The Mullaperiyar dam debate - An issue of safety versus rights?

The issue that has been making headlines in the last few days has been that of the continuing debate between the states of Kerala and Tamil Nadu over the Mullaperiyar dam. This debate has opened  up a number of issues related to the ownership and use of water between the two states of Tamil Nadu and Kerala in the context of the current changes and the loss of relevance of the laws and decisions made during the colonial rule; the water sharing, irrigation and power generation needs of both the states; and the recent concerns on the safety of the dam in Kerala versus the urgent irrigation needs of the agricultural sector in Tamil Nadu.

Mullaperiyar dam

A view of the Mullaiperiyar dam on Kerala-Tamil Nadu border at Kumili.Photo: Vibhu

Image Source: The Hindu

This article sheds light on the history of the Mullaperiyar dam and the background for the current deadlock between the two states over the dam. The current deadlock between the two states over the dam is essentially not a dispute for water, but has its roots in the colonial times, and has to do with the need to come to terms with the agreements and decisions made in those times with changing economic, political and environmental contexts and concerns about the safety of the dam in Kerala versus the irrigation needs of the farmers in the state of Tamil Nadu.

The history behind the construction of the Mullaperiyar dam

This dam was earlier known as the Periyar dam and the present name Mullaperiyar is derived from a blending together of the names of two areas, Mullayar and Periyar, at the confluence of which the dam is located [2].The history of the construction of the dam goes back to the colonial times when a need was identified to divert the waters of the Periyar river eastward to flow towards the Bay of Bengal and provide water to the water scarce Madurai region of Madras Presidency, as the water supply available from the Vaigai River was found to be inadequate to meet the needs of the region [3]. The dam’s purpose was also to divert the waters of the west-flowing Periyar River eastwards, since it caused widespread floods in the Travancore region [4].

According to the 'History of the Periyar Project', a publication compiled by the Public Works Department's Executive Engineer A.T. Mackenzie (published first in 1898 and subsequently in 1963), the idea of diverting the Periyar into Madurai had existed since 1850, when the work on the dam had been started, but was given up later due to fever among workers and demand for excessive wages [1].

The project was revived twelve years later by Major Ryves and  in May 1882, Major J. Pennycuick was entrusted with the responsibility of carrying out the project, who came to be regarded as the architect of the Periyar dam. The dam was made of lime and surki with its total cost estimated at Rs.84.71 lakh. The full reservoir level of the dam is 152 ft with capacity of 10.56 thousand million cubic feet (tmcft) [1]

For the dam, water was diverted from the reservoir by way of a tunnel across the watershed and the Western Ghats to the rain shadow region of the Theni Sivaganga District and Ramanathapuram districts of Tamil Nadu. During the rule of the British in India, a 999-year lease was made, between the Maharajah of Travancore and the Secretary of State for Madras, which provided the British the rights over “all the waters” of the Mullaperiyar and its catchments, for an annual rent of Rs. 40,000. About 60,000 hectares in Theni, Madurai, Sivaganga, Ramanathapuram, and Dindigul districts in present day Tamil Nadu were intended as beneficiaries of irrigation waters from Mullaperiyar [4].

At present, water is brought through a 1.6 km long tunnel till the Tamil Nadu-Kerala border and then flows through open canals to Churuliyar river, which feeds the Vaigai dam in Tamil Nadu. From there a network of canals take the water to the fields. Initially the dam waters were used only for irrigation. Later, the Periyar Power Station in Lower Periyar, Tamil Nadu was built to generate hydro-electricity from the diverted waters. In 1960, a hydel project was also established downriver at Idukky on the assumption that the waters would be available during the monsoons [3]

The Mullaperiyar dam dispute

The dispute between the two States of Travancore and Madras arose in about 40 years following the dam construction over whether Madras was entitled to use the Periyar water for hydropower generation. Initially, Tamil Nadu suffered a setback, but the issue was resolved 30 years later. On May 29, 1970, Tamil Nadu and Kerala signed an agreement, under which Tamil Nadu was allowed to generate electricity from the project and it surrendered fishing rights in the leasehold land in favour of Kerala [1]. Tamil Nadu has been using dam water and land and paying the Kerala government a tax of Rs 2.5 lakhs for the land and electricity generated from the dam. However, the validity of the agreement continues to be disputed by both the states [4].

A number of developments following independence have fuelled this ongoing debate between the Kerala and Tamil Nadu government on the dam reservoir level. There was a drastic increase in population on the downstream of the Idukki river in Kerala followed by microclimatic changes and a decline in the rainfall, which led to decline in the water levels in the Idukki dam. Power generation fell and the diversion to the Mullaperiyar dam was blamed for this decline. Kerala thus argued for reduction in water levels in the dam. The then chief minister of Tamil Nadu agreed to this and when the water level in the dam was brought down in 1980, around 8,000 hectares of Tamil Nadu's rain shadow districts suffered [3].

