Tag Archives: dam safety

It will be a folly to build new dam at Mullaperiyar

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The proposal for a new dam at Mullaperiyar is not in the best interests of Kerala. It should press for phased decommissioning the dam while ensuring water supply to Tamil Nadu, at least for a few decades in reduced quantities.

A new dam means handing over the problems to another generation, about 50 to 100 years from now. This is also what the Maharaja of Travancore did by leasing land for 999 years. But that was because his hands were forced. Kerala has to see that this would not happen again.

Feasibility of new dam
Mullaperiyar dam site is in a seismically active area. Even though technologies are now available to build earthquake-resistant dams, it is still advisable not to build dams near fault lines. The area also falls in the Periyar Tiger Reserve and National Park. Various clearances including forest clearance will be required to build a dam there. An environmental impact assessment will have to be done and this is not going to be very favourable. The Gadgil Committee on Western Ghats has already called for decommissioning of old dams on the Ghats. Construction of new large dams on the Ghats is no more considered an environmentally sound proposition.

There are actually few locations along the course of the river for building a new dam. The one proposed is downstream of the present dam on land not leased to Tamil Nadu. Kerala is already saying that it would build new dam on its own and will not be willing to lease additional land to Tamil Nadu. Tamil Nadu will object to its losing ownership and control over the dam. Use of this land will require denotificaton of the sanctuary area required for expanding the reservoir. This, in turn, necessitates a resolution by the Legislature and approval by the Centre.

New technologies will be needed if Tamil Nadu proposes to build a dam upstream of the present one and even that will require negotiation of a new agreement between Tamil Nadu and Kerala and environmental clearances. There will be specific objections to building dams that will store water above the current full reservoir level which is fixed at 142 feet by the Supreme Court. The negotiations between Kerala and Tamil Nadu can prolong for any number of years, given their history of reviewing the Parambikulam-Aliyar Project agreement.

The construction activity, once started, is going to cause serious disturbance to wildlife in the area. This will hinder environmental clearances and invite protests. Issues like lower riparian rights of Kerala too have to be considered while proposing a new dam. (Lower riparian rights are internationally recognised. They, among other things, specify that a certain amount of water should be allowed to flow down while damming a river.)The adequacy of spillways of Idukki dam to handle additional flow too will have to be considered, especially in view of the recent change in weather patterns.

In fact, there is hardly any justification for building a new dam in national park on the Western Ghats. Full scale inter-basin diversion of river waters is not permissible even in other areas these days.

Kerala’s incapacity to build dam
Though Kerala says it can build the dam, the work would have to be entrusted to an outside party, probably to a multi-national consultancy and dam-builders. The State Water Resources did not have the capability to build such a dam in a time bound manner. Two its last projects, Edamalayar and Kallada were plagued by cost and time over-runs and corruption. The State Electricity Board too doesn’t have experienced engineers for this work, though it once had the capability. (The Board neglected its civil wing and engineers who have designed and executed large dams have all retired). The State Public Works Department is recently in the lime light for faulty construction of buildings and bridges and corruption.

Though a former Water Resources Minister had boasted that the dam could be completed in a year, nothing like that is ever going to happen in that Department. We have engineers who always stated that the Mullaperiyar dam is unsafe but could not prove before the Supreme Court that a 120-year-old dam posed sufficient risk to attract the precautionary principle! (So, the government thought that a retired jurist, who incidentally believed that the dam would be safe for another 100 years, was a better option to represent Kerala in the Committee set up by the Supreme Court.)

