Elwha Watershed Information Resource

There has been a significant decline in the number of fish in the Elwha River and the health of those fish since two dams were built on the river in the early 1900s. These dams have disconnected the upper and lower Elwha watershed for nearly a century, resulting in:

• Significant disruption of upstream salmon migration,

• Loss of 90 percent of salmon habitat, and

• Interruption of the downstream movement of both sediment and wood.

Coho Salmon. David Menke, U.S. Fish and Wildlife Service.

Current salmon populations (several of which are hatchery-dominated) are dramatically smaller than the estimated historical population--and two species of salmon are considered to be extinct in the Elwha River. The salmon populations that do persist below the dams are able to do so, in part, because channel incision has not been significant and floodplain habitats remain an important component of the Elwha River ecosystem.

Dam removal will (1) reconnect upstream habitats, increasing salmon carrying capacity and (2) allow the downstream movement of sediment and wood, which will improve aquatic habitats over the long term. Both of these large-scale changes will allow salmon populations to rebuild on a watershed-scale.

Learn more about the fish in the Elwha by clicking on the links below:

Fish Species: Many fished lived in the Elwha River historically, including all five Pacific salmon species.

History and Current Status: Historically, the Elwha River was home to several plentiful fish runs. Today, the fish populations are greatly reduced--but some species may begin to recover after the dams are removed.

Genetics Research: Before the dams are removed, DNA must be collected from the fish living in the Elwha River. This information will be used to help monitor the progress of the fish restoration efforts after the dams are removed.