Elwha Watershed Information Resource

The Elwha River Watershed contains a diverse collection of wildlife. (Since 83 percent of the watershed lies within the Olympic National Park boundary, the same species of animals are found in both places.) Species living in the watershed include over 300 birds (at least for part of the year), 64 terrestrial mammals, 14 amphibians, and 3 reptiles. Additionally, six species are endemic to (that is, only found in) the Olympic National Park: short-tailed weasel (Mustela erminea olympica), Olympic yellow-pine chipmunk (Tamias amoenus caurinus), Olympic marmot (Marmota Olympus), Mazama pocket gopher (Thomomys mazama melanops), Olympic snow mole (Scapanus townsendii olympicus), and Olympic torrent salamander (Rhyacotriton olympicus). See the list at the bottom of this page for further examples of wildlife in the Elwha watershed. Removing the dams on the Elwha River will be beneficial to most of the wildlife species in the watershed.

Impacts of Dam Removal

Most wildlife in the Elwha watershed will benefit from the dam removal, which will recover habitat and increase the flow of nutrients. Approximately 5.3 miles of riparian and river habitat was lost after the dams were constructed. (Riparian habitat encompasses the area between the land and the river, such as the river bank area.) Studies have found that close to 70 percent of the vertebrate wildlife species use riparian corridors. After dam removal, riparian areas that were once flooded by reservoirs will be recovered. An increase in nutrients will provide a nurturing environment for riparian vegetation which plays a key role in preventing stream bank erosion, filtering sediments and pollutants from the water, and providing habitat for fish, amphibians and small mammals.

Red-legged frog. Ryan Hagerty, U.S. Fish and Wildlife Service

Riparian restoration after dam removal will benefit both threatened fish and wildlife and federal species of concern. (Federal species of concern are not listed currently as threatened or endangered species, but they are being watched because of concerns regarding their status and threats to their existence.) Threatened species--such as the northern spotted owl (Strix occidentalis caurina), marbled murrelet (Brachyramphus marmoratus), bald eagle (Haliaeetus leucocephalus), bull trout (Salvelinus confluentus), and Chinook salmon (Oncorhynchus tshawytscha)--will all benefit from the additional habitat. Other Elwha inhabitants that are listed as federal species of concern will benefit too, including the Pacific lamprey (Lampetra tridentata), Northern red-legged frog (Rana aurora), Cascades frog (Rana cascadae), Van Dyke’s salamander (Phethdon vandykei), Northern Goshawk (Accipiter gentilis), Peregrine Falcon (Falco peregrinus), and Pacific fisher (Martes pennanti pacifica).

However, the dam removal will have some negative long- and short-term effects on wildlife as well. Species that use lake habitat--such as the lesser scaup (Aythya affinis) and trumpeter swan (Cygnus buccinator)--will be adversely affected by dam removal. Once the dams are removed, two major lake habitats (the reservoirs) will be lost permanently, and the species that use them will need to use nearby available habitat and wintering areas instead. Short-term impacts (such as construction noise) may adversely affect birds, mammals, and fish (e.g., bald eagle, northern spotted owl, marbled murrelet, and bull trout) on a temporary basis. Additionally, temporary habitat loss may occur due to increased turbidity during dam removal and adversely affect some animal species--but the net result will be a gain in habitat and food abundance over the long term (after the dams are removed). Animals that are temporarily displaced will recolonize the restored habitat areas after dam removal. On the whole, the negative wildlife impacts caused by the dam removal will be negated by the positive effects on the wildlife of the Elwha.

Species of the Elwha

The Elwha watershed is a rich and unique ecosystem that is inhabited by a variety of birds, mammals, amphibians, and reptiles. The following list provides examples of animal species in the watershed.

Birds

• Red-tailed hawk (Buteo jamaicensis)
• Osprey (Pandion haliaetus)
• Sharp-shinned hawk (Accipiter striatus) See Photo.
• Belted kingfisher (Ceryle alcyon) See Photo.
• Common merganser (Mergus merganser) See Photo.
• Mallard (Anas platyrhynchos) See Photo.

Mammals

• Roosevelt elk (Cervus canadensis roosevelti) See Photo.
• Black-tailed deer (O. hemionus columbianus) See Photo.
• Black bear (Ursus americanus) See Photo.
• Mountain lion (Puma concolor)
• Raccoon (Procyon lotor)
• Muskrat (Ondatra zibethicus)
• Mink (Mustela vison)
• River otter (Lontra canadensis) See Photo.
• Pine marten (Martes martes)
• Beaver (Castor canadensis) See Photo.

Amphibians

• Olympic torrent salamander (Rhyacotriton olympicus) See Photo.
• Rough-skinned newt (Taricha granulosa)
• Ensatina (Ensatina eschscholtzii)
• Northwestern salamander (Amybstoma gracile)
• Tailed frog (Ascaphus truei)
• Pacific tree frog (Pseudacris regilla)

Reptiles

• Northern alligator lizard (Elgaria coerulea)
• Common garter snake (Thamnophis sirtalis)
• Northwestern garter snake (Thamnophis ordinoides)

For a complete list of wildlife species in the Olympic Peninsula, please refer to the National Park Service site.

Reference

National Park Service. 1996. Elwha River Ecosystem Restoration, Draft Environmental Impact Statement. National Park Service, Olympic National Park, 600 East Park Avenue, Port Angeles, Washington, 98362.

Washington Department of Fish and Wildlife. 2007. Species of Concern.