Lecture Notes: Elwha River Restoration

Introduction to Restoration

• Restoration is challenging and often time-consuming.
• Key aspect of preparing for climate change is building resilience in communities, economies, and ecosystems.
• Successful restoration efforts highlight successful resilience building.

Elwha River: Importance and Background

• Located in Washington, spanning from the Olympic National Forest to the Pacific Ocean.
• Historically, the river flowed freely, supporting robust salmon populations.
• Two dams, constructed in 1913 and 1926, drastically altered the river.
  • Initially aimed to generate hydroelectric power.
  • Over time, proved inefficient and detrimental to salmon runs and the ecosystem.

Impact of Dams

• Significant reduction in salmon population; from hundreds of thousands to about 3,000 by the 1970s.
• Environmental degradation both upstream and downstream:
  • Loss of sediment, woody debris, gravels, and cobble.
  • Harmed salmon reproduction and affected nearshore environments.
  • Upstream species lost access to salmon and their ecological benefits.
• Dams blocked fish migration, affecting biodiversity.

Restoration Efforts

• Large collaborative group initiated efforts to remove dams.
• Included environmental groups, National Park, local businesses, and the Elwha tribe.
• Elwha River Ecosystem and Fisheries Restoration Act passed in 1992.
  • Allowed for federal purchase and decommissioning of dams.
  • Dams removed in 2011 and 2014.

Results of Restoration

• Immediate salmon recolonization upstream after dam removal:
  • All five types of Pacific salmon and trout species returned.
• Sediment release from the dam sites into the river:
  • About 21 million cubic meters of sediment.
  • 90% flushed downstream; 80-85% reached the shoreline.

Conclusion

• Elwha River restoration is a story of hope and success.
• Demonstrates the potential for effective ecological restoration when properly planned and executed.
• Serves as an inspiring model for future restoration projects nationally.