Sediment tells the story of a healing ecosystem

Lonesome Larry visits Elwha River

Larry at the Former Elwha Dam Site. Photo by Joanna Guild.

Part 2 of a two-part series. Click here to read Part 1.

By Steve Guild, IRU Summer Intern

Water at the mouth of the Elwha River is clouded with sediment that makes it impossible to see the riverbed. In this river, long plugged by two large dams, this is fantastic progress.

For over a century anadromous fish have been unable to return to their native headwaters. Cloudy water at the river’s mouth is a sign that the natural system is coming back to life.

To understand the impacts dam removal has on native salmon, I work up-river. This age old path has been followed by salmon entering ecosystems to spawn for millennia.

West of Port Angeles salmon enter the Elwha River from the Strait of Juan de Fuca. From its mouth the river stretches 40 miles up and into the Olympic Mountains. The Elwha River itself starts at a permanent snowfield known as the Elwha snow finger. The upper tributaries of the river originate in the heart of the Olympic Mountains, with the main stem draining the southeast slopes of Mount Olympus (Humes Glacier). Once completely freed later this year, there will be 75 miles of historic spawning habitat open to anadromous fishes for the first time in a century.

Elwha Dam, the lower of the two, blocked passage of fish attempting to travel upriver to spawn in the Elwha River’s headwaters since 1910. For the first time in more than a century, returning salmon are not trapped in a pool at the base of Elwha Dam. Returning fish now have access to 8.6 more miles of their historic habitat until they are stopped at the base of Glines Canyon Dam, which is 75 percent removed.

Sediment long trapped by the dams, however, is clogging systems meant to handle any amount of debris the Elwha could pass along. Unfortunately officials underestimated the amount of sediment delivered by the river in the early 1900s. The original estimated buildup behind the two Elwha dams was 15.3 million cubic yards, a number updated a few years ago to 24 million cubic yards. This past year the number was bumped even higher, to 36 million cubic yards. The amount of in-river debris is greater than the capacity of water treatment systems at Port Angeles to handle. Despite the latest and greatest in engineering technology we are only now beginning to understand the true negative impacts dams have inflicted on the local ecosystem.

Impacts of sediment in the water go beyond municipal water treatment issues. Sediment can also be fatal to salmon. Knowing this could be an issue for returning fish, the National Oceanic and Atmospheric Administration drafted the Elwha River Fish Restoration Plan, a blueprint for native salmon recovery to be implemented in tandem with dam removal. In accordance to the plan native fish stocks have been trapped and transported both above the Glines Canyon Dam and to specially designated hatcheries. These hatcheries will raise wild stocks to be released with their adipose fins intact to ensure the future of the river’s wild fish stock.

While the lower Elwha is cloudy with troublesome, though temporary, sediment, the upper river above Glines Canyon Dam is clear. To observe this I traveled around Glines Canyon Dam and returned to the river on a trail opened to the public at upper Lake Mills–the reservoir created by the dam. As I drank in my surroundings I was astonished by the stark contrast in the landscape. From gravel bars above the former lake I was able to see sediment that had built up behind Glines Canyon Dam. But looking into the river I could see clear glacial water tainted only by glacial sediment.

This dam removal is significant in that the Elwha was not freed by captains of industry, but in spite of them. It was the voice of a people begging for a healthy ecosystem that provided momentum to the movement that is bringing down unneeded and costly dams in every corner of the United States.

The Elwha dam removals are an illustration of what is possible and give me hope that the voice of the people will be heard again in the Columbia River Basin, where four dams on the lower Snake River continue to kill the majority of Idaho’s salmon. Removal of these monolithic impediments will give future anadromous fish a better chance at survival, will return fishing jobs to rural communities and will help restore balance to the ecosystem.

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