T. Shivaji Rao, Director, Centre for Environmental Studies, GITAM University, Visakhapatnam, has sent a memorandum to Tamil Nadu Governor K. Rosaiah calling for action to prevent a man-made catastrophe from impending collapse of the Mullaperiyar dam.
The Director said that the Mullaperiyar dam did not meet modern safety norms and was under-designed for hydrological safety. If the Mullaperiyar dam collapsed, it will cause not only loss of lives of lakhs of people but also an economic disaster affecting the two States and the nation. Lakhs of acres of agriculture land in Tamil Nadu would become barren for want of water.
In a press statement, Mr, Rao said that the Mullaperiyar dam did not fulfil three goals of public safety, “The first goal is based on the geological foundations, seismic potential and seismicity of the area. The second goal pertains to structural safety of the dam based on maximum credible earthquake including hydrological safety and spillway design flood. The third safety goal for the dam pertains to the environmental safety that comprises on risk analysis, dam break analysis, emergency response, disaster management including emergency evacuation plans and cost benefit analysis. In the case of the 116-year-old Mullaperiyar dam, none of these safety criteria was considered.”
He said that the dam could not withstand the stresses resulting from peak ground accelerations due to a 6.5 magnitude earthquake at a shallow focal depth in close proximity of the dam. Even a strong Koyna dam cracked in some parts in 1969 due to an earthquake of 6.5 magnitude and caused serious damage.
The Mullaperiyar dam was designed for historical maximum flood is 86 lakh cubic feet per second (cusecs) and the design flood for spillway discharge is 1.22 lakh cusecs. However, the extreme flood magnitude in terms of safety works out to 2.44 lakh cusecs based criteria published by the International Commission on Large Dams.
“Since Mullaperiyar dam is thus under-designed both from seismological and hydrological safety aspects this dam is inevitably bound to collapse irrespective of the pronouncements of the engineering experts who could not stop the collapse of more than 40 dam bursts in India including the masonry dams of Tigra in Madhya Pradesh, Kundali in Maharashtra, Chickhole in Karnataka and Kadhakwasla in Maharahstra.”
He said that Tamil Nadu was failing to read the writing on the wall for want of dam safety studies and was indirectly promoting man-made catastrophe like the Bhopal disaster in spite of the forewarnings.
“Since Mullaperiyar dam is a prescription for disaster it must be prevented by the whole nation by exerting pressure on the Prime Minister to resolve the problem by building a new dam even without dismantling the existing dam by forming a corporation on the lines of the one used for building Tehri and Sardar Sarovar Project.”
Keywords: Mullaperiyar dam row