Phased decommissioning
Given this scenario, the best option is to press for phased decommissioning of the old dam. Tamil Nadu has not so far accepted Kerala’s long standing demand for new dam. So, it is time that Kerala focus on the demand for decommissioning of the dam and not fall into the trap of building a new dam.
Former Union Secretary for Water Resources Ramaswamy R. Iyer has said that it will be a folly to build a new dam on Mullaperiyar. “We can start thinking of phasing it out. That means giving people time to get adjusted to this idea and seek alternative sources of economic activity, and perhaps a different pattern of development that does not require so much water,” Mr. Iyer said in an interview to Frontline magazine published in December 2011.
“Accept the fact that the dam is not going to be permanent. Explore alternative means of supporting the livelihoods of people who will be affected by the phasing out of the dam,” Mr. Iyer said.
The phased decommissioning of the dam, which he suggests, will not be without problems. Currently, there is no means to lower the reservoir level of Mullaperiyar dam beyond 136 feet other than drawing of water through tunnels by Tamil Nadu. This is because the saddle spillways are at 136 feet. The capacity of tunnels is limited to 2200 cusecs and will be inadequate to manage flows caused by floods which will exceed the capacity of tunnels.
There is a proposal that Tamil Nadu should build a new intake tunnel at the level of 50 feet from the base. (The present intake is at 104 feet and water below this level could not be drawn). The techno-economic feasibility of this proposal has been questioned by some engineers. But new technology may help, though it may be costly. The Mullaperiyar dam does not have a sluice gate at the bottom for emergency discharge of water. There was a proposal for a tunnel to downstream of Mullperiyar River for discharge of water, but it has not come up for serious consideration despite the risks posed by the dam.
It is often convenient for Kerala politicians to call for new dam. But the proposal does not suit current thinking on environment and river management. Building a new dam will be a folly as pointed out by Mr. Iyer. Instead of undertaking such a foolish proposal, Kerala should demand a time table for phased decommissioning of the old dam.

Related link: A dam has a life— Frontline report, December 2011.

Mullaperiyar- fresh litigation will be ill-advised at this stage

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Kerala Government plans to approach the Supreme Court yet again on the Mullaperiyar issue— this time over the alleged failures of the supervisory committee appointed by the Court to properly manage release of water from Dam through the spillways.

This is just an attempt by the politicians to buy time and hoodwink the public. The supervisory committee has representatives of Kerala and Tamil Nadu and Central Water Commission. The question of failure to issue timely warning before release of water through the spillways is a matter that the State government should be able to settle administratively, if necessary seeking intervention of the Centre. It will not be appropriate to agitate the Supreme Court now.

Moreover, it is not Kerala’s case that the Tamil Nadu did not warn it of impending release of water. There were reports that Theni Collector did so a few days ago. The complaint is that the Idukki Collector was not informed six hours before the release. Tamil Nadu apparently wanted to record that the water level touched 142 feet. When water level reached 141.9, it became imperative for Tamil Nadu to release water immediately as the inflow was very heavy. There needs to be an understanding on gradual release of water without waiting for the water level to touch 142 feet.

Kerala should also insist upon its lower riparian rights. The Expert Committee appointed by the Supreme Court had mooted construction of a tunnel to drain water into Periyar River downstream. This is also important from the point of view of safety. All modern dams have Bottom outlet tunnel which will facilitate emptying of the dam in case of an emergency—the Mullaperiyar dam does not have one, being one designed in the 19th century.

Every time Kerala has gone to Court over the Mullaperiyar issue, it has led to closure of its options. It has already lost its case that Tamil Nadu should raise the water level of Mullaperiyar beyond 136 feet only after exhausting storage at Vaigai Dam and that the spillway shutters should be opened gradually. In fact, when Kerala is arguing that the dam is not safe, it should be prepared for sudden release of water. This was what was lacking downstream of Mullaperiyar this Monday.

Kerala has failed to set up monitoring facilities it proposed on earlier occasions downstream of the Dam. Around 50 monitoring installations on the dam and reservoir, under control of Tamil Nadu, are reportedly not functioning. This is an issue that Kerala should be taking up legally or administratively. Even a modern dam without functioning monitoring equipment is unsafe.

Kerala had rushed to nullify a Supreme Court order of 2006 though legislation within weeks of the Court issuing the order. The legislature in its wisdom fixed the water level at 136 feet without building up supporting material. The Kerala Dam Safety Authority, which is a quasi judicial body, on the other had could have commissioned international studies on Mullaperiyar under the law and fixed the water level appropriately which would have been difficult to question before the Supreme Court.

When the Court quashed the law, Kerala suffered a multiple blow. Its arguments had led to the Supreme Court appointing a supervisory committee. As the supervisory committee of the Supreme Court is now managing the water level, it could put blame on Tamil Nadu only if it disregarded directives of the committee. Kerala will not even be able claim damages from Tamil Nadu for any losses caused by release of water or dam failure.

