Mr. Gupta: "I have the duty to flag one aspect- in the first writ petition, respondent three is Central water commission, which is the Union of India. The fourth respondent is the supervisory committee appointed by this court. There seems to be no representation filed on behalf of the supervisory committee. The same AOR as for the Central water commission has filed a representation on behalf of the supervisory committee. The committee is a bipartisan committee- it has members of the states of Kerala and Tamil Nadu and it is presided over by the CWC member. We have found that respondent no. 4 has not taken a bipartisan approach on this matter. The Kerala member has given a letter saying that no decision was taken by the committee to appoint (...) as the advocate on record for the respondent no. 4"

Justice Khanwilkar: "How does it matter? If we need assistance, we will treat him as an Amicus Curiae. To the extent he is taking a particular position, you are there to correct us"

Mr. Gupta: "I am not raising any issue with regard to that right now"

Justice Khanwilkar: "Everybody should examine the matter with a broad approach and open eyes, it is not adversarial"

Mr. Gupta: "Yes, all of us are citizens of India. If any one of us is in danger, then whoever is the authority would be concerned. This is not about any two states"

Continuing, he began to make submissions on the brief facts of the dispute- "The dam is at a moderately high altitude. The submergence area is all forest surrounded (indicates from a picture of the dam)...In the Cauvery matter, I had made a query to my clients as to how you define a basin. It is done by using a contour map. Every height is shown in different contour lines, the heights of those contour lines around the river will be the limit of the basin because if water falls beyond that point, it will go into some other basin. The importance of the basin of the river is that all water which comes into that area will move towards that river and that is why it is also called the catchment area. The second thing is that this 114 sq. km of the Periyar river catchment area which falls in Tamil Nadu makes it an interstate river. So the jurisdiction of the state Supreme Court depends on that. The Tamil people call it the Mullai Periyar which is the name of a flower 'jasmine' and the Kerala people call it based on the Mullayar river and Periyar river- Mullaperiyar. It was constructed between 1886 and 1895 in the Idukki district of Kerala state in an area leased for 999 years by the Secretary of State for India by the Maharaja of Travancore. The dam is one of the oldest and highest gravity dams of its nature currently existing in the world. It is a highly composite dam which cannot be analysed theoretically using any existing national or international model. There are different kinds of dams-masonry dam, earth dam, concrete dam. It is a masonry dam to which a concrete structure has been added so it is a heterogeneous dam"

"Water is taken from the Periyar basin and goes to Tamil Nadu to irrigate and for the drinking water and power supply through five districts of Tamil Nadu which are drought prone districts. This is not a dispute relating to the sharing of waters. There is no dispute that this water is to go to Tamil Nadu. The nature of the dispute relates to Dam safety only. Kerala is before your lordships saying that the dam is not safe as it stands. Safety depends upon the height of the water in the reservoir. Higher the level of water storage in the dam, two things happen- one is that there is more pressure on the dam as there is more volume of water pressing against the dam and therefore it affects safety; Second, there is less space at the top to hold water. If the water level keeps rising, it has to be discharged or removed from the dam, from the reservoir. There are only two ways of removing water from this reservoir- to send it downstream by lifting the spillway gates, or take it through the tunnels. Sending it downstream is more damaging as it becomes an uncontrolled operation when it is allowed to spill downstream", he continued.

Next, Mr. Gupta took the bench through the essential dates- "29th of October 1886 when the Periyar lease agreement was signed. 29th of May 1972, supplemental agreements were signed and Tamil Nadu, in one of them, surrendered fishing rights to Kerala. They were given for the first time the valuable right to generate power. On 25 November 1979, the Central water commission agreed that Dam safety was compromised and strengthening measures were required. Water level at the reservoir was to be kept at 136 feet pending measures. Then an expert committee was constituted and on 16th of March 2001 the expert committee recommended raising the level of water in the reservoir to 142 feet. Disputes arose. 27 February 2006, the disputes which arose reached the Supreme Court and by its first judgment reported in 2006 3 SCC 643- Mullaperiyar Environmental Committee v. Union of India- it was held that the level was to be raised to 142 feet and that after completion of strengthening works, independent experts would examine the situation before water level would be allowed to be raised further. 18th of March 2006, the state of Kerala amended what was known as the Kerala irrigation and water conservation act of 2003 which allowed Kerala to control the level of water in the dam in public interest. Tamil Nadu filed a suit here in 2006 because it is an interstate river. This was referred to a Constitution bench on certain specific issues. 18th of February 2010, the Constitution bench set up an empowered committee. 23rd of April 2012, the Empowered committee submitted its report. After complete hearing of the suit, on 7 May 2014, the Constitution bench delivered its judgment reported at 2014 12 SCC 696. It held that the lease is valid for 999 years; secondly, the suit was maintainable; thirdly, the amended act in its application to Mullaperiyar Dam was in violation of separation of powers, that it encroached upon judicial powers in seeking to overrule the 2006 judgment and hence, it was struck down; fourthly, Committee to supervise restoration of water to 142 feet and to take emergent measures for dam safety was set up"

