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New policy on dammed rivers is 'go with the flow'
Monday, April 10, 2000 By Don Hopey, Post-Gazette Staff Writer
For much of the past two centuries, the United States has embraced a rivers-be-dammed policy of water management.
But now there's a growing trend to go with the flows as environmental, economic and safety considerations move policy from dam building to dam removal, said William L. Graf, former president of the Association of American Geographers, which held its annual convention in Pittsburgh last week.
"Five years ago, if you talked about dam removal, people would think you were nuts," Graf said. "Now it's a front-burner issue."
One hot example is the recent controversial recommendation by the U.S. Fish and Wildlife Service that four large dams on the Snake River in Washington be breached to restore the river's natural flow and allow migration of its endangered Pacific salmon stock.
Since 1990, more than 175 of the nation's dams -- 39 in Pennsylvania -- have been removed. While most of those have been small, unnecessary or dangerous to public safety, others have been breached because they degrade water quality, reduce biodiversity or impede fish migration.
"The same dams that caused river damage in the first place are now doorways toward restoration efforts," Graf told an audience of 300 at the David L. Lawrence Convention Center on Thursday. "We need to allow more living room for the nation's rivers."
A geology professor at Arizona State University, Graf said the first dams built in the United States were relatively small and usually connected to grist mills. Over the last century, however, technological advances allowed the United States to lead the world in dam building and greatly expand their size. More than 80,000 were installed.
"The golden era of dam building in the United States was from 1950 to 1980," Graf said. "After that it tailed off, partly because of environmental sensitivity, but mostly because all the good, big dam sites were taken."
Significant benefits accrued from the operation of the dams. Nationally, generating plants tied to dams produce 13 percent of electric power, 70 percent in the West. They also control flooding, provide navigation and transportation assistance, and are popular outdoor recreation venues.
But as dams grew in numbers and size, they began to significantly change the flow of water, sediments and nutrients in the nation's river systems. They chopped up the nation's rivers and streams into short, disconnected segments, fragmenting the watersheds and greatly reducing biological diversity.
Many fishes, mollusks and plants that thrived in free-slowing rivers and their natural pool-riffle-pool configurations couldn't survive in the long deep pools and reservoirs created by the dams.
"Given the way American rivers exist today, an examination of them is important," Graf said. "We must ask if this is the kind of river system we want to leave for future generations, and if not how it should be changed."
Of the 924 species on the federal Endangered Species List, half are there because they are threatened by current river management practices involving dams, Graf said.
So pervasive are dams and their effects that of the 3.2 million miles of rivers and streams in the United States, about 19 percent -- more than 600,000 miles -- have been covered over by the man-made lakes behind the dams. Another 79 percent of the nation's waterways are significantly altered by dam releases.
Only 2 percent, some 64,000 miles of waterways, remain in their natural, free-flowing condition.
"We're not exactly in the position of locking up America's river resources when we talk about preserving natural rivers," Graf said. "We must recognize that we have lost a system that was natural and are unlikely to restore the original conditions."
He expects that over the next century, national policy-makers will wrestle with balancing dams' social and economic benefits with their ecological impacts.
The evolving thinking on dams is reflected in the current budget of the world's biggest dam builders, the U.S. Army Corps of Engineers. Graf says one-third of the Corps' current spending plan is devoted to river restoration, a big increase over past budgets.
"Restoration of rivers has everything to do with political science, not biologic science," Graf said. "We can allow some change, some flooding, but the decision will be based on how much the local economy and government will permit."
Sixteen flood control dams have been built on the Allegheny and Monongahela rivers to reduce flooding, but Graf says he isn't suggesting that those be removed.
"Adjustments can be made, however. In addition to removal, dams can be changed physically or change their operating rules to have less of an effect on flowing rivers," he said. "All that costs money."
But so does flood control. Despite spending more than $30 billion on flood control projects, Graf says losses due to flooding in the United States are two to four times higher in comparative dollars than they were in 1900. And the public is paying twice because public money is used to pay federal flood plain insurance claims.
"Our multi-century legacy for future generations can and should be to establish physical integrity for rivers that are as natural as possible," Graf said, "thus insuring that as a system they are parts of the infrastructure for a vibrant national economy, continuing threads of our cultural heritage and a quality natural environment."
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