kerala Government maintains that this is not true. During the year 1979–80 the gross area cultivated in Periyar command area was 171,307 acres (693.25 km2). After the lowering of the level to 136 ft (41 m), the gross irrigated area increased and in 1994–95 it reached 229,718 acres (929.64 km2).[22]
An article written in a 2000 Frontline magazine stated: "For every argument raised by Tamil Nadu in support of its claims, there is counter-argument in Kerala that appears equally plausible. Yet, each time the controversy gets embroiled in extraneous issues, two things stand out: One is Kerala's refusal to acknowledge the genuine need of the farmers in the otherwise drought-prone regions of Tamil Nadu for the waters of the Mullaperiyar; the other is Tamil Nadu's refusal to see that it cannot rely on or continue to expect more and more from the resources of an other State to satisfy its own requirements to the detriment of the other State. A solution perhaps lies in acknowledging the two truths, but neither government can afford the political repercussions of such a confession".[23]
Current status
Tamil Nadu is the custodian of the dam and its surrounding areas. In 2006, the Supreme Court of India by its decision by a single bench, allowed for the storage level to be raised to 142 feet (43 m).[24] However, the Kerala Governmentpromulgated a new "Dam Safety Act" against increasing the storage level of the dam, which has not been objected by the Supreme Court. Tamil Nadu challenged it on various grounds. The Supreme Court issued notice to Kerala to respond; however, did not stay the operation of the Act even as an interim measure. The Court then advised the States to settle the matter amicably, and adjourned hearing in order to enable them to do so. The Supreme Court[25] of India termed it as not unconstitutional. Meanwhile, the Supreme Court constituted a Constitution bench to hear the case considering its wide ramifications. The case involves pre-constitutional agreement between two entities which does not exist now.
Kerala's Stance: Kerala did not object giving water to Tamil Nadu. Their main cause of objection is the dams safety as it is as old as 110 years. Increasing the level would add more pressure to be handled by already leaking dam.
Tamil Nadu's Stance: The State wants that the 2006 order of Supreme court be implemented so as to increase the water level to 142 feet (43 m).
Construction of a new dam
Kerala enacted the Kerala Irrigation and Water Conservation (Amendment) Act, 2006[26] [27] to ensure safety of all 'endangered' dams in the State, listed in the second schedule to the Act. Section 62A of the Act provides for listing in the schedule, "details of the dams which are endangered on account of their age, degeneration, degradation, structural or other impediments as are specified". The second schedule to the Act lists Mullaperiyar (dam) constructed in 1895 and fixes 136 feet as its maximum water level. The Act empowers Kerala Dam Safety Authority (Authority specified in the Act) to oversee safety of dams in the State and sec 62(e) empowers the Authority to direct the custodian (of a dam) "to suspend the functioning of any dam, to decommission any dam or restrict the functioning of any dam if public safety or threat to human life or property, so require". The Authority can conduct periodical inspection of any dam listed in the schedule.
In pursuance of Kerala's dam safety law, in September 2009, the Ministry of Environment and Forests of Government of India granted[28] environmental clearance to Kerala for conducting survey for new dam downstream. Tamil Nadu approached Supreme Court for a stay order against the clearance; however, the plea was rejected. Consequently, the survey was started in October, 2009.
Justice A.S. Anand Committee
On 18 February 2010, the Supreme Court decided to constitute a five-member empowered committee to study all the issues of Mullaiperiyar Dam and seek a report from it within six months.[29] The Bench in its draft order said Tamil Nadu and Kerala would have the option to nominate a member each, who could be either a retired judge or a technical expert. The five-member committee will be headed by former Chief Justice of India A. S. Anand to go into all issues relating to the dam's safety and the storage level. However, the then ruling party of Tamil Nadu, DMK, passed a resolution that it not only oppose the apex court's decision to form the five-member committee, but also said that the state government will not nominate any member to it.[30] The then Tamil Nadu Chief Minister M. Karunanidhisaid that immediately after the Supreme Court announced its decision to set up a committee, he had written to Congress president asking the Centre to mediate between Kerala and Tamil Nadu on Mullaperiyar issue.[31] However, the then Leader of Opposition i.e., the present Chief Minister of Tamilnadu J. Jayalalithaa objected to the TN Government move. She said that this would give advantage to Kerala in the issue.[32] Meanwhile, Kerala Water Resources Minister N. K. Premachandran told the state Assembly that the State should have the right of construction, ownership, operation and maintenance of the new dam, while giving water to Tamil Nadu on the basis of a clear cut agreement. He also informed the media that Former Supreme Court Judge Mr. K. T. Thomas will represent Kerala on the expert panel constituted by Supreme Court.[33] On 8 March 2010, in a fresh twist to the Mullaperiyar Dam row, Tamil Nadu told the Supreme Court that it was not interested in adjudicating the dispute with Kerala before the special “empowered” committee appointed by the apex court for settling the inter-State issue.[34] However, Supreme Court refused to accept Tamil Nadu's request to scrap the decision to form the empowered committee. The Supreme Court also criticized the Union Government on its reluctance in funding the empowered committee.[35]
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