"On 11.1.2018, a writ petition had been filed called Russell Joy v. Union of India. This court gave directions for preparedness of disaster at Mullaperiyar [2018 3 SCC 179]. On 16 August and 17 August, in the light of extreme rainfall, the Supreme Court gave directions in the Russell Joy matter to initiate measures to prevent flooding and assuage fears of people living downstream and bring down the water level in the dam to 139 feet temporarily...17 August 2020, Joe Joseph petition was filed. Present proceedings started.16 March 2021, directions were given by your lordships to Tamil Nadu to formulate rule curve, gate operating schedule, instrumentation plan. Rule Curve has two levels- upper levels and lower levels. It stipulates what will be the level of water maintained in the reservoir on different dates of what is known as the water year. For water resources, the year is from June to May. Gate operation means in order to maintain that level, we will open and shut gates and what is the method we will follow", he continued.

Mr. Gupta: "For Kerala, there are certain other issues also. We pray that the supervisory committee be reconstituted and its functions widened"

Justice Khanwilkar: "Why?"

Mr. Gupta: "There are no technical persons from the two states in the supervisory committee. We have suggested one technical person from both states in the committee. It becomes a five member committee. We have said the functions should be enlarged. The other issue as regards Kerala which is a long-standing issue is what is to be done in the long run? We have taken the position that the process for setting up a new dam has to start. The new dam will be downstream of the existing dam. Some work is going on for the environmental impact assessment etc"

Mr. Gupta: "Instrumentation is absolutely critical in dam safety. And such instrumentation is absent, which is the sum and substance of my submission. There are two very comprehensive guidelines with regard to the instrumentation standards- one of the Bureau of Indian Standards and one of the CWC. The BIS document states that 'Objectives of instrumentation are manifold. Instruments embedded in dams keep a constant watch over their performance and service and indicate distress points which call for remedial measures'. It says that you are going to be so conservative that even at the maximum water level when the rainfall is at the highest and conditions are at their worst, even at that moment the dam will not break. Extreme positions are taken into consideration, considering the consequence of a breakage of a dam. Even once you cannot allow the dam to break. It is possible for scientists to lay down what to do in a masonry dam and what to do in a concrete dam. But when it becomes heterogenous, there is no model for instrumentation. Instrumentation is more difficult then...In 1886, seismology was not there. So this dam today does not have any measurement of seismicity in the area at all. We said it should be set up, it has yet not been set up. Then there is the CWC document on instrumentation. It is stated that it is imperative that a century old dam should have all necessary instruments for monitoring deformation, seepage/leakage quantity and quality, uplift pressure, pore water pressure, temperature, reservoir level and seismicity, as per the guidelines of Central Water Commission viz. Guidelines for the instrumentation of Large Dams (2018). A Comprehensive instrumentation plan was given to CWC on 25.3.2021. The plan was by Tamil Nadu with the remarks of Kerala. What according to us is the status of the instrumentation- Uplift pressure meters are not working and showing faulty readings. CWC asked Tamil Nadu to justify, but no action has been taken by Tamil Nadu in this regard. Uplift pressure gauges are still inactive...Then there are the Fixed points on top of the dam for geodetic service. Tamil Nadu still has not shared geodetic data with Kerala. In the last supervisory committee meeting of 25.2.2021, the chairman requested representatives of Tamil Nadu to share geodetic data for the last 10 years for checking defection in the dam. Tamil Nadu agreed to provide for the past two years in one month and balance in three months. Tamil Nadu has not done so so far...The installation of seismographs was recommended in 1991 by an expert panel, and it has still not been done after 30 years...No suspended plumb-line for measuring deformation in the tank...No structure for measurement of seepage, the quantity of seepage through the body of the dam now being recorded by government of Tamil Nadu is only a small percentage of the actual seepage water escaping through the dam"

"As per the 2014 inspection report of the CWC, Most of the uplift pressure pipes were likely to be choked or allowing for very little flow of water. Measuring gauges were not showing anything. Although there is a Drainage hole in the gallery, very little flow of water was observed in all the holes...It has been said that 70% of the instruments were inactive, the performance of the dam could not be assessed, and on visual inspection of the dam, it was revealed that some yellow coloured fluid was coming out...At the 14th meeting of the supervisory committee on 25.2.2021, Tamil Nadu repeats that installation of seismicity instruments is still in the process...So serious gaps have been found in instrumentation. Despite this, the CWC in its status report has not taken action against the Tamil Nadu government", he submitted.