Kerala had ample time to prepare internationally acceptable documents on safety of Mullaperyar Dam from 2006 and even before. But it always rushed to do studies at the last minute. When safety of the people was paramount, one of the first studies it commissioned over a short span of time after 2006 was on submergence of forests and wildlife. (An analysis of errors in that study is available here. The author had to admit before Court that he had done a copycat job of work done by a State agency.)

Though there was an erroneous observation in the 2006 judgment (See Mullaperiyar- behind the veil.) that waters from Mullaperiyar would be contained in Idukki reservoir in case of failure of the former, Kerala failed to complete and produce the Dam Break Analysis before the Supreme Court in the case filed by Tamil Nadu challenging Kerala’s dam safety law.

 

Extract from judgment
Extract from the judgment of Supreme Court in ORIGINAL SUIT NO. 3 OF 2006 between Tamil Nadu and Kerala

Though the State Information Commission has ruled that this and other studies are public documents, the Principal Secretary of Water Resources Department has issued an illegal order against release of documents pertaining to the Mullaperiyar Dam as long as the issue is under litigation. Perhaps this is one reason why it wants another litigation.

As its strategies have failed so far, it is high time that it reconstituted the Mullaperiyar Special Cell with fresh talent and drew up fresh strategies.

For further reading:

Mullaperiyar: Kerala seeks review of Probable Maximum Flood

 

 

 

 

Moving NGT on Mullaperiyar can boomerang on Kerala

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Kerala’s move to approach the National Green Tribunal against raising of the water level in Mullaperiyar dam is likely to boomerang on Kerala.

Environmental arguments similar to those against raising of reservoir level can be raised against lowering the reservoir level also.

In fact, changes to the ecosystem created by the dam and its water will be more pronounced while lowering the water level.

Kerala’s argument is that the raising of water level in the reservoir submerged nearly four decades old vegetation just above 136 feet level in Periyar Tiger Reserve. Lush vegetation including some specialised species have grown in the local environment created by lowering of the water level.

Now, let us look at what will happen if water level is reduced to 132 feet as demanded by Kerala at one point of time, or eventual phased decommissioning of dam. Lowering of the water level will result in the water table going down in many parts of Periyar Tiger Reserve. This would cause a relative drought conditions in many parts of the Sanctuary compared to the present situation and will loss of biodiversity and density of vegetation. The specialised species will not survive in its original location.

Legal position:
Environmental impact argument is something rejected by the Supreme Court in its 2006 verdict itself. However, Kerala tried to raise it again when Tamil Nadu challenged Kerala’s dam safety legislation before Supreme Court. For doing this, it commissioned a scientist from West Bengal, who produced a study report within a matter of weeks. The report had several errors and it was essentially a reproduction of arguments made by KFRI over which Kerala had argued its case earlier. Though these mistakes had been pointed out, Kerala went ahead with producing the author as a witness before the Court. During cross-examination, he admitted he had copied from the KFRI report. This meant that Kerala had no new argument or point to be presented before the Court. Now, Kerala is trying to revive its lost cause by approaching NGT.  It is not even considering the fact that Supreme Court is above NGT.

In any case it will be a win-win situation for TN. If the NGT rejects Kerala’s prayer, TN will have another handle. If it upholds Kerala’s argument, TN can use it in future against lowering of the water level or decommissioning of the dam.

Kerala’s argument goes against what the State itself is proposing to do. The new dam it is proposing to build at Mullaperiyar will submerge some areas of Periyar Tiger Reserve. It is also seeking Central clearance for raising the height of Peppera dam near Thiruvananthapuram by at least three metres submerging about 80 acres of forest. Though the area submerged by increased water level in Mullaperiyar dam is larger than these, the forests that would be submerged by the new Mullaperiyar dam or augmentation of Peppara dam are part of ecosystems that are hundreds of years old. Obviously, much more value is to be attached to the latter.

Moreover, Kerala has done the same thing that TN is doing. Water level at Idukki reservoir had remained low for about three decades. Kerala carried out augmentation scheme under Idukki project to improve inflow. None batted an eyelid, when vegetation that grew over the period was submerged by increasing water level. Besides, the area being submerged at Mullaperiyar was leased to TN much before the enactment of environmental laws.

