Mullaperiyar Dam

Mullaperiyar Dam is a masonry gravity dam on the Periyar River. It is located 2,889 ft (881 m) above mean sea level on the Cardamom Hills of Western Ghats in Thekkadi, Idukki District of Kerala, India. It was constructed in 1895 by the British Government, to divert water eastwards to Madras Presidency area (the present-day Tamil Nadu). It has a height of 176 ft (54 m) from the foundation and length of 1,200 ft (366 m). The Periyar National Park, Thekkady is located around the dam's reservoir. The safety of the dam has been a matter of concern and a point of dispute between Kerala and Tamil Nadu States.

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. 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.

Design

The Mullaperiyar is a masonry gravity dam, which uses its weight and the forces gravity to support the reservoir weight and remain stable. 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 is comprised of a main dam section, spillway section on its left and an auxiliary (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.

History

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".

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. 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.

In May 1882, the construction of the dam began. As per "The Military Engineer in India" Vol II by Sandes (1935), the dam was constructed from concrete and masonry at a cost of Rs 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. Another source states that the dam was constructed of lime and surki (a mixture of sugar and calcium oxide), 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 Rs. 84.71 lakhs.

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 RS per year. When India became independent, the lease got 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 RS, and for the electricity generated in Lower Camp using Mullaperiyar water, the charge was 12 RS 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 Rs as tax per year for the whole land and 7.5 lakhs RS per year as surcharge for the total amount of electricity generated.

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.The lease provided the British the rights over "all the waters" of the Mullaperiyar and its catchment basin, for an annual rent of Rs. 40,000.

The National Register for Large Dams lists the Mullaperiyar dam as located in Kerala, but operated by Tamil Nadu .

The Lease Agreement

Safety ConcernsIn 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 . After Independence the areas downstream of the Mullaperiyar become heavily inhabited, as Kerala has a very high population density.

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 Factors

1. Age of the dam: The dam is 116 years old as of 2011. It has outlived its expected life span of 50 years. Strengthening the existing dam has its limitations and may not prove to be effective in the event of a disaster

2. Construction Material: The dam was constructed using lime and mortar. Seepage and leaks from the dam have caused concern.

3. Earthquakes: The dam is situated in a seismically active zone . CESS has reported that the dam cannot withstand earthquakes above 6 point on the Richter scale. Several earthquake tremors have occurred in the area in recent times. 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).

4. Changing weather patterns leading to incessant rains, flooding and overflow of the dam.

5. Insufficient or improper safety maintenance and safety monitoring of the dam

Potential adverse impact in the event of a disaster

1. Impact on lives and property downstream in the event of a disaster: The estimated population of the five districts of Kerala downstream is 3.5 million. Villages such as Vallakadavu, Vandiperiyar, Upputhara, Ayyappankoil, Kumili and parts of Kattappana and other parts of Idukki and Ernakulam Districts would be immediately affected, with loss of lives and property.

2. Impact on flora and fauna including endangered species such as tiger and elephants in the Periyar Wildlife Sanctuary.

3. Impact on tourism: Thekkady Reservoir and Periyar Wild Life Sanctuary are important and popular tourist spots in Kerala^{[citation needed]}.

4. Impact on Idukki Dam and the disastrous consequences of an Idukki Dam disaster.

5. Impact on agriculture, drinking water supply and power generation in southern Tamilnadu.

6. 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 area. One news article 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."

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).

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".

Current status

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).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.

Construction of a new dam

Kerala enacted the Kerala Irrigation and Water Conservation (Amendment) Act, 2006 to ensure safety of all dams in the State including the Mullaperiyar dam. The law empowered Kerala's Dam Safety Authority to oversee safety of dams in the State with powers to direct Tamil Nadu to suspend or restrict the functioning of the Mullaperiyar dam, to prevent submergence of land beyond the leased land; protect environment, flora and fauna; promote tourism and ensure the safety and security of its inhabitants.

In pursuance of Kerala's dam safety law, in September 2009, the Ministry of Environment and Forests of Government of India granted 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. 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 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. Tamil Nadu Chief Minister M. Karunanidhi said 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. However, Leader of Opposition J. Jayalalithaa objected to the TN Government move. She said that this would give advantage to Kerala in the issue. 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.^[31] 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. However, Supreme Court refused to accept Tamil Nadu's request to scrap the decision to form the empowered committee. SC also criticized the Union Government on its reluctance in funding the empowered committee.

TODAY

Thiruvananthapuram: With the standoff between Kerala and Tamil Nadu on the Mullaperiyar dam issue escalating, Kerala Chief Minister Oommen Chandy will meet Prime Minister Manmohan Singh here. Claiming that the Prime Minister was "already convinced" of the state's demand for a new dam in place of the 116-year-old structure, Chandy said after a Cabinet meeting that he would once again take up the matter with him.

Chandy said he would write to Tamil Nadu Chief Minister Jayalalithaa explaining Kerala's position on the Mullaperiyar issue. He sought to know why Jayalalithaa, who was opposing the Koodankulam Nuclear Power Project in Tamil Nadu on the safety issue, was reluctant to adopt the same yardstick in the Mullaperiyar issue where the safety of three million people was involved.