Elwha Watershed Information Resource

Removing the dams on the Elwha River and subsequently restoring the watershed is a major project. (In fact, this is one of the largest restoration projects in U.S. history.) Each step along the way, there are important questions to consider because restoration decisions will have significant environmental, cultural, and economic implications.

In the following sections, some of the restoration issues are discussed along with key management questions. These questions identify concerns, logistics, and areas of research that local, state, tribal, and federal entities are working to address before, during, and after removal of the Elwha River dams.

Sediment

Approximately 8 million cubic yards of sediment (including rocks and dirt) will be washed downriver within 5 years of the dam removal--just under half of the 17 million cubic yards of sediment that has built up behind the two dams over the last 90 years. In many ways, removing the dams will reconnect the upstream and downstream areas of the watershed.

Key management questions:

• How will primary and secondary productivity in the watershed be affected following the reconnection and the subsequent return of sediment and large woody debris to the lower river?

• How will sediment transport and deposition in the nearshore change (including amount of sediment reaching the nearshore, timing of inputs to the nearshore, movements in the nearshore, and pathways of sediment) over the short and long term?

• How will sediment inputs affect fish and wildlife productivity, behavior, distributions, and ecological interactions in areas near (riparian, wetlands, and mainstem) and far (uplands and headwater tributaries) from the river?

• What are the short- and long-term responses of fish, invertebrates, vegetation, water quality and habitat conditions within the estuary and nearshore to the restoration of sediment processes in the river?

• How will the local and tribal water supply (drinking, municipal, and wastewater) be affected?

For more information, see these pages:

Revegetation Overview
Nearshore Restoration
Environmental Impact Statements
Biological Opinions
Water

Revegetation

Over 600 acres of land will be available for revegetation (that is, replanting plants manually or letting nature re-establish the plants) once the dams are removed. (Currently, that land is covered by the two dams and Lakes Aldwell and Mills). The revegetation plan is to replant key areas with native plants such as Douglas fir.

Key management questions:

• What are the best methods to foster revegetation in these areas?

• What native plant species will be ecologically viable?

• What are the sources of these species?

• Will new vegetation be able to grow using the sediment from behind the dams?

• How can invasive species (that is, species that are not native to the area) be discouraged from colonizing newly exposed areas?

For more information, see these pages:

Revegetation Overview
Revegatation: Ongoing Research

Fish

Once the dams are removed, fish (such as salmon) that migrate from the ocean to spawn in fresh water will once again be able to travel up the Elwha River. Since the dams were built in the early 1900s, these anadromous fish have been restricted to the 4.9 miles of river below the Elwha Dam.

Key management questions:

• What are the best strategies to reintroduce anadromous fish runs to the upper Elwha River?

• How can these strategies be evaluated effectively?

• What sources of fish should be used for re-introductions?

• How will the return of marine-derived nutrients to upstream areas affect fish and wildlife productivity, behavior, distributions, and ecological interactions in areas near (riparian, wetlands, and mainstem) and far (uplands and headwater tributaries) from the river?

For more information, see these pages:

History and Status of Fish
Fish Species
Fish Management Plan
Hatchery
Environmental Impact Statements
Biological Opinions
Water

People

The restoration of the watershed will change the way the area has been for nearly a century, and many people who live and work around the watershed may be affected.

Key management questions:

• How will dam removal affect cultural activities of the Lower Elwha Klallam Tribe?

• How will dam removal affect commercial opportunities for local and regional organizations?

• What are the most effective ways to educate the general public, educators, and students about dam removal and restoration?

For more information, see these pages:

Salmon in the Elwha Culture
Resource Use