Tamil Nadu, in recent years, has  made demands  that the storage capacity of the dam be increased from 136 feet (41.5 m) to 142 feet (43 m) to meet the rising demand of water needed for irrigation. However, Kerala has been arguing since 1970 that the existing structure has outlived its safety and longevity and that there is a need to construct a new structure and that it is unsafe to maintain water at 46.3 metres, which is at the full capacity and that it should be restricted to 41.45 metres [4]. Differences on the optimum water levels that the dam can withstand and the concerns of the safety of the dam have thus led to disputes between the two states. The issue has also been complicated by a number of studies that have shown contradictory results.

For example, a study by the Centre for Earth Science Studies in Kerala has found that the dam will not be able to withstand an earthquake of the magnitude of six on the Richter scale at higher water levels if the epicentre of the earthquake is near the dam. Several earthquakes of lesser magnitudes have occurred in the state during the past two decades and scientists have predicted the possibility of earthquakes of magnitude six occurring in the state. The chances of an earthquake occurring in the vicinity of the dam too are high because of the presence of major lineaments and fault zones in the region [3]. The recent recurrence of mild tremors in Idukki district of Kerala have further triggered the debate on the safety of the dam over the last few months [5].

Mullaperiyar damA file photo of the Mullaperiyar Dam

Image Source: The Hindu

Central government studies have however suggested that the water level in the dam can be raised followed by efforts at strengthening the dam. For example, the Central Water Commission (CWC), a premier government agency dealing with dam safety, in 1979 suggested a reduction of water level to 41.45 metres as an emergency measure along with other measures to strengthen the dam. Tamil Nadu agreed to this limit. However, another committee headed by the then CWC chairperson was appointed in 2001 to look into the matter. It stated that the reservoir level be raised to 43.28 metres, after the strengthening measures were implemented. This was to be on an interim basis, and later reservoir levels could go up to the original level of 46.3 metres [3].

A study on the impact of raising of water level in the Mullaperiyar reservoir of the Periyar Tiger Reserve was carried out in 2001. The team included 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). The report had suggested that all kind of wild fauna including wild boar, gaur, sambar, otters, elephants and birds that nest in the reservoir will be adversely affected if the dam height is raised. Kerala had also been arguing against the raising of the dam height in view of this study and the impact that this could have on the environment [3].

In 1998, all Mullaperiyar-related cases were transferred to the Supreme Court. The Supreme court declared in February 2006 that the dispute was not a ‘water dispute’ and that the reservoir level could be raised to 43.28 metres and directed Tamil Nadu to carry out the strengthening measures suggested by CWC, and prevented Kerala from causing any obstruction[4]. However, in March 2006, Kerala’s Legislative Assembly passed the Kerala Irrigation and Water Conservation Amendment Act, 2006. The amendment empowered Kerala’s Dam Safety Authority (KDSA), a body mandated in 2003 by the original Kerala Irrigation and Water Conservation Act to evaluate safety of all dams in the state, which has the power to advise the government to suspend the functioning or to decommission a dam if public safety demanded [4].

Twenty two dams constructed during 1895-1963 including the Mullaperiyar dam were brought under KDSA’s jurisdiction. 41.45 metres was fixed as safe height for Mullaperiyar’s reservoir. Tamil Nadu took the matter back to the Supreme Court and filed a petition on March 31, 2006 to declare the Kerala act as unconstitutional [4]. In July 2009, following the findings of a recent study by IIT, Roorkee, which had discovered that the dam would collapse if  at any time an earthquake measuring 6.5 on the Richter scale happened and that  nearly forty lakh people who were fearfully anticipating this  have  to be reassured by allowing the new dam to be built, the Kerala  government proposed that a new dam could be built 1,300 feet downstream of the present Mullaperiyar reservoir, so that the safety of  the people  of Kerala could be assured  from the existing high-risk structure, which could fail at  any time, endangering lives [6, 7, 8, 9, 10, 11, 12].

However, Tamil Nadu once again rejected the idea of constructing the new dam over the Periyar River even though the proposal had been cleared for approval by the Centre in 1979. In February 2010, the Chief Minister of Kerala applauded the Supreme Court ruling demanding a review of the safety aspect of the Mullaperiyar. The apex court appointed a senior committee to study the safety of the dam, discuss increasing its water level above 136 feet and evaluate Kerala’s demand for a new dam. The Supreme Court appointed former chief justice of India A.S. Anand as the chairperson of a techno-legal panel formed to examine the strength and capacity of the more than a century old Mullaperiyar dam in Kerala [4].

In March 2010, Tamil Nadu Chief Minister M. Karunanidhi  said that Tamil Nadu would never give up its rights over the Mullaperiyar dam since that would  create problems for farmers in that  area. However, people in Kerala argue that the 1886 deed should not be continued since it was forced upon the Travancore ruler [4]. People in Tamil Nadu argue that Kerala is eyeing extra water from the Mullaperiyar reservoir to generate electricity. Power generation at the Idukki reservoir, downstream of the Mullaperiyar dam will come to a halt if the reservoir level is increased from 41.45 metres to 46.3 metres. The Kerala government, however, maintains that the Idukki project was designed after discounting the 46.3 metres water storage in the Mullaperiyar dam [4].

