Second Thoughts About Dams

ONCE HAILED AS THE SOLUTION to both water and electricity needs, dams are now seen in a less favorable light in many countries. “The assumption that the benefits outweigh the costs has become less certain,” says World Watch magazine. “Now that more than 45,000 large dams (over 15 meters [50 ft] high) have been built around the world, a growing body of research indicates that their costs may be higher than many ever imagined.” What are some of these costs?

A major cost is the degradation of 60 percent of the world’s waterways. World Watch notes: “Ecologically, rivers are under siege. They are being drained, diverted, polluted, and blocked at a rate that has degraded freshwater ecosystems worldwide. With more than half of the world’s rivers stopped up by at least one large dam . . . , dams have played a significant role in destabilizing riverine ecology. For example, at least one fifth of the world’s freshwater fish are now endangered or extinct.” Also affected are oceanic fish such as salmon, which can be blocked in their attempt to swim back upstream to spawn.

Even the generally held view that hydropower is pollution free is now in doubt. Why? Because rotting organic matter that ends up in reservoirs releases large amounts of greenhouse gases. There is also the social cost. Because of dams, 40 million to 80 million people have been displaced—more than the population of many countries—often from some of the world’s most fertile land.

The shift in attitude regarding the value of dams is spreading. For instance, the United States, which has a staggering total of 75,000 dams of all sizes peppering the country’s waterways, is now world leader in dam decommissioning and demolition. Even the World Bank has reduced funding for dam projects.

True, dams serve some useful purposes. But as with so many other endeavors, mankind’s dam-building spree has shown a lack of wisdom and foresight, confirming the prophet Jeremiah’s words that “it does not belong to man who is walking even to direct his step.”—Jeremiah 10:23.

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FOTO: MOURA