Relating to rivers

While dams are often promoted as the environmentally-friendly solution to electricity and water shortages, the UN`s panel on biodiversity has released a damning criticism of the practice of building dams and reservoirs on rivers. The study captures the severity of the impact of man-made constructions along major rivers. Based on satellite data, an international team looked at 12 million kilometres of rivers worldwide in the first global assessment of the human impact on our planet’s freshwater supply. The report found that almost two in three of the Earth’s longest rivers have dams or reservoirs built on them. Out of 91 rivers longer than 1,000 kilometres, only 21 retain a direct connection to the oceans, while just over a third of the world’s 242 longest rivers retain a free-flow. Most of the remain free-flowing rivers are located in remote parts of the Arctic and the Amazon and Congo basins.

While building dams has become the most natural thing to do, experts have warned that the practice is having a big impact on Earth’s biodiversity. Dams and reservoirs damage import ecosystems. The mode of economic development dominant in the world purely sees rivers as resources for the consumption of man, but the long-term consequences of such are often underestimated. A World Bank report into Pakistan’s water ecosystem in 2005 warned that the country faces major flooding if it does not desilt its rivers. The prediction came true in 2010 when billions worth of economic activity were lost in major floods. The impact of floods has not lessened since, nor have any lessons been learnt. Over the last year, the government has been pursuing a crowd-funding effort to build more dams in the country. According to the UN report, over 50 percent of the world’s rivers are now showing severe degradation due to human activity.

Free-flowing rivers were once the lifeblood of human civilisation. The industrial revolution gave man the hubris that s/he could tame nature – without feeling the impact of such a move. Now, the impact of over a century of building dams en masse on free-flowing rivers is beginning to show its impact. One of the major impacts is the disruption of the flow of natural nutrients to replace those lost through agriculture. Moreover, dams restrict the amount of river-bourne species that complete their lifecycles. Hydropower projects in of themselves lessen the flow of sediment to river deltas, which reduce their projection against sea level rises. The question is whether the UN biodiversity report will have any real impact on how we relate to rivers. Will humans stop building more dams? Will we find a way to return the major rivers to a state of free-flow? The chances of that are low.