Chinook salmon come home to Elwha River

 

Five months ago contractors ripped down the final remnants of the Elwha Dam, which along with its upstream counterpart, Glines Canyon Dam, has for a century been blocking the paths of salmon up the Elwha River, which winds through Washington State’s Olympic National Park and empties into the Pacific at the Strait of Juan de Fuca.

Before the dams were built, without fish ladders, in 1913 and 1927 respectively, wild chinook salmon, some as large as 100-pounds, had access to 70 miles of the Elwha and its tributaries. The dams cut their spawning ground to the first five miles of river from the mouth, which drastically curbed spawning rates. Before the dams were installed, some 390,000 fish spawned in the river annually. This number dropped to just 3,000 while the dams were in effect.

When complete, the unprecedented deconstruction of these dams will open the salmon’s range to that enjoyed by their early ancestors. But it also comes with a biological price tag since vast quantities of sediment have built up in the dams over the years. Combined, the termination of the dams will release about 24 million cubic yards of sediment - enough to pack into a football stadium two miles high. And while some of the coarser components, such as gravel, will sink to the riverbed, providing essential habitat for salmon to spawn, the finer material – silts and clays – that turn the river water brown poses a threat to the salmon’s survival, explains Brian Winter, Elwha project manager for Olympic National Park.

The time the sediment will take to flush out to sea could vary between three and five years, depending on rainfall and stream flow in the coming winters, he says. Research into how the release will affect marine life is ongoing (as seen in this video of USGS researchers scouting the seafloor in scuba gear).

To shield fish from the impacts of the unleashed sediment, Barnard Construction, the Montana company contracted to pull down the dams (at a cost of $26.9 million) is working around a set of “fish windows” – periods where deconstruction does not lower dam height and allow sediment to escape. Until the current window ends in mid-September, work is being done to dismantle a 115-foot intake tower at Glines Canyon Dam.

Biologists from the state and Lower Elwha Klallam tribe are also collecting fish, including coho salmon and wild steelhead, from the lower river regions to rear in hatcheries and then releasing them upstream of the dam sites, before the next stage of deconstruction takes place, says Winter. To help protect the new fish populations there is a five-year moratorium on fishing in the river, which started last year.

A bunch of sediment waits behind the walls of the diminishing Glines Canyon Dam, and it will be some time before the river has stabilized, but chinook salmon have already started exploring parts of the river that were previously off limits and have been spotted close to the remains of the Glines Canyon Dam 12.5 miles upstream from the river mouth. Juvenile Chinook salmon were also seen at the park’s boundary when biologists were doing a snorkel survey, reports Peninsula Daily News.

These early visitors offer promise for how future generations of wild fish will repopulate the river during spawning season, but it will be some time -- as long as 28 years based on current estimates -- before numbers return to levels seen before the existence of the dams.

Brendon Bosworth is a High Country News intern.

Image: Site where Elwha Dam used to stand, courtesy National Park Service

 

High Country News Classifieds
  • COMMUNITY OUTREACH MANAGER
    High Country News (HCN) is looking for a Community Outreach Manager to reach and forge new relationships with individuals and groups who represent communities historically...
  • NEW BOOK:
    True Wildlife Tales From Boy to Man. Finding my voice to save wildlife in the Apache spirit. 365+ vivid colorful pictures. Buy on Amazon/John Wachholz
  • CHIEF OPERATIONS OFFICER
    with Rural Community Assistance Corporation. Apply here: https://www.marcumllp.com/executive-search/chief-operations-officer-rcac
  • CLIMATE JUSTICE FELLOW
    High Country News, an award-winning magazine covering the communities and environment of the Western United States, seeks applicants for a climate justice fellowship. The fellowship...
  • EXECUTIVE DIRECTOR
    The Wild Rockies Field Institute is seeking a visionary Executive Director to lead the organization in Missoula, Montana. Individuals with a proven track record in...
  • LAND AND WATER CONSERVATION DIRECTOR
    The Land and Water Conservation Director is a full-time salaried position with the Mountain Area Land Trust in Evergreen, CO. The successful candidate will have...
  • ARIZONA PROGRAM MANAGER
    National Parks Conservation Association (NPCA), the nation's oldest and largest national parks nonprofit advocacy organization seeks an Arizona Program Manager. The Arizona Program Manager works...
  • CROWN OF THE CONTINENT COMMUNITY CONSERVATION SPECIALIST
    THE WILDERNESS SOCIETY is seeking a Community Conservation Specialist, for the Crown of the Continent DEPARTMENT: Conservation CLASSIFICATION: Grade 6 Specialist/Representative (Low of $54K) REPORTS...
  • ASSISTANT FARM DIRECTOR
    About The Organization Building community through fresh vegetables is at the heart of the Sisters-based non-profit, Seed to Table Oregon. Based on a four-acre diversified...
  • CARPENTER WANTED
    CARPENTER WANTED. Come to Ketchikan and check out the Rainforest on the coast, Hike the shorelines, hug the big trees, watch deer in the muskeg...
  • DYNAMIC EXECUTIVE DIRECTOR
    VARD is seeking an Executive Director to lead a small legal & planning staff dedicated to the health and sustainability of Teton Valley Idaho and...
  • WATER PROJECT MANAGER, UPPER SAN PEDRO (ARIZONA)
    Based in Tucson or Sierra Vista, AZ., the Upper San Pedro Project Manager develops, manages, and advances freshwater conservation programs, plans, and methods focusing on...
  • CAMPAIGNS DIRECTOR
    Southeast Alaska Conservation is hiring. Visit https://www.seacc.org/about/hiring for info. 907-586-6942 [email protected]
  • FINANCE & GRANTS MANAGER
    The Blackfoot Challenge, located in Ovando, MT, seeks a self-motivated, detail-oriented individual to conduct bookkeeping, financial analysis and reporting, and grant oversight and management. Competitive...
  • WADE LAKE CABINS, CAMERON MT
    A once in a lifetime opportunity to live and run a business on the shore of one of the most beautiful lakes in SW Montana....
  • CONTRIBUTING EDITOR, BOOKS, CULTURE AND COMMENTARY (PART-TIME, CONTRACT)
    High Country News is seeking a Contributing Editor for Books, Culture and Commentary to assign and edit inquisitive, inspiring, and thought-provoking content for HCN in...
  • STATEWIDE COMMUNITY ORGANIZER
    ABOUT US Better Wyoming is a nonprofit, nonpartisan advocacy organization that educates, organizes, and mobilizes Wyoming residents on behalf of statewide change. Learn more at...
  • EXECUTIVE DIRECTOR
    TwispWorks is a 501(c)3 that promotes economic and cultural vitality in the mountainous Methow Valley, the eastern gateway to North Cascades National Park in Washington...
  • CLEAN ENERGY ADVOCATE OR DIRECTOR
    Location: Helena, Montana Type: Permanent, full time after 1-year probationary period. Reports to: Director of Policy and Legislative Affairs. Travel: Some overnight travel, both in-state...
  • PROFESSIONAL GIS SERVICES
    Custom Geospatial Solutions is available for all of your GIS needs. Affordable, flexible and accurate data visualization and analysis for any sized project.