The Mullaiperiyar Dam [Image (C) The Hindu]
The Mullaiperiyar Dam [Image (C) The Hindu]
The Mullaiperiyar dispute : Arguments and Counter arguments (Part 3)
This article originally appeared in CRI content has now been subsumed in The views expressed here are personal and do not necessarily reflect those of the editors of

We had earlier discussed inter-state relations between Kerala and Tamil  Nadu, particularly those concerning water disputes as precursor to studying the Mullaiperiyar dam dispite. Later, we looked at the genesis of the Mullaiperiyar conflict and also its evolution over the last 20-30 years.  You may read the earlier posts here: [Part 1, Part 2]

In this post we proceed to examine some of the myths, charges and counter-charges that have been made by both the sides with regard to the Mullaiperiyar dam dispute.  The responses are gathered from the counter-arguments made by the states and should be seen as such. To begin with lets us deal with some of the most common themes of discussion:

Old lease agreement for 999 years is simply unjust and was signed in colonial times. Hence such an agreement needs to go and a fresh one is needed.

The agreement has been upheld by SC. Further it was also renewed by the two states in 1970. Tamil Nadu further points that only reason why it renounced its claims to  Peermede and Devikulam taluks (in which the dam lies today) in favour of  Kerala despite these taluks populated by a vast majority of Tamil was because of gentleman’s understanding on Tamil Nadus right to own, maintain and operate the dam across Mullaiperiyar.

Old lease agreement is unjust with regards to monetary compensation to Kerala.

These areas were completely inaccessible (from Travancore side) and under-developed. The dam construction itself was carried out under extreme duress and hence the monetary compensation in 1886 was justified.

In 1970, while monetary compensation was suitably increased, Tamil Nadu had also surrendered rights over fishing, tourism, and security of dam. This contributes major significant revenue to Kerala.  Hence it is wrong to state monetary compensation is little.

Many have even suggested increased monetary compensation and even transfer of equivalent power to Kerala as produced in lower camp.

Dam is 116 yrs old masonry dam and that its initial life was 50 yrs.

Life of a dam is subjective to its maintenance and strengthening over the course of time. Chigali dam, Karnataka is an example of new dam collapse. There are numerous dams in Europe and USA that are over 100 and even 300-400 years. Kallanai reservoir itself stands the test of time. Newer dams have failed due to improper maintenance. Please see this for more information.

Old dams cannot be strengthened and have to be decommissioned.

As pointed above it is far from truth.

The Roosevelt dam in the US state of Arizona is a shining example. The Roosvelt dam is the world’s highest masonry dam, conceived in 1889, approved in 1903, was started in 1906 and completed in 1911. It is 289 feet high and 723 feet in length. In the 1960’s this dam was even made a National historic landmark.

In 1980’s under dam safety projects, modifications were designed so that it met safety standards and flood control affairs. This was carried out after engineers determined issues with safe release under maximum flood and maximum credible earthquake occurrence near dam.  Problems included weak mortar joints, cracks and faults in the underlying bedrock, and numerous old tunnels that had to be plugged in its foundation.

The dam was resurfaced with concrete.  Modifications to Roosevelt Dam now allow drainage to the dam’s foundation to protect against earthquake failure, along with added low-level outlet capacity. The dam now has a structural height of 357 feet and a crest length of 1,210 feet. Hence we can see in the case of Roosevelt dam, which it was of similar age masonry dam that too rubble, faced similar problems, and has now been strengthened for earthquake and even has huge expanded capacity.

Joux dam , a French masonry structure of slender profile dating from 1905, has been heightened in 1952 by a top concrete section and post-tension anchors . Rockfill buttressing was used in 1983 to replace the post-tension anchors that were weakened by corrosion.

