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"TEARING DOWN THE DAM IS THE EASY PART," says fisheries biologist Brian Winter, gesturing to the 108-ft.-tall, moss-streaked concrete wedge of the Elwha Dam, which plugs a forested river valley on Washington state's Olympic Peninsula. With a wave of his hand, Winter dismisses the three-year effort required to remove the spillway gates, the hoists, the crane, the enormous steel tubes that channel the river into the hydroelectric plant below, the plant itself and the reservoir that stretches up the valley, not to mention the 210-ft.-tall Glines Canyon Dam upriver and its reservoir. "That's essentially construction in reverse," he says. The hard part of the world's biggest dam removal project was the nearly three decades it took for multiple interests to agree to deconstruction, overcome bureaucratic inertia and find $184 million in funding.

The Elwha River Restoration Project, scheduled to begin in 2008, represents an extraordinary about-face in a nation that has been swiftly erecting dams since before the Declaration of Independence was signed. All told, more than 2.5 million dams--both publicly and privately owned--now block U.S. streams and rivers. More than a quarter have passed their 50-year average life expectancy; by 2020, that figure will reach 85 percent.

Once past the half-century mark, dams begin to degenerate: Concrete walls degrade, earthworks erode and seep, spillway gates rust and lose tensile strength, and sediment clogs reservoirs, reducing their capacity. In the worst-case scenario, an aging dam could fail, causing catastrophic flooding.

As maintenance and liability costs rise, economic returns drop. Many older dams are obsolete. Many others, including the Elwha and Glines Canyon dams, need upgrades such as fish passage structures that would cause the power they produce to soar above market prices.

Because of growing pressure from conservation groups, fishermen, tribal councils, and state and federal agencies, more dams are now being considered for removal in the United States than are being built. Nearly 200 have been torn down in the past six years. Most were small, low or involved a single stretch of waterway. The Elwha project, however, aims to restore an entire river system.

AS IT PLUNGES 4500 ft. from the snowfields of the Olympic Mountains to sea level west of Port Angeles, the Elwha River spans 45 miles. Fed by up to 240 in. of precipitation yearly, it was once phenomenally productive. Making 11 annual spawning runs were hundreds of thousands of fish: coho, pink, chum, sockeye and chinook salmon, plus steelhead, bull and cutthroat trout. The creation of Olympic National Park in 1938 preserved the upper watershed, but by then the Elwha and Glines Canyon dams, finished in 1913 and 1927, respectively, had blocked all but the lower 4.9 miles to upstream migration.

Winter, project manager for the National Park Service, lets his gaze drop from the spillway gates to the pools at the base of the Elwha Dam, which has been generating up to 14.8 megawatts of electricity for the local paper mill since it was first constructed. "When the light is right," he says, "you can see them down there--adult salmon, waiting to swim upriver, waiting for the dam to be gone." The Lower Elwha Klallam tribe, which has lived on the river for at least 2700 years, has objected to the dams since the early 1900s. Over the decades, conservation groups joined the protest. In 2000 the federal government purchased both dams for $29.5 million, setting in motion their removal under the oversight of the park service.

In the fall of 2008, Lake Mills, the 415-acre reservoir above the Glines Canyon Dam, will be lowered 50 ft. Then the dam's curving center arch, a section of concrete just 4 ft. wide at the top but 21 stories tall, will be cut out using diamond-wire saws. About a year later, the gates atop the Elwha Dam will be cranked open to drain 18 ft. from its reservoir, 267-acre Lake Aldwell. Crews will lower the stepped gravity dam--108 ft. tall and 100 ft. thick at its base--in 7- to 10-ft. increments. All traces of the dam will be removed by the fall of the third year.

Destroying both dams involves breaking up and recycling 35,000 cubic yards of concrete--more than half the amount used to construct the Empire State Building--along with hundreds of tons of metal. "We want to use as much of the material on site as possible," Winter says. Earth fill and crushed bedrock will be used to reshape the slopes around the dams to their original contours. The Elwha hydro plant and penstock tubes, with inside diameters that could comfortably accommodate an elephant, pose thornier problems. Some parts, such as the turbines, might be preserved as historic exhibits.

The two reservoirs must ultimately be drained of 48,600 acre-ft. of water--enough to flood Safeco Ballpark in Seattle, the home of the Mariners, to the height of a 130-story skyscraper. Then there is the reservoirs' sediment, 18 million cubic yards of the stuff, an amount so large that scientists have studied the debris flows from the explosion of Mount St. Helens to gauge how aquatic life will react to it washing downstream. Reservoir drawdowns will be carefully timed to manage turbidity.

By late 2011, both dams will be history, reservoirs drained and raw banks softened by sprouting trees. It will take three to five years for the river to flush out excess sediment, but the fish, Winter says, will likely reappear in a few months. It will be 30 years before the population is fully restored.

BEFORE THE ELWHA River Restoration Project can begin in earnest, the National Park Service must build two new water plants and intake structures for Port Angeles, which draws its water from the river. The Lower Elwha Klallam tribe must raise and lengthen the flood control levee for its reservation at the river's mouth. The tribe also must build a new sewage plant, as post-dam water tables will flood septic systems.

According to Robert Elofson, program director for tribal river restoration, both the wait and the work will be worth it. "We lived for the salmon," he says. "The river reflects who we are." Standing on the levee under a canopy of towering alder trees, he notes the rounded rocks packing the river bottom. "No gravel for the fish," he says. "And no sand for the beaches either. The ocean eats it all away and the river isn't bringing any down."

Since the dams were built, the swath of sandy beaches, where locals once earned money digging clams, has slowly disappeared. So has the river delta, which buffers the coastline from storm surges and supports emerging life from fish to crabs. The dams' removal will re-establish the cycle of nutrients from the river's headwaters to its mouth, sweeping sediment downstream, while opening 70 miles of the Elwha and its tributaries to the upstream migration of salmon. Winter calls the fish "packages of fertilizer with fins," because after spawning their carcasses supply the ecosystem with nitrogen and phosphorus.

Dam removal advocates will be watching the restoration of the Elwha River closely. Its success may provide the impetus to tear down other aging dams, including the four massive structures that block the lower Snake River in eastern Washington, and the 168-ft.-tall Matilija Dam on a tributary of Southern California's Ventura River. Elofson will be keeping an even closer watch on the free-flowing waters. Like Winter, he got involved in the Elwha project right out of college. Now 53, he hopes to hike upriver and catch a coho before he retires.

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