The 115-year-old Mullaperiyar dam is in the news again. The contention is regarding the safety of the dam, the insecurity amongst the downstream population in Kerala, and the water needs of a large section of people from the Vaigai basin. The tension between Tamil Nadu and Kerala on this issue has escalated recently, with the political class in both States resorting to agitation. There have been reports of occasional violence and disruption of movement of vegetables and some other essential commodities from Tamil Nadu to Kerala. Both parties have approached the Prime Minister of India to intervene in the situation.

For various reasons, the 1886 agreement (lease deed) between the then Maharaja of Travancore and the erstwhile Madras Presidency, perhaps the first formal inter-state, inter-basin water sharing and transfer in India, which led to the construction of the Mullaperiyar dam — now 115 years old — has come under stress in recent times. The end result has been the escalating tension between Tamil Nadu and Kerala, and as each tries to prove the validity of its case, the possibility of finding an amicable settlement of the issue seems to recede further every year. The situation is further compounded by the recent tremors around the dam, apparently causing fresh fissures in the structure.

POLARISED POSITIONS

One of the polarised positions, taken by the Tamil Nadu government, insists that the Mullaperiyar dam is safe, and that the water level must be maintained at the maximum level of 142 feet, as per the agreement. The other position, taken by the Kerala government insists that a new dam downstream of the present dam must be built to fulfil requirement to the Tamil Nadu government because the present dam is unsafe.

We need to think beyond the present polarised positions, because both the positions are seriously flawed. The Mullaperiyar dam is now 115 years old, and to the common eye shows all signs of the ravages of time during this long period. While it is true that a Central Water Commission (CWC) team has stated that the dam would be safe, provided certain specified repairs are carried out, expert opinion on this is divided and there are eminent experts who believe that the dam has not been demonstrated to be safe on account of hydrology studies, as well as on the account of the technology and material used for the dam during its construction. It is also not clear if all the repairs recommended by the CWC have been effectively carried out.

There are increasing reports regarding obvious damage to the dam. And recently, there have been a series of tremors in what is anyway a seismically-active zone with epicentres close to the dam. While most experts would agree that the dam may be considered relatively safe for lower heights of storage, opinion is divided on maintaining water levels at the maximum height, specified as 142 feet.

Similarly, there are difficulties with the new dam downstream. The new dam is being planned approximately 400 metres downstream of the present one, with a larger storage capacity. Firstly, this would submerge a substantial additional portion of the Periyar Tiger Reserve. Also, it would mean an additional massive structure right inside the Periyar Tiger Reserve, and a continued massive interference during the years it would take for the dam to be built. The dam would be subject to the problem of seismicity. It would create a heavy financial burden, along with associated issues of cost sharing. It would cause additional environmental damage in Kerala to fulfil Tamil Nadu's requirements.

IMMEDIATE ACTION

As a short-term, immediate measure, water level needs to be brought down to around 120 feet or less. Given the fact that expert opinion on dam safety at higher water levels is divided, given the increasing seismic activity in the area, given the high levels of insecurity felt by downstream residents, and given the fact that the ravages of time on the dam are increasingly evident to the common eye, it would be best to use the precautionary principle and keep water level low. A 120-ft level has generally been acceptable to the Kerala government as well.

Water can be comfortably delivered to Tamil Nadu at the 120-ft level, and Tamil Nadu should be encouraged to divert as much water as it can and store it inside Tamil Nadu in balancing reservoirs or other storages.

LONG-TERM ACTION

Both the states also need to step out of political jingoism and short-sightedness on the issues and think of a long-term strategy. First, come to a common understanding of the role of the Mullaperiyar dam as a diversion dam rather than a storage dam. This will imply that the water level to be maintained in the dam will be governed by the ability to deliver water to Tamil Nadu efficiently, rather than on maximal water storage behind the dam. The storage capacity needed for Tamil Nadu should be created inside Tamil Nadu, with adequate assistance from the Centre, rather than at the cost of greater environmental damage in Kerala through a new dam.

Second, reconfirm Kerala's commitment to provide the present quantum of water. The Kerala government, in any case, has publicly already confirmed this commitment.

Third, immediately undertake studies on a) the requisite capacity needed inside Tamil Nadu, b) the redesign of the diversion system (connect it to the storage sites and possibly increasing the size of the channels to accommodate greater flow) to minimise storage behind the dam, which should be reduced to the minimum regulatory storage required, c) measures to strengthen the dam at the new level, d) a hydrological study of flow at the dam site and a schedule for the regulatory storage and e) working out arrangements in the transition phase.

And finally, though the dam would continue to be in the control of Tamil Nadu and operated by it, there should be a tri-party board consisting of representatives of the Government of Kerala, Government of Tamil Nadu and the Union Government — along the lines of the Tungabhadra Board — that oversees the preparation of a reservoir operation plan and monitors and modifies it throughout the year.

The measures that have been outlined above are based on what we think is the minimum that would be able to resolve the conflict. There are many ways in which these can be improved upon. For example, every dam has a life, and it may be necessary to think through a strategy of minimising the requirements through local water harvesting and increase of on-field and irrigation efficiency, so as to gradually reduce the requirement from the dam, so that eventually the dam may be decommissioned.

In fact, there is a need to shift to ecosystem-based river basin planning with limited quantities of exogenous water coming from Mullaperiyar only, to strengthen and supplement the local water regimes in the Vaigai basin. However, that is for future consideration.

(The authors are part of the Forum for Policy Dialogue on Water Conflicts in India.)

Related Topics