The 45-mile (72km) long Elwha River in Washington State was historically one of the most productive salmon rivers in the Pacific Northwest. However, two dams built on the lower Elwha in the early 1900s set off dramatic changes: 90% of salmon habitat vanished, triggering ripple effects on wildlife, food webs, and habitat throughout the watershed.

In 1992, Congress mandated restoration of the river’s fisheries, and as a result, removal of the two dams started in September 2011.

These dams are the largest ones ever proposed for removal, and this will be the most complete restoration of a wild salmon river ever attempted. This project presents a remarkable opportunity to address questions concerning fundamental ecological topics involving nutrients and trophic webs, succession, aquatic and terrestrial habitats, and fluvial processes operating within a wild salmon watershed.

WEBCAMS and historical time series pictures of dam removal progress are located here! Latest images:

As the largest dam removal and fisheries restoration ever conducted this presents a unique opportunity for the study of ecosystem processes and ecosystem restoration. Predictions of the ecological effects of large dam removal are difficult. While nearly 450 dams have been removed in the United States, there are few published studies documenting post-dam removal effects.

Regionally, anadromous fish are essential to terrestrial ecosystems by providing an essential source of marine-derived nutrients, primarily nitrogen and phosphorous, to these relatively nutrient poor freshwaters. The combination of the shrinkage in habitat and reduction in nutrients in the Elwha River watershed due to damming is thought to have also caused declines in at least 22 species of terrestrial mammals and birds. After dam removal and salmonids colonize the habitats above the dams, marine derived nutrients are expected to increase and permeate throughout the aquatic and terrestrial habitats of the system. Other changes are also predicted to occur in nutrient chemistry dynamics and transport, sedimentation, physical characteristics, the fate of large woody debris, erosion, and exposure of formerly limnological soils. These will likely lead to other ecological changes in the watershed, affecting all trophic levels. Nowhere else is there such an opportunity to gain ecosystem-wide information.

For a more technical overview, please see Winter, B. D., and P. Crain. 2008. Making the case for ecosystem restoration by dam removal in the Elwha River, Washington. Northwest Science 82 (Special Issue):13-28.

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For more general information, a Google Earth mashup covering many of the social and educational aspects of project can be viewed with this kmz file.

General GIS data are available from the Elwha River Spatial Data Server.

A collection of Elwha Project research summaries was developed for middle school science classes prior to dam removal, and these summaries are linked with a Teacher's Guide and Lesson Plans.

Please see our Publications for even more info, particularly the 18 papers on the Elwha from the 2008 special issue of Northwest Science, or visit our information resource at www.elwhainfo.org. Other Elwha Project links include those by Olympic National Park, the Lower Elwha Klallam Tribe, Olympic Park Institute, USGS, and NOAA.

The Elwha Research Consortium (ERC) is a strategic partnership between governmental agencies, educational institutions, and community groups focused on understanding societal and ecological effects of dam removal and ecological restoration activities in the Elwha River watershed and nearshore environment in northwestern Washington State.

As a consortium, we wish to create and maintain a research and monitoring program over a long period to observe the full course of ecosystem responses. We also wish to create and maintain a wide-ranging education program linked to research on the Elwha, to fully distribute the knowledge gained to society, and for practical assistance in carrying out monitoring and research tasks.

Our mission is to facilitate a long-term program of research and education on the ecology, restoration, and management of the Elwha River watershed, from its headwaters to its nearshore ocean environments. We wish to improve understanding of the Elwha River watershed and the ecological and societal processes and effects of large-scale dam removal.

The ERC facilitates annual conferences for researchers and educators to share their work, network, and communicate with other like-minded individuals. Occasional workshops are held that disseminate research or education tools and techniques relevant to the Elwha project. Contact Jeff Duda at USGS for more information.