Mr. Gupta: "Comments of Kerala with regard to rule curves have not been addressed despite repeated requests. We have an objection to the upper rule curve as prepared by Tamil Nadu and finalised by the CWC. We also prepared one rule curve, which we will place before your lordships. Our points of contention as regards rule curve are that one, while all dams have one peak on 30th of November, CWC has accepted Tamil Nadu's point that Mullaperiyar has 2 peaks- 20th of September and 30th of November. CWC does not accept our curve. Fixation of peak at 142 feet on 20th of September as on the upper rule curve as proposed by Tamil Nadu requires reconsideration. It should be 136 ft, adopting the approach to other dams. If I follow their formula also, then we have 135.9 ft on 20th September which is rounded off to 136. We have altered only one variable that 'don't have another peak on 20th of September'. The other issue is that the peak on 30th of November should be 140 instead of 142. We have suggested that instead of 142 ft, the peak maybe take in at 140 on 30th of November"

Mr. Gupta: "No, there is nothing special about Mullaperiyar. But this allows Tamil nadu to store more water without caring about the pressure on the dam. All other dams are subjected to maximum pressure only once a year but this dam is subjected to maximum pressure twice a year. We are saying CWC Is making a mistake because it is accepting something which is unnatural and is putting pressure on the dam. This feature of two peaks is unique only to the Mullaperiyar dam. To follow a different approach towards Mullaperiyar which is on the same river system as Idukki dam is incorrect and unacceptable. 142 is the full reservoir level- FRL. But in the peak monsoon, if you keep the reservoir level at 142 and if the monsoon continues, it goes above 142. So that is the reason for 140. We have to take the extreme position in these matters because the dam must be fit even in the extreme conditions"

Mr. Gupta: "The real subject matter of this judgment was the challenge to the amendment to the Act of Kerala...Also, circumstances are changed- the Climate change that we are seeing in this very region is such that time has come to review the situation. When Your Lordships said FRL will be 142, it does not mean that it can go above 142 also if necessary. If we actually fix the peak at 142, then it will go above it. If it does so, then the dam will be compromised"

Justice Khanwilkar: "Your submission is that to ensure that it never exceeds 142, 140 would be the benchmark?"

Mr. Gupta: "Yes, that flood-cushion has to be kept. The Dam in its present condition is not good enough to hold water above 142 feet. So Kerala has considered 140 feet to be the upper rule curve level on 30th November. In the empowered committee report, it was said it can go above 142 feet on a transient basis. Your Lordships' judgment, after considering this report, said 142 feet; it did not say anything about above 142 feet. Now the situation has changed and the transient period has gone up to 22 hours from 10 hours. In the case of a '1-in-100-year flood', the water level would be 142 feet for 22 hours"

"But if 140 is taken as the present level, Tamil Nadu is not affected. There is no significant compromise to how much water they get in a year. It is Kerala's stand that we do not want to take water away from Tamil Nadu in following this process", he advanced.

Mr. Gupta: "The schedule will be set after the rule curve is finalised. But the Indian standard operation is that you don't wait for it to reach 142 and that you must open the spillway gate gradually when you see heavy rainfall and inflow"

Mr. Gupta: "These are only principles. But they are not being followed. The gate is not opened gradually but suddenly. These principles have to be taken into consideration. There is mismanagement of the reservoir level on the Tamil Nadu side, ignoring the concerns of Kerala"

Justice Khanwilkar: "Is it not possible to have a joint committee who would supervise this gate operation schedule? That will allay the fears of each side. Both states will be represented in that committee"

Mr. Gupta: "We have suggested that the concerned district collectors from both states would be in that committee. This would help to avoid sudden discharge of water..."

Mr. Gupta: "2 independent technical expert members with expertise in dam management, one from each state, may be added to the supervisory committee so it becomes 5 member"

Mr. Gupta: "Yes. And the CWC is headquartered in Delhi. You cannot expect them to look after everything at all times"

Justice Khanwilkar: "Multiple institutions overseeing things may also lead to confusion..."

Mr. Gupta: "Two things have changed since 2014- time has passed and therefore, the dam has further weakened. And secondly, there has been a change in climatic conditions from 2017 onwards...In 2017, Kerala was hit by landslide episodes, catastrophic floods and cyclonic storms. This raised concerns about changing rainfall patterns- the hydrology has changed since the pronouncement of judgment in 2014. The issue is whether one should continue strengthening the dam and lifting the water height or one should look at a new dam...The only permanent solution for removing the eternal threat is renewed dam designs as per model standards. Merely taking strengthening measures is not sufficient".

The hearing will continue tomorrow.