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In 2014 the Elwha River returned to its free-flowing state with the removal of two hydroelectric dams. Together, these dams blocked 90% of the watershed to fish migration and sediment passage, and altered an ecosystem and cultural landscape for close to a century. After decades of lobbying by the Lower Elwha Klallam Tribe and allies, the United States Congress passed the Elwha River Ecosystem and Fisheries Restoration Act in 1992.
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Photo Credit: Brian Cluer

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Elwha Dam Removal Monitoring Data

In the following decades, NOAA and its many partners have collected a wide variety of data to research the impacts of dams and their removal throughout the Elwha ecosystem. To date, the removal of the Elwha Dams is the largest dam removal project in world history. With our research collaborators, we are examining how riverine, estuarine, and nearshore habitats are continuing to change after dam removal and what this means for the entire Elwha ecosystem.

NOAA scientists and partners have conducted monitoring and research on physical river-floodplain dynamics, water temperature, chemical changes in nutrients and stable isotopes, riverine benthic communities, juvenile salmonid diet, salmon recolonization and movement, genetics, and nearshore habitat and community studies. NOAA Fisheries is committed to sharing research data publically. The insights we gain are the heart of our science-based conservation and management. This website preserves this data legacy and provides public access to data sets to promote continued collaboration and learning from the Elwha Ecosystem Restoration Project for future monitoring and dam removal endeavors.

A regularly-updated Elwha bibliography is available at Zotero (courtesy of USGS)


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Researchers from the Northwest Fisheries Science Center work with the Lower Elwha Klallam Tribe, Olympic National Park, U.S. Geological Survey, and many other important partners. See our list of partners here.