Mullaperiyar Dam technically dangerous, but no need to panic
While the 117 year old Mullaperiyar Dam is technically very dangerous calling for de commissioning, it is illogical for the people of the area to panic of any imminent danger, says the Forum of the Civil Engineering Post Graduate Scholars. A discussion organized by the forum observed that relevant technical parameters are overlooked by even the so called experts.
Erroneous factors
The Probable Maximum Flood (PMF), an important parameter to evaluate the danger posed by dams arrived for the area is a gross example for erroneous fixing of important values. A technical body like the Central Water Commission has accepted the figure arrived by Tamil Nadu ignoring the accepted principles to fix the value, said Ananth R Krishnan of the National Institute of Technology(NIT), Soorathkal in the key note address in the event. The value fixed is 6003 cumecs. This is less than even an actual observed peak flow in 1943 when the flow was as high as 8453 cumecs. The world standards take the probable maximum value for 1000 to 10000 years and the figure above ignores an occurrence just 60 years ago. For all other areas in India CWC has fixed a PMF much above any observed values. For example for Machu- II Dam, Gujarat the observed value was 13421 cumecs and the PMF fixed was 26420 cumecs.
Highest masonry dam
This happens to be one of the highest masonry dams of the world. In India the53.64m high Mullaperiyar Dam is the highest masonry dam among those more than 100 years old and the second highest dam 40m high Khadakwasla has already failed in 1961. Now there is no other dam of this kind in India of even half the height of Mullaperiyar dam. Thus the dam has no comparison to assess its danger. A number of dams with about half the height of Mullaperiyar dam has toppled worldwide in the last century. The failure of 27 m high Kantalai dam in Sri Lanka in 1986 is a recent example. Ananth R Krishnan said.
The dam is made of rubble masonry in lime, surki and sand mortar with a core
Erroneous factors
The Probable Maximum Flood (PMF), an important parameter to evaluate the danger posed by dams arrived for the area is a gross example for erroneous fixing of important values. A technical body like the Central Water Commission has accepted the figure arrived by Tamil Nadu ignoring the accepted principles to fix the value, said Ananth R Krishnan of the National Institute of Technology(NIT), Soorathkal in the key note address in the event. The value fixed is 6003 cumecs. This is less than even an actual observed peak flow in 1943 when the flow was as high as 8453 cumecs. The world standards take the probable maximum value for 1000 to 10000 years and the figure above ignores an occurrence just 60 years ago. For all other areas in India CWC has fixed a PMF much above any observed values. For example for Machu- II Dam, Gujarat the observed value was 13421 cumecs and the PMF fixed was 26420 cumecs.
Highest masonry dam
This happens to be one of the highest masonry dams of the world. In India the53.64m high Mullaperiyar Dam is the highest masonry dam among those more than 100 years old and the second highest dam 40m high Khadakwasla has already failed in 1961. Now there is no other dam of this kind in India of even half the height of Mullaperiyar dam. Thus the dam has no comparison to assess its danger. A number of dams with about half the height of Mullaperiyar dam has toppled worldwide in the last century. The failure of 27 m high Kantalai dam in Sri Lanka in 1986 is a recent example. Ananth R Krishnan said.
The dam is made of rubble masonry in lime, surki and sand mortar with a core