Dams may have been the symbol of economic growth in a country's march towards being a ‘developed' nation, but not anymore. There has been a growing global movement against the impairing of our rivers’ health
Dams have always been a contentious issue from the environmental impact perspective, but in a first of its kind initiative, a non-profit organisation, International Rivers, has sought to reaffirm the same by successfully deploying technology to demonstrate the role dams have played in impairing the health of world’s rivers. International Rivers, in association with Google Earth technology, has developed an online database of nearly 6,000 dams across 50 of the world’s major river basins, ranking their ecological health according to indicators of river fragmentation, water quality and biodiversity.
The dams featured in the database comprise a small percentage of more than 50,000 large dams that clog the arteries of our planet and effectively illustrate the impact of dam building on notable rivers such as Mississippi, Yangtze, Danube, Amazon, Mekong, and other river basins by degrading their biodiversity and water quality. A look through this database is enough to make one realise what humans have done to their water lifelines.
The river basins fragmented by dams are commonly affected by a disrupted water flow. While the compromised sediment flow results in lower crop production, the reduced water quantity causes an increase in salinity which, coupled with decomposition of organic matter and leaching of mercury from the soil renders the water unfit for drinking and irrigation. The profound and irreversible environmental impact of dam building has been widespread.
According to estimates, nearly 60 per cent of the world’s major rivers have been fragmented by dams and diversions and over a million square kilometres, or just under one per cent the world’s most diverse wildlife habitats and fertile land surface, have been inundated by reservoirs worldwide. This has resulted in one-third of the world’s freshwater fish species to be extinct, endangered or vulnerable. Many shellfish, amphibians, plant and bird species that depend on freshwater habitats are also extinct or at risk.
India too has had its share of prolific dam-building with nearly 4,300 large dams already constructed, and thanks to World Bank funding, many more are in the pipeline. large dams in various parts of India are estimated to have submerged about 37,500 sq km and displaced millions of people, besides adversely affecting the environment. Harnessing hydro-electric power, building long irrigation canals, river bed sand mining and diverting water for industrial use have become the hallmark of exploiting a river in India. There is an urgent need to recognise and respect the rivers as a natural resource and not plunder them. Currently, the bulk of the aid and investment money for water and energy development in India is spent on building large hydropower generating plants and industrial scale irrigation projects. Apart from continuing the exploitative trend of rivers, this is not able to improve poor people’s access to modern energy services and safe water.
Hydropower projects are executed at tremendous financial and environmental cost and are not the most sustainable and affordable way to address the growing demand for electricity and water services in the country. The Government must regulate further construction of newer and larger projects and explore alternatives to hydropower, which are in the form of environmentally sustainable, small-scale, cost-effective and decentralised water and power systems that deliver to the poor. This will help avoid energy transmission and distribution losses that occur while feeding the central power grid.
The detrimental impact of dams on the rivers’ ecosystem is being scientifically chronicled and based on this dam-affected communities across the world are joining forces to take intrepid steps to counter the same. Countries such as the US are leading the initiative. In a landmark decision, the US Congress has set an example in environmental conservation by instructing the Government to oppose any financial or policy support to large dams. It may be noted that the US is the biggest financial contributor to World Bank and other international financial institutions. In addition the US Government has also sought strict scrutiny of World Bank lending to hydro-electric projects by an independent external agency. These initiatives are helping to pave the way for river restoration and rejuvenation.
Dams may have been the symbol of economic growth or an important milestone in a country’s march towards being a ‘developed’ nation, but not anymore. Over the last 20 years, a growing international movement has emerged to challenge destructive dams, promote sustainable and equitable alternatives and secure reparations for dam-affected people. This movement has forced the indefinite postponement or cancellation of numerous projects around the world. Hopefully, India is able to follow suit by observing the global trend.