The Koyna earthquake in Maharashtra took a death
toll of about 200 people on this day 50 years ago. Though the earthquake caused
only minor damage to the Koyna dam and some houses in the vicinity, it is
perhaps the only scientific event in India which affected science, society and
engineering. Till the quake, peninsular India was considered aseismic and most
big civil engineering projects were constructed under this assumption.
For the engineering community, the Koyna accelerogram - which had recorded 0.67 g acceleration - was a boon. This was the first accelerogram in India. Prior to this, most dam engineers and designers were adopting the Californian accelerogram for design purposes. This has been used for the construction of several dams, atomic power plants and refineries in India.
Immediately after the earthquake, there was no scientific explanation for the seismic contingency. Some observations were made by scientists, engineers and the common man. The educated community, which included the scientists and engineers, said the event could be studied properly. They found that the area and the Konkan region had been experiencing earthquakes and that one such quake had occurred around 400 years ago. However, their observations were totally eclipsed by the wild imagination of the common man.
The strong belief was that the construction of the Koyna dam was the main reason behind the earthquake. A new acronym, RIS (reservoir induced seismicity), was coined. Advocates of this theory proposed two possible causes for the quake: one, water in the reservoir had trickled down and lubricated the underground fault causing the quake and, two, the weight of the water in the reservoir was far higher than the loadbearing capacity of the rock. A number of seminars, conferences and functions on RIS were held during subsequent years. Some narcissistic scientists also joined the RIS bandwagon without realising that they were batting on a weak wicket.
The two hypotheses were negated with scientific facts. When the lake-tapping experiment was conducted, it was found that there was no water or moisture in the rock. Computer programmes were run to find the effective load on the rock. It was found that the load due to the water body was around 3.5-4 kg per sq ft - far lower than the loadbearing capacity of the rock. In fact, the late Dr K L Rao, an eminent engineer, scholar and then Union minister, compared the Koyna reservoir sitting on the rock to a fly sitting on an elephant.
With RIS being unacceptable to a large number of scientists, it was renamed over the years as RAS (reservoir associated seismicity) and RTS (reservoir triggered seismicity) before being finally abandoned.
Apart from the debate it triggered among seismologists, the Koyna earthquake caused severe damage to the credibility of irrigation development and dam technology. Taking a wrong cue from the earthquake, the Narmada project was challenged in various courts and protest marches were held in several cities. The project was delayed for 11 years before it could be commissioned.
Likewise, the construction of the Tehri dam was also opposed. The main reason for opposing the project was, again, that it might induce an earthquake. Now, whether a dam is constructed or not, the Himalayan region will always have some earthquake activity. I remember visiting several hydro-electric projects in the country to install seismological instruments in and around the dam or project area.
After their failure to block the Narmada and Tehri projects, the protesters took their opposition to the Subansiri dam in Assam. Here, the protest took a somewhat dangerous turn bordering on violence. The protesters even sat on the rail tracks to block a train carrying equipment and machinery for the construction of the dam.
It has now become almost regular practice
to object to the construction of dams, irrigation projects, hydro-power
projects or atomic power plants. Considering the increasing demand for power,
we need more dams and hydro-electric and solar power generators.
Presently,
some Himalayan states such as Sikkim, Uttarakhandand Himachal
Pradesh are developing mini, micro
and medium hydro-electric projects. In addition, Bhutan and Nepal are providing India with a good amount
of electricity generated at hydro-electric projects. In the Sahyadri
mountainous region of Konkan in Maharashtra, about 2,200 sites have been
identified for micro hydel power projects similar to Himachal Pradesh. But
neo-environmentalists are opposing these projects saying they would have an
adverse impact on the environment.
In fact, opposing developmental activities happens regularly, be it over the construction of a flyover in the Malabar Hill area of Mumbai, road-widening in a city or building of an airport or highway. People oppose projects and fight a legal case right up to the Supreme Court, which leads to a delay and rise in project cost.
I sometimes wonder whether this trend to oppose projects had its root in the aftermath of the Koyna earthquake. However, wise men try to convince me that the opposition is mainly politically motivated. Contemporary history tells us that till 1975 or so, no developmental project was opposed. I remember how the Bhakra and Hirakud dams, which Jawaharlal Nehru had announced as new temples of development, were jubilantly welcomed by everybody.
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