Dam Trends Globally

Mega-Dams: Centuries’ Old Technology on the Way Out

Mega hydro-dams are an impractical, illogical, and outdated technology. In 2000, the World Commission on Dams, an entity established in 1998 by the World Bank and the IUCN to review large dam projects all over the world, concluded that on average dam projects face cost-overruns of 56%, that promoters systematically exaggerate expected benefits, and that 55% of the analysed dams generated less power than projected. Similarly, a 2014 study out of Oxford University finds that, “even before accounting for negative impacts on human society and environment, the actual construction costs of large dams are too high to yield a positive return.”

Trends in the US towards decommissioning dams have experienced resounding success.  In 2014, 72 dams were removed, restoring more than 730 miles of streams for the benefit of fish, wildlife, and people. Within the last few years Vietnam has cancelled construction of over 30 dams. China was forced to cancel construction of a dam on the Jinsha river that would have displaced up to 100,000 people.

Read about Thayer Scudder, the world’s leading expert on the impact of dams and relocation, and how he decided that large dams aren’t worth the cost in The New York TimesCheck out a map of decomissioned dams in the US here.