SOLUTION TO MULLAPERIYAR DAM

T.Shivajirao,

Director of Environmental studies,
 Gitam university,visakhapatnam.

http://kaumudiglobal.com/innerpage1.php?newsid=13080 [ damaging impacts of dam burst]

http://expert-eyes.org/mullaperiyar/dam_break_analysis.html[ dam Break analysis.IITreport]

Periyar  river originates in sivagiri hills in kerala at an elivation of 1830 meters above sea level(M.S.L.) and travels Northwards and joins Mullayya river at an elivation of 845 meters and then flows Westwards and 13 km  down  is built 1200 feet long and 150 feet high Mulla periyar dam  with rubble miserly with lime surke motor (2:1:3) . Later the dam was strengthened with Rcc capping and top of the dam + 10 feet thick concrete backing was layed on the down stream side of the dam. But the joint  between  concrete layer and old dam is not grouted and hence it is not an integrated but a composite dam.

An either side of the dam there are depressions or saddles .The left saddle is filled with a masonry dam 240 feet long and 47 feet  high and is continued with an earthen bund for 243 feet . This baby  dam is a solid gravity dam similar to main dam. They right saddle is used for surplus escape with 10vents of 36ftx10ft and also 3 vents of 40ftx10ft with crest level at 136ft .  The FRL of 144ft in 1886 was changed to 152ft without consent of Travencore. FRL was reduced to 150ft in 1964, 145ft in 1978 and 136ft in 1979 due to safety concerns. Annual inflow is 23.5 TMC. Tamilnadu diverts annually through open cutting of 5342 ft channel of 21ft width. Tunnel  is 12ft high and 5887ft long and discharges 2100 cusecs through 150sq.ft section. Forebaydam  has 3.2 Mcft capacity and from there water  is taken through a power tunnel 3992 feet long with discharge 1600 cusecs 4 penstock pipes take 400 cusecs  to power house generating 500 million units of electricity annually.

Tail waters go into vairavanar a tributary of suriliyar river, another tributary to vaigai river. Vaigai water is given to Agriculture for 90,000 acrers for the first crop and 60,000 acres for second crop.

Recently there is a controversy about the safety of the dam because its life span of 50 years estimated by nthe old Engineers expired and it is 117 years old it is showing signs of decay and so morter from the masonry dam is pealing out and water is oozing out of the small cracks and joints of the dam. Keralites fear that the dam will burst soon and the consequent floods will kill 40 lakhs of people downstream due to flash floods. So Kerala state wants to build a new dam about 1 km below the old dam and thus protect the lives of Keralites. But Tamilnadu is apposing the move stating that the farmersof Madhurai region may be deprived of there irrigation water from Mulla periyar  because they  suspect  that Kerala state may give higher priority for diverting the river water to iddukki dam for producing more electricity and there by  Tamilnadu may not get enough water for irrigation in the right time . When the cases were failed on the dam safety,  the suprme court appointed expert committees to study the problem. The experts told the court that the dam is safe and the supreme court ordered that Mulla periyar dam FRL can be raised from 136 ft to 142ft initially and after repairs,  to 152feet. Kerala does not agree with this view. Hence people of Kerala and Tamilnadu are fighting against eachother on the issue. Unless this problem is solved immediately both the states are bound to face manmade disasters, costing several crores of rupees damage and loss of lives of people and animals.

.  Solving Mullaperiyar problem

Mullaperiyar dam presently holds about 15 TMC of water in the reservoir with about 5 TMC as dead storage at about the level of +104ft which is the spill level for the tunnel that carries periyar water into Tamil Nadu. The dam has a top level at +152ft. Kerala is insistisng on keeping the reservoir water level of at +120ft for ensuring safety of the dam. Supreme Court has directed Tamil Nadu to strengthen the dam and increase the water level to +142ft. which ultimately may be taken to +152ft. and thereby the water storage will be increased. So that more water can be diverted into Tamil Nadu for increased use for agriculture and hydropower generation. Now without disturbing the existing Mullaperiyar dam, the water storage can be increased to a higher level by using cloud seeding experiments which are successfully done in China by using more than 30,000 of technicians who operate the cloud seeding machinery to obtain about 1800 TMC of extra annual rainfall at a cost benefit of 1:29. When Chinese are able to get extra water like the Americans by cloud seeding since 1960 why should not the intelligent Indians demand their Chief Minsters to visit China and Australia to observe these modern technologies for augmenting annual rainfall and prepare suitable reports for implementation in India. The Government of India may be forced to give a directive to the Indian Meteorological department to promote cloud seeidng operations in all the states for augmenting annual rainfall and thereby promote agriculture on sustainable basis for the economic growth and development of all Indian states. Dr.Jayalalitha as an intelligent political leader of Tamil Nadu must take the inititive and visit China along with some other experts who conducted these experiments in states like Maharashtra and Andhra Pradesh for over 5 years from 2004. 
It is utterly wrong to blindlybelieve that Mulla periyar dam is srructurally, hydrologically, and seismically safe. Even the supreme court Judgement on the safety of the old dam is entirely wrong from scientific and techniological angles.

. During the rainy season there could becyclones and intense rainfall and consequent floods may cause novertopping of the dam resulting in its collapse.The consequences of such a dam burst maycause the killing of

40lakha of people in Kerala and even theTamilnadu state is bound to lose its right for the entire water from the periyar reservoir for ever. In order to avoid this impending calamity we must advise both the states to construct about three to four Barrages within the periyor reservoir to store upto 5 t.m.c. of water in each ofthem and ensure that the existing old dam retains 5 t.m.c. Even if the dam fails the disaster will not cause unbearable damage to Kerala and Tamilnadu states.

Mullaperiyar waken