Dams Increasingly Considered Harmful, Dangerous

But when Canadian settler Thomas Aldwell harnessed the waters for electricity with two dams earlier this century, the salmon stocks dwindled. The fish were unable to get past the concrete blockades to travel upstream and spawn.

The Elwha peoples -- who continue to live on a small reservation at the mouth of the Elwha in the northwestern corner of the United States -- are hoping that the liberation of their river is not far off.

The project has its skeptics.

Ed Carter, president of the dam-building company, Harza Northeast of Utica, New York, is in charge of a study on dam removal by the American Society of Civil Engineers. He says that large dams like those on the Elwha -- those more than nine meters high -- are unlikely to be torn down.

Not that Carter rules out the removal of such dams altogether. "When you are making decisions (for purposes) that transcend economics, such as environmental reasons, you have to go to a political level," he says.

But Shawn Cantrell of Friends of the Earth (FOE) in Seattle says he is "cautiously optimistic" about the removal of the dams. In fact, he argues that there is sufficient political backing to get the money to take down the structures.

One report commissioned by the federal government says that removing the Elwha dams and restoring the river to a state where the salmon will return will cost as much as $113 million and take up to 20 years to accomplish.

Cantrell says that the restoration of the river, which was authorized through an Act of Congress in 1992, has the support of both the Republican and Democratic parties. Republican lawmaker John Kasich, head of the House of Representatives' Budget Committee, favors removal of the dams. But the project also has its opponents, including influential Washington state Senator Slade Gorton, a Republican.

Work on removing both dams would begin at about the same time. But the 31.5-meter downstream Elwha dam would be removed first because of structural flaws. All the water would be diverted before it is demolished. The 63-meter, upstream Glines Canyon dam would be removed section by section. The water level would be progressively lowered by cutting "notches" into the dam with diamond saws. Each section would then be demolished with small explosive charges.

Although work has yet to begin on demolishing these dams, environmental groups are already calling for others to be torn down. A coalition is fighting the removal of the Edwards dam on the Kennebec River in Maine, while others are calling for the destruction of the Savage Rapids dam on the Rogue River in Oregon.

The National Dams Inventory shows that 32 percent of the dams in the United States have a "high" or "significant" potential for problems.

The Teton dam in southern Idaho burst in June 1976 when it was being filled for the first time. The accident caused the death of a dozen lives and property damage of about a billion dollars.

Yet problems with dams have been more costly in other countries. An estimated 230,000 people perished when the Banqiao and Shimantan dams failed on a tributary of China's lower Yangtze River in Henan province in August 1975. Some 2,600 people were killed when Vaiont dam in the Italian Alps broke in 1963. And some 2,000 people died when the Macchu II dam in India failed in 1979.

Repair bills for dams that are in danger of bursting can be quite high. In the United States, between 300 and 400 of Wisconsin's 3,600 dams need repairs that will cost more than $100,000 over the next decade, according to Richard Knitter, who recently retired from the state's Department of Natural Resources.

U.S. environmentalists are citing cost and safety to bolster their arguments for dam removal and to challenge the relicensing of more than 300 hydropower dams that were awarded 50-year licenses in the country in the first half of the century.

Many of the dams the activists target were built for the economic benefits derived through hydro-power generation, while others were built for flood control or water supply.

Dams slow down a river, causing the water to become warmer. Contaminants and nutrient concentrations increase, causing toxic buildups of algae and spurring the growth of vegetation that may choke water bodies. Stagnant water also attracts disease-carrying mosquitoes and other insects.

All these changes can hurt native fish populations. A blocked river can quickly wipe out salmon runs unless fish "ladders" are provided or the fish are physically transported upstream.

Partly because of environmental pressure, U.S. government authorities have shelved most plans to build new dams. Only two major projects are still being debated: the Animas-LaPlata dam in southwestern Colorado and the Auburn dam in northern California. Both face tough battles from environmental groups before any construction begins.