Mullaperiyar dam break analysis: area of submergence

Much of the discussion in the Dam Break Analysis (Mullaperiyar to Idukki reservoir) done by the Indian Institute of Technology, Roorkee, is about the height and speed of the water flow in case of failure of Mullaperiyar dam. As to the lives of people living downstream of the dam, it matters little whether the water would be flowing in at a height of 40 metres or 20 metres or with a velocity of 40 kilometres a hour. Even water flowing at, say, ten km an hour and a few metres high will claim lives. But width of the flow matters as that determines who all living near the river course would be affected.

The analysis shows that the top width of the flow would be less than 300 metres for the first 30 km of the path of flow along the river course. For the rest of the 15 km before reaching Idukki reservoir, the top width exceed half a km only at two points. However, the accompanying inundation maps show that water could spread out in low lying areas.

The study does not say anything about the chance of small hills or elevated portions on the sides of the river course being breached and water flowing into Pathanamthitta district.

Given below are the inundation maps. They are photographs of the original map prepared by the IIT. The image is not to scale because of distortions resulting from placement of the map and camera perspective. Locational information may be visible only in terms of longitudes and latitudes in the photo except for a few place names such as Vallakkadavu, Vandiperiyar and Upputhara. (The original map is a larger one plotted against a top sheet of 1:25000 scale.)

Dam break analysis

Map showing area that would be inundated by dam break flood from Mullaperiyar

Split Map 1:

Mullaperiyar- inundation-Upputhara

Map showing area at Upputhara that would be inundated by dam break flood from Mullaperiyar

Split Map 2 Mullaperiyar-inundation-Vandiperiyar

Map showing area at Vandiperiyar that would be inundated by dam break flood from Mullaperiyar

Analysis and discussion of results forming part of the Dam Break Analysis.
Mullaperiyar Dam break analysis by IIT Roorkee in full

Mullaperiyar: behind the veil

It seems that the Inter-State Waters wing of the IDRB under the Irrigation Department has something to hide regarding the way it commissioned studies and presented facts before the Supreme Court.

In the case between Mullaperiyar Environmental Protection Forum v. Union of India and Others decided On: 27.02.2006, Kerala had failed to present its case properly and forcefully. This even resulted in the Mullaperiyar dam being recorded in the judgement as a masonry dam instead of as a composite dam. This weakened Kerala’s case because masonry dams, in general, have a longer life. Problems specific to Mullaperiyar, its structure, quality of the lime-surkhi mixture used and causes of weakness were never elucidated before the Court with supporting material. Kerala even failed to challenge Tamil Nadu’s contention that the waters from Mullaperiyar would be contained in Idukki reservoir in case of a failure of the former.

The judgement said: “Further, it is pertinent to note that the dam immediately in line after
Mullaperiyar dam is Idukki dam. It is the case of State of Kerala that despite the ‘copious
rain’, the Idukki reservoir is not filled to its capacity, while the capacity of reservoir is
70.500 TMC, it was filled only to the extent of 57.365 TMC. This also shows that
assuming the worst happens, more than 11 TMC water would be taken by Idukki dam.

It seems that nobody seemed to have cared to tell the Court that there are about 50000 people living between Mullaperiyar and Idukki who would be killed in case of breach of Mullaperiyar dam. (Analyses show that about 8800 houses would be submerged). Did the Court think that the area downstream of Mullaperiyar were all forests, given that the State’s arguments were all about disturbance to animals in the Periyar Tiger Reserve from raising of the water level? Why did Kerala make a case of Kerala that Idukki reservoir was filled only to the extent of 57.365 TMC, especially when the facts were to the contrary?

Kerala seems to be lackadaisical in efficiently and ably arguing the present case before the Supreme Court (filed by Tamil Nadu challenging Kerala’s law that mandated that the reservoir level of Mullaperiyar dam should not exceed 136 feet for safety reasons). Several of the studies commissioned by the IDRB were done in a hurry at the last minute. Studies like that on the Ecological Impact Assessment of Water Level Increase at Mullapperiyar Dam were full of wrong assumptions and errors.

