Language
Country/Area
No result found
rom dams to ecosystems: What are the untold stories behind the Elwha River demolition project
The Elwha River, a 45-mile-long river on Washington State's Olympic Peninsula, was once blocked by dams that prevented native salmon from migrating. Today, the river is experiencing a resurgence as the largest dam removal in history allows ecosystem recovery to unfold.
History and ecological significance of the Elwha River
According to historical records, the name of the Elwha River first appeared on a map in 1846. The river flows from the Elwha Finger in the Olympic Mountains and eventually empties into the Strait of Juan de Fuca. Unlike other rivers blocked by dams, the Elwha River ecosystem is home to all five native Pacific salmon and four migratory trout species, with 400,000 adult salmon once successfully migrating to the river's 70 miles of habitat each year.
"Before the dams were removed, fewer than 4,000 salmon made it upstream, a number that is minuscule compared to before."
Behind the dam removal: long-term planning and huge investment
The removal of the Elwha River dams began in 2011 and took three years to complete, in one of the largest dam removal programs in U.S. