Wednesday, January 4, 2012

The case for a new dam

N.K.Premachandran, former Minister for Water Resources, in the erstwhile LDF Government of Kerala, has presented his arguments for a new dam in the Op-Ed published in 'the Hindu' of January 3, 2012.

His main arguments are summarized below:
1. Kerala's apprehensions about the dam's stability:  From the lime-surki concrete used as construction material, 3500 tonnes of lime have been washed away during the course of over a century.

2. Strengthening done by Tamil Nadu (with 542 tonnes of concrete) cannot guarantee the structural stability of the dam.

3. The dam lies in a seismic zone. The structure would collapse in the event of a Magnitude 6 earthquake (reference: Dr. Arun Bapat and Dr. D.K.Paul, of Earthquake Engineering Department of IIT, Roorkie: 'Structural Stability of Mullaperiyar Dam with Regard to Seismic Effect')

4. The dam is hydrologically unsafe (Dr A.K.Gosain of IIT, Delhi) based on 'Probable Maximum Flood Estimation and Flood Routing of Mullaperiayar Dam'.

5. Disaster Impact:  Idukki dam cannot contain the flood water in the event of Mullaperiyar dam collapsing.  The combined storage of both dams crossed the FRL (Full Reservoir Level) in 1981, 1992, 1994, 1998, 2005 and 2007. Idukki would overflow and its stability would be under serious jeopardy.

A disaster would impact 1.5 lakh people living between Mullaperiyar and Idukki dam and 35 lakh people in the river basin downstream.

The permanent solution to avert disaster (using 'precautionary principle')  lies in constructing a new dam. This was decided on January 25, 1979 in the meeting with CWC Chairman:
'A joint team of engineers from Tamil Nadu and Kerala will explore the possibility of locating a new dam within a reasonable distance from the existing dam." An agreement was signed by officials from Kerala and Tamil Nadu on Dec 20, 1979 to that effect and approved by CWC

1. The present dam will be left intact without disrupting water supply to Tamil Nadu during construction of new dam.  Kerala has passed a resolution to continue supply of water to Tamil Nadu.

2. After completion of the new structure, the old dam will be decommissioned.

The questions/issues that remain are:
-Who will have ownership, control and custody of the new dam
-What happens to the existing agreements?
-What will be the terms and conditions of water sharing?
-What will be the cost and who will bear the cost?
-What is the timeline for completion of the work?
-Who will be responsible for the construction?
-What will be the impact on the environment, particularly the Periyar Tiger Reserve and wildlife?

-Joseph Ponnoly


John Tharakan said...

Hi PJ,
With the discussion on the Mullaperiyar Dam raging, I recall a historic reality etched in my mind: Godavari Floods of 1986, August 14-16. Our relief work sowed the seeds of PARA.
Sir Arthur Cotton who built the barrage at Rajahmundry over the Godavari had wanted it to be renewed after 100 years. The Indian Government did the renovation. The Engineers who built the dam or the committee that evaluated the old dam or the politicians or all of them together decided that the canal outlets and navigation lifts and related construction at the two extremes of the 8+ kms long barrage were strong enough and did not need renovation. Come 1986 floods and the non-renewed sections at Vijjeswaram and at Dowleswaram were washed off. The floods, the biggest in living memory, were caused by the confluence of excess monsoon rains and floods in the catchment area, flash floods near the barage area because of cloud burst and high tide preventing water from flowing into the sea. A perfect receipe for disaster: humans and nature in collusion. 340 people died according to official records. Fortunately the engineers of the day woke up to read the suggestions Sir Cotton had made for such eventualities and breached the river banks at Polavaram and saved Rajahmunry and its thousands who would have been washed away by the floods. Villages from polavaram to the sea were washed off, including 8kms of the Chennai Kolkata national highway near Tanuku.
TD John

Anonymous said...

Can you please upload a copy of the Anand Committee report on the mullaperiyar?

News Video- Mullaperiyar

1928 St Francis Dam Failure and Flood