Upper Glendevon gravity dam in U.K. has been provided with a rockfill buttress on its downstream face to improve its seismic stability that was considered inadequate specially in the presence of leaking vertical monolith joints and horizontal construction joints leading to significant uplift pressures

Safety – Strengthening works carried out in MP dam:

The safety work carried out in case of Mullaperiyar is almost similar. In the old dam front and back of the dam are constructed as a Lime based Stone structure. The centre of dam was filled with concrete and mortar.  Gravity dam withstands the pressure of water and tremors using its weight. Gravity dams are among the safest dam designs and in India almost all dams are of this type. Idukki dam is in fact the one and only arch dam!

As a short term action, to increase the weight of dam, 21 feet wide, 3 feet thick RCC capping structure was created on top of the dam for its entire length. Due to this, the weight of the dam is increased by 35 tonne per metre, i.e. totally 12000 tonne weight has been added to the structure.

Pre tension anchoring

As a part of medium term action, cable anchoring was done on the basis of Pre-stressing technology. At a distance of 5 feet away from front of dam on top surface, 4 inch diameter holes were drilled throughout the structure up to a distance of 30 feet inside earth.

Inside these holes, 34 numbers of 7 mm thick high strength wires were stranded together and inserted. To support these cables on foundation rocks, initially concrete was poured to a depth of 20 feet and then cables were inserted from top at a force of 120 tonnes. In this stage, concrete mix is poured again to fill the hole and then it is closed at the top. Due to this, these pre-stressed cables hold the dam strongly with foundation rocks with a force of 120 tonnes. 95 such cables were inserted and concrete filled at a distance of 9 feet for the entire length of the dam and strengthened to withstand tremors.

As a long term measure a 32 feet wide RCC structure with 10 feet deep foundation up to a height of 145 feet above ground enclosing the cap structure was erected on the back of the dam. Existing dam and new structure were designed and joined together using state-of-the art technology to behave as a single dam structure.

Based on CWC’s recommendation, whilst building the strengthened structure, two drainage galleries were built at a height of 10 feet and 45 feet in new structure. Based on this, water leakage from dam is being calculated daily. It has been proved and established scientifically that certain amount of water must leak from the dam if it needs to be safe, strong and healthy.

All dams have some seepage as the impounded water seeks paths of least resistance through the dam and its foundation. Seepage must, however, be controlled in both velocity and quantity. Thus its monitoring seepage is necessary tool to know safety of dam. Drainage channels are provided for controlling this. This link gives you a better idea.

When water level rises above 152 feet, to safeguard dam excess water is evacuated by a structure with 10 sluices, each measuring 36×16 ft already installed. Using this 86,000 cu. ft of water/second can be evacuated.

Moreover, based on the advice of CWC, an extra evacuation capacity of 36,000 cu ft/second was added by constructing 3 sluices measuring 40×16 ft. So the current evacuation capacity of the dam is 1,22,000 cu ft/second.

This dam also has an associated baby dam.  Water enters near Baby dam only when the water level near main dam exceeds 112 ft. This also means when the water level of the main dam is 152 ft, baby dam has only 40 ft of water pressure. But still, it was decided to strengthen the backside of baby dam using RCC backing and works were started.

This was not completed due to lack of cooperation and SC has in 2006 ordered its completion and cooperation to be extended. Periyar dam has also been strengthened by buttressing as per CWC.

Tamil Nadu’s argument is that through means like those mentioned above old dams can be strengthened and even capacity extended.  Tamil Nadu side brings out these facts along with SC judgement to make its point.

The Mullaiperiyar Dam. Image (C) The Hindu

Maintenance work has not been going on for last 15 years.

Basic maintenance work has been on and it’s only the remaining maintenance work on baby dam that has been stalled due to non cooperation since 96. The SC judgement on this and foisting of false case using Kerala forest department need to be pointed out.

Further it is pointed out that in year 2000, following an elephant’s death due to electrocution after tangling with a power cable, power supply was cut to dam, quarters and Tamil Nadu Public Works Department ran the show with diesel generators.  It was post 2006 judgement; Tamil Nadu requested a cable connection as alternative and made payments towards the same.

Tamil Nadu also points out that the life of Tamil Nadu engineers is very difficult out there and these personnel were harassed and jeered at and that no cooperation was extended, forcing them to shift their families.

It is also pointed out that there are still hurdles and SC had to be approached in April 2011 to seek permission to do maintenance without hurdles.

Recently water resources chief engineer of Kerala reported that that the seepage through the ‘Baby dam’ next to the main Mullaiperiyar dam was ”serious.” 

The maintenance work on baby dam and earth bund was never allowed to be completed and hence this is ironical statement.  Even though this strengthening work is only minor in nature, baby dam receives flow only when dam exceeds 112 ft.

 Hence baby dam flow is only 24 ft when dam is at 136 ft.
Baby dam and earthen bund have been cleared for safety even when level of MP dam is at 142 ft and strengthening is required only for rising the level above 142ft. Hence at 136 feet it’s safe. Last time MP dam reached 136 feet was in 2000 and has reached 136 feet again only this year.

A new dam can be built and Kerala will give Tamil Nadu water.

Tamil Nadu is not agreeable to this.

This means the ownership and operation of dam is out of the state’s control. Tamil Nadu is not ready to let go of ownership given that previous commitment on increasing the level once strengthening is complete wasn’t honoured. Nor was the SC judgement respected. This along with water sharing rulings not being respected across India, means Tamil Nadu is simply not ready for this.

Tamil Nadu also objects that new dam proposed 350 m downstream is at a level 50ft below the base of MP dam and that the tunnel canals to draw water towards Tamil Nadu are at 104 ft level of existing MP dam.  Tamil Nadu says for this the proposed dam must be minimum 154ft and that only 194 ft gives it a good head.

Tamil Nadu has initially pointed out that it is willing to consider a new dam if it gets ownership and control and that Tamil Nadu was prepared to part with power from dam.

It is Kerala’s resource and hence no new agreement can agree for ownership of new dam.

The argument once again goes to validity of agreement and SRC issue.

The argument goes on that since it is Kerala which claims that the dam is not safe despite the SC appointed independent committee clearing safety measures the state of Tamil Nadu must at least get the same lease contract on rights and ownership of the dam. (Tamil Nadu will bear expenses towards building the new dam, if it comes to that)

As per the Ministry of Water Resources a representative of Kerala stated in a meeting that the Govt. of Kerala also recognizes the established uses of water from the dam by Tamil Nadu as per the existing agreement between the two States and will continue the same after the construction of a new dam.

Tamil Nadu agreed to consider the proposal when it was formally sent to them and had requested Kerala to do the same.  The Government of Tamil Nadu though developed cold feet and so did Kerala. In its comments to minutes said that the above proposal was unacceptable and that it had merely mentioned in the meeting that ‘Kerala is willing to give water to Tamil Nadu.’

Dam is not safe as per reports of IIT Roorkee to seismic effect.

Seismic effects have been considered in design changes as is evident from CWC report. Tamil Nadu alleges IIT Roorkee report is not acceptable as they are funded by Kerala post SC order with a view to tarnish CWC report and create panic in people.

The 118 year old Jaswanth Sagar dam collapsed and developed cracks in 2007 causing floods. The same IIT Roorkee had guided the engineers in the Jaswanth Sagar reconstruction earlier.

 Dam collapse will cause 35 lakh people to die.

According to Kerala’s submission in SC regarding free capacity of Idukki dam is that maximum levels have been reached at the MP dam only thrice in its history, that even 136 ft is not being reached easily nowadays.

 The reply notes that MP dam’s current capacity at 136 ft is just 10.5 tmc contrary to 15 tmc full capacity.  Hence Idukki,Kulamavu and Cheruthoni dams are capable of storing the waters comfortably.

 The waters of dam following its break, should it ‘break’, will take a minimum of 4hrs to reach Idukki dam, which is around 50 km away, and would have only a pressure or force of 3 feet per second. Hence there is no danger to the three dams.

 With regards to the flow between MP and Idukki dam reply notes the settlements are 2,743 ft above sea level while the flood flow will be at 2,450 ft above sea level. Hence very few families will be affected and not 35 lakhs as being made out.

(Coming up: The real intentions and conflict resolution)