If we really care for environment (instead just using environmental arguments with the wrong belief that it will win a case in which the key issue is safety), we should demand environmental flows downstream of Mullaperiyar dam, abandon the proposal for new dam and seek phased decommissioning of the old dam.

Mullaperiyar studies are public documents

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The Kerala State Information Commission has ordered Kerala Irrigation Department to release study reports and documents, submitted by it before the Supreme Court in the Mullaperiyar case filed by Tamil Nadu, under Right to Information Act. (See earlier post here)

The Department had refused to provide reports including the Dam Break Analysis on the ground that they were documents of “Strategic interests of the State” which were not required to be released under the RTI Act. The Commission did not uphold this contention and points raised by the Department in very detailed 70-page affidavit.

The complaint against the Department’s stand was made to the Commission as back as  in March 2012. The hearing was taken up only by the middle of 2013 and was completed by September 2013. However, the Commission took nearly six months to issue the order.

RTI

Order of State Information Commission

Earlier posts:

Mullaperiyar: behind the veil
Mullaperiyar dam break analysis: area of submergence
Mullaperiyar: strategic failure of Kerala government
K. T. Thomas and Mullaperiyar
Mullaperiyar: Directive against disclosure of dam break analysis
Mullaperiyar and Kerala’s technical studies
Conclusions of empowered committee of SC in Mullaperiyar case

K. T. Thomas and Mullaperiyar

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Member of the empowered committee of the Supreme Court on Mullaperiyar K. T. Thomas has stated in an interview to Malayala Manorama that the Mullaperiyar dam will stand for another 100 years.  This should surprise many.

Mullaperiyar dam

Mullaperiyar dam

According to experts, the normal life of a well-built concrete dam is about 60 years. None could predict the life span of a composite dam like Mullaperiyar with accuracy. However, there is enough evidence about the weakness of the old structure which actually stands supported by the concrete backup built by Tamil Nadu as part of strengthening measures. The Central Water Commission itself had acknowledged the weakness of the old structure in 1979, and if the backup would support the waters, its life span is only less than 60 years. (The strengthening measures were proposed for keeping the dam in service for 30 years at water levels higher than 136 feet.) Studies by the IIT, Roorkee and IIT Delhi showed that the composite structure could not stand a once in a 100-year flood or earthquake of the magnitude of 6.5 on the Richter scale.  Mr. Thomas ignored these findings.

In his report, Mr. Thomas says that the capacity of the Idukki reservoir is 75 tmc and water level in the reservoir had never exceeded 54 tmc. Both these averments are wrong. The capacity of the Idukki reservoir is 70.5 tmc at full reservoir level. It can reach 74.4 tmc at maximum water level. However, water would have to be regulated once it reaches full reservoir level.

The water level in the reservoir had exceeded 70.5 tmc twice and the spillways had been opened. On several occasions, it had crossed 54 tmc. Then, why did Mr. Thomas quote these figures. Is it to substantiate the argument that waters from the Mullaperiyar (11 tmc) would be contained in Idukki reservoir, in case of a failure?

The argument that the former judge actually raises is that the Mullaperiyar reservoir level should be kept at 136 feet so that Idukki could get waters for power generation. This had never been the argument of Kerala and it had never got even five per cent of the water from Mullaperiyar.  (It is also notable that the former judge has suggested that an intake tunnel should be constructed at 50 feet from the base of the dam.  Even without such a tunnel Tamil Nadu is drawing almost all the waters from the dam. With such a tunnel, it will not have to spare any waters for Kerala.)

Kerala wanted the level to be kept at 136 feet for safety reasons. However, the argument that the dam is unsafe had been rejected by the Committee. So, it may be better for Kerala to change the demand for new dam as neither the Centre nor Tamil Nadu are going to agree to that given the findings of the Committee.

So, it should call for phased decommissioning of the dam on the basis of continuous evaluation of the condition of the dam by a competent body like the Dam Safety Commission. (A tunnel at a lower level as proposed by Mr. Thomas could aid this by allowing Tamil Nadu to draw water at current levels for years).  Kerala should also press for its lower riparian rights and a good share of its own waters which had been denied to it through an agreement between a weak princely State and a colonial power.