When it commissioned a study by IIT, Roorkee, on the threat posed to the dam from earthquakes, there was hardly time to complete in time. The first draft was full of factual mistakes and none from the IDRB was willing to quickly go to Roorkee and get the errors corrected. By the time the Department forced someone to go and the final version was readied, it was too late. The Court did not accept that as the time for producing evidence was over. A dam break analysis was not in sight even then.

The dam break analysis was quickly commissioned when the Empowered Committee of the Court was seized of the matter. Though Committee’s term is about to expire, only the first part of the study is over. The IDRB is refusing to divulge the full details of the study to the public. Tactics were raised to prevent furnishing of the documents relating to the analysis and material produced before Court. I reproduce below the details of the RTI request and response of the Department.

The following documents were requested under RTI Act:

  1. Copy of dam-break analysis /inundation study for Mullaperiyar done by IIT, Delhi.
  2. Copies of submissions, statements, argument notes and affidavits made by Kerala in the Mullaperiyar case filed by Tamil Nadu (challenging Kerala Irrigation and Water Conservation Amendment Act) before the Supreme Court and its Empowered Committee.

The reply from the Office of Chief Engineer was as follows:

An appeal was filed against this as follows:

Roy Mathew
F-42 RBI Staff Quarters
Plammoodu, Pattom
Trivandrum 695 004

Appellate Authority under RTI Act
Office of the Chief Engineer (ISW)
IDRB, 3rd Floor, Vikas Bhavan
Trivandrum 695033

Sir,

Sub: Appeal on decision of State Information Officer on request for supply of documents regarding Mullaperiyar case, regarding,

Ref: Letter No. IDRB/ISW/AD2/2594/2010 Vol V from Public Information Officer dated February 29, 2012.

  1. The request for copy of dam break analysis is rejected on the ground that the IIT Delhi had not conducted such as a study on Mullaperiyar dam. The reference to IIT Delhi was only an error in the request which was otherwise clear. Section 5(3) of the RTI Act specifies that the PIO should render reasonable assistance to persons seeking information. So, it is imperative that the PIO should have pointed out that the study was done by IIT Roorkee and proceeded to supply the information. The PIO has thus infringed the Act in letter and spirit. Hence, I request you to order immediate supply of copy of the analysis done by IIT Roorkee.
  2. The Sections and subsection quoted by the PIO in rejecting my application for copies of submissions, statements, argument notes and affidavits made by Kerala in the Mullaperiyar case do not exist. However, I assume she is referring to sub clauses of Section 8 (1). Affidavits and other documents submitted to the court are public documents once it is filed before the court. Hence, there is no ground for rejecting my request under 8(1). Moreover, the strategic interest referred to in Section 8 Clause (1) Sub clause (a) of the Act refers to the sovereign State of India in relation to foreign States and not to states of India such as Kerala or Tamil Nadu. Section 8(1h) do not apply as no prosecution or apprehension of offenders is involved in the Mullaperiyar case.
  3. In view of these above reasons, I request you to set aside the objections raised by the PIO and order release of the information without any further delay.

 

Trivandrum                                                                                                      Yours truly

9-3-2012                                                                                                          Roy Mathew

 

The Appellate Authority did not respond directly to the points of appeal. Instead, it came up with a new argument that the dam break analysis has not been completed.

Apparently, the Department did not want the public to know how it is fighting the case and the quality of studies being commissioned by it. So, Expert-Eyes will be making efforts to bring these materials to the attention of the public. Though the Department is refusing to provide the material, we have the executive summary  and conclusions of the  dam break analysis and more at http://expert-eyes.org/mullaperiyar/index.html

Let the experts have a look at it.

 

“News is what somebody somewhere wants to suppress; all the rest is advertising.”

 Lord Northcliffe