Farmers in Tamil Nadu maintain that water rights have already been established during the past century and cannot be reverted. The Kerala government, however, argues that the gross area irrigated by the Mullaperiyar reservoir actually increased from 24,280 ha in 1896 to 69,200 ha in 1970-71 (when the water level was 46.3 metres) to 92,670 ha in 1994-95 (when water level was reduced to 41.45 metres). But Tamil Nadu claims that this is due to the modernisation of Periyar-Vaigai project, which reduced seepage losses by 6.7 thousand million cubic feet [4].

The current status of the dispute

In February 2010, following the Court's directions, the Union government thus constituted an empowered committee, headed by former Chief Justice of India A.S. Anand, to hear the parties on all issues that would be raised before them and furnish a report to the Court. The committee's tenure has been extended up to February 2012 [13]. According to recent reports, Anand Committte is set to examine expert's reports on dam safety amidst reports of the increasing threat to the dam structure due to increasing water levels because of incessant rains [14] and predictions that an earthquake can cause damage to the dam and threaten the lives of 3.5 million people, the issue has been recognised as a national problem needing urgent attention. According to recent reports, the centre has invited Tamil Nadu and Kerala for talks on the dam. This will be the first official meeting between the two states on the issue in the last six years [15].

The debate in its present form raises a number of dilemmas that complicate the matter even further. For example, raising the level of water in the dam can pose a serious danger to the lives of the people living downstream. At the same time, experts believe that the construction of a new dam besides creating a heavy financial burden, would pose as a threat to the Periyar Tiger Reserve causing tremendous environmental damage and would be subject to the same problem of seismicity. At the same time, the irrigation needs of the farmers in Tamil Nadu are equally important and relevant.

As the political debate for and against the safety and usefulness of the dam continues within the states of Tamil Nadu and Kerala,  people in Idukki area and environmental and water activists have expressed their concerns about the safety of the dam and argue that this is an issue of nation wide importance [17]. Experts warn that more than 500 dams in India are too old and have been constructed during the British times [17] and some 115 of them, are more than a century old and capable of unleashing potential devastation if breached. All of these dams are still very much in use with the the oldest being the Thonnur Tank (24.38 metres high), located in Karnataka and dating back to 1000 AD [19].

Experts such as Menon Sreelatha (2011) argue that, inspite of evidence in the form of some studies that have warned against the safety of some of these dams, no proactive efforts are being undertaken to decide about their future and decommission some of them or devise disaster management strategies [19]. India still does not have a clearly defined, legally binding accountability mechanism in case of dam failures [17]. The Dam Safety Bill (2010) [21], which was introduced in the Lok Sabha in August 2010, is yet to be discussed [17]

Mullaperiyar damThe Mullaperiyar dam

Image Source: Wikimedia Commons

Water activists such as Himanshu Thakkar, coordinator of the South Asia Network on Dams, Rivers & People (SANDRP) are highly critical of the stance taken by Central Water Commission (CWC) and the Water Resource Ministry and argue that safety of the people should be given top priority and that the state of Kerala should be given every right to take the decision about the decommissioning of the dam [18] and that the Mullaperiyar dam needs to be decommissioned urgently to protect people in the downstream area of Idukki [20].

In a recent issue of the Economic and Political Weekly, Experts For Forum for Policy Dialogue on Water Conflicts in India [16] have made some important suggestions/recommendations to resolve the deadlock that include:

  • Reconfirming Kerala’s commitment to provide the present amount of water to Tamil Nadu
  • Redefinition of the role of the Mullaperiyar dam as a diversion dam rather than a storage dam and creation of necessary the storage capacity needed for Tamil Nadu inside the state with adequate assistance from the centre
  • Undertaking studies on:
    • The storage capacity needed for Tamil Nadu
    • Redesigning of the diversion and conveyance system and minimising storage in the dam as close as possible to the minimum regulatory storage required on the basis of this redesign
    • Measures to strengthen the dam at the new level
    • Undertake hydrological studies on flow at the dam site and a schedule for the regulatory storage
    • To work out arrangements in the transition phase
  • Establish a tripartite board consisting of representatives of the Government of Kerala, Government of Tamil Nadu and the Union government to oversees the preparation of a reservoir operation plan and monitor and modify it throughout the year [16].

Against this backdrop of strong voices from the local population, environmental and water activists and experts that argue for the need to consider safety issues as priority while evaluating old dams such as the Mullaperiyar, the outcome of the official meeting at the Centre between the two states on the dam currently remains awaited.

(The author is a public health researcher based in Trivandrum, and also works with the India Water Portal)


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Image Courtesy: The HinduWikimedia Commons