American Rivers

Damning the Dams

North America's native freshwater species—the fish, mussels, crayfish, frogs, snails and other animals that live in rivers and streams—are going extinct as fast as species that live in tropical rainforests.

And dams are mostly to blame. That's the message of a recent report, America's Most Endangered Rivers of 2000, released by the conservation group American Rivers. The report names rivers that face the most serious and immediate environmental threats.

Of the 13 rivers on the list, eight are threatened by dams. Washington's lower Snake River tops the list for the second year in a row because four dams operated by the Army Corps of Engineers have pushed salmon and steelhead to the brink of extinction. The dams have transformed the cool free-flowing river into a series of warm slackwater pools. Migrating fish succumb to predators and disease in the reservoirs and have trouble getting around the dams.

“We have blocked the flows, straightened the curves and hardened the banks of thousands of miles of waterways,” says Rebecca Wodder, president of American Rivers. “By changing the most fundamental qualities of rivers—their natural shapes and flows—we've made it difficult for them to support life.”

The Clinton administration will decide this year whether to include partial removal of the dams in its salmon recovery plan. Many believe dam removal would strike a devastating blow to the regional economy, but Oregon Governor John Kitzhaber recently spoke in favor of dam removal, saying, “My choice is to reject the guiltless complacency that has permitted this drift toward extinction and to simply do what needs to be done.”

The National Hydropower Association has criticized American Rivers' “most endangered” list for oversimplifying the issue. The industry group maintains that hydropower dams provide pollution-free, renewable energy, enhance biodiversity and improve habitat.

Is American Rivers' list of endangered rivers—with its focus on dams—a fair representation of the threats our nation's rivers face today? According to Anthony Ricciardi, a freshwater biologist at Canada's Dalhousie University, dams pose a major problem for the ecological health of rivers—but are not the only problem. “We also have to look at water quality, organic and chemical pollution and runoff from streets and yards,” he says. “The invasion of exotic species—the zebra mussel for example—is also something that has to be addressed.”

“If current trends persist, many more species will be lost over the next 100 years than during the past century,” adds Ricciardi. “That would be a loss not just for the United States, but for the world.”