The majority is for a new dam; there is also a call for lowering of the intake tunnel

Differences have intensified among the supporters of Mullaperiyar Action Council over whether a new dam and new agreement with Tamil Nadu on Mullaperiyar or lowering of the intake tunnel from the existing Mullaperiyar reservoir would be the best option for Kerala.

Politicians and officials are unanimous that a new dam is the best option to ensure the safety of people living downstream the existing dam and secure the interests of the State. Kerala has presented this view before the empowered committee of the Supreme Court and the Central government with the assurance that the quantum of water for Tamil Nadu will not be reduced.

No returns here

Some members of the legislature committees have even mooted the idea that Kerala should build the new dam as a protective structure if Tamil Nadu does not come to the negotiating table for a new agreement. This will mean that Kerala will have to fund the new dam without any returns from the investment. There will also be no new agreement to replace the one that was forced upon Travancore by the British. (According to records, the Travancore Maharaja had resisted the proposal for years.)

Scene abroad

The proposal for a new dam in any form will have the disadvantage that it does not address the environmental concerns. The thinking about dams is changing and no environmentalist these days support inter-basin diversion of water as had been done in the case of Mullaperiyar 116 years ago. Many dams are being decommissioned in countries such as the United States of America and never rebuilt. The objective of decommissioning is often the eco-restoration of natural river systems.

The construction of Mullaperiyar dam had led to felling of large areas of forests directly by the British and indirectly through starving of forests downstream of water. The dam allowed not a drop of water to flow down except under maximum flood conditions. Current international law is against agreements that deny lower riparian rights.

Kerala's proposal for new dam is essentially aimed at resolving safety concerns at least for another 50 years and does not address issues such as Kerala's rights over the waters, though it does cater to Tamil Nadu's need for water.

Safety of new dam

The proposal allows just about five per cent summer flows down the river while guaranteeing water to Tamil Nadu at current levels. It also ignores the question whether a new dam is advisable in Idukki district which is experiencing frequent tremors, especially when some of the tremors are suspected to be reservoir induced.

The environmental impact study for the new dam is yet to be done and it is not clear whether the Central government would give the necessary clearances. In any case, it will be long process.

A lengthy process

The construction of the new dam also is likely to take years, though the government is considering technologies that would help it to construct the dam within a short period. Almost all dam projects taken up by the State had faced delays and cost escalation in the past. Hence, the proposal for new dam does not address immediate concerns about dam safety. Moreover, a new agreement between Tamil Nadu and Kerala, fair to both the States, is not in sight as Tamil Nadu is not even willing to come to the negotiating table.

The other view

The alternative being proposed (by C.P. Roy of the Action Council who has since been ousted as its chairman over differences on the issue) is the lowering of the level of the intake to 50 feet so that Tamil Nadu could draw water which otherwise remains as dead storage. (The current level of intake tunnel is at 104 feet.) This would involve construction of a new tunnel, the technical feasibility of which is yet to be established. If feasible, this will help lowering of the reservoir level from 136 feet to about 100 feet and allow Tamil Nadu to draw water at current levels for an indefinite period. Kerala will get waters released to maintain lower water level. Tamil Nadu will be compensated for this by release of the dead storage.

Tamil Nadu may have to construct the tunnel under this proposal and may have certain advantages from the proposal. It will retain control of the dam and a new agreement may not have to be signed.

Limited damage

While construction of new dam will involve considerable disturbance to the Periyar Tiger Reserve, the disturbance to wildlife from the new proposal would be limited that from construction of the underground tunnel from the Tamil Nadu side. The land area under the Tiger Reserve will go up with lowering of the water level.

T. Shivaji Rao, Director, Centre for Environmental Studies, GITAM University, Visakhapatnam, suggested on Monday that investigations might be carried out to find if adequate water could be supplied to Tamil Nadu either by pumping or by using siphon spillways or other suitable works from full reservoir level of 120 feet. He also suggested in a press statement that cloud seeding, as practised by China, should be used to maintain water levels and overflows and ensure adequate water for Tamil Nadu and Kerala.