(detailed explanation not according to the parameters of word limit)
Devastating river floods have occurred in the past across the world, causing severe damage to life and property. Currently, 21 million people globally are affected by river floods every year (this figure may reach 54 million by 2030); India has the highest number of affected, at 4.84 million people, followed by China (3.48 million) and Bangladesh (3.28 million)—compare that to the US’s only 167,000. The flurry of river floods during the last 2-3 decades has brought to the forefront the question: Are dams causing floods? The recent floods in Kerala seem to strengthen that view.
At the first instance, this may not be true—because traditionally dams are considered as providing protection against floods, along with other benefits like generation of electricity (clean energy), irrigation and recharging of groundwater, etc, for socio-economic development of a country. Thus, it’s necessary to examine carefully, and scientifically, the real causes of river floods. Let’s assume that dams do cause floods. Then, should we put a moratorium on construction of dams and explore other alternatives to fulfil our requirements that dams are meeting today?
Suppose we do that in India, then what next? Taking the example of compensating for electricity generation, which dams provide us currently, we have to further enhance production of solar and wind energy—which we can do as there is abundant sunshine and wind in India, though at the cost of huge investment and the long time required. But can we be sure that solar and wind energy will not lead to any harmful effects in the future?
The answer is ‘no’. Today’s boon can become tomorrow’s bane—consider Industrial Revolution of the 19th century or the invention of plastic. Are we not stuck here? Let’s now discuss the other side of the story—that dams cannot be blamed for floods. Then, the question arises: What exactly is causing an increasing number of river floods? Researchers, scientists and environmentalists, after thorough investigation, have noted there are three main reasons for the same:
First, water in reservoirs of dams, at times, is allowed to be filled to the brim, so that there is no shortage of water for electricity-generation. And when there is a sudden downpour—which is increasingly happening in this era of climate change—the gates are suddenly thrown open to save dams from destruction. This is what happened in Kerala, where of the more than 50 dams, gates of about 30 dams, including of the large Idukki Dam, were thrown open. It should be understood that water has to be released intermittently, and for this it is necessary that advanced warning about heavy rains is provided to dam managers by the meteorological department and other weather forecasting agencies.
Second, there is total disregard for the environment while carrying out infrastructure development or developing human habitat, alongside fragile river banks and basins. Here, it appears we are not taking sufficient measures to ensure that proper drainage system is kept intact—it includes maintenance of the system and regular de-silting, so that excess water can be easily stored and channelised all the time. The recent deadly floods in Uttarakhand and J&K can be attributed to these reasons.
Third, unregulated and rampant mining—which destroys forests and leads to soil erosion—aggravates the occurrence of river floods. In Kerala, landslides, degraded soil and debris deposits due to quarrying and sand mining contributed substantially to the damage due to floods. Here, it must be mentioned that a report—by a committee headed by ecologist Madhav Gadgil in 2011—had warned that mining and hydropower dams are threatening the ecologically-sensitive areas of the Western Ghats because of reckless resource extraction, but, alas, the report was junked. Also, a government-backed report in June 2018, asserting that Kerala was at the risk of a big disaster, was not heeded to. Many districts in Maharashtra, Goa and Karnataka, falling in the Western Ghats region, are other cases in point that have been badly affected in not too distant past by river floods. The above findings suggest that it is not dams, as such, but there are other reasons, as discussed, that are causing devastating floods. In view of this, measures need to be taken on a war-footing by central and state governments so that disaster due to floods can be sufficiently reduced:
Streamline and strengthen weather forecasting system about occurrence of heavy, long-duration rainfall (including cyclones and other types of storms or tsunami) in this age of climate change, when sudden, extreme and variable weather conditions are the ‘new normal’;
Take into account the fragile ecology of various regions, states, towns while carrying out construction and mining activities, and pay heed to the advice of researchers in this respect;
Manage water reservoirs of dams efficiently, relating to usage of water for various purposes. To conclude, there is a need for a ‘national-level flood-control authority’ that takes care of all matters regarding flooding. This has not been done so far, though the Rashtriya Barh Ayog (National Flood Commission) was constituted 42 years ago, in 1976, by the government of India. So, let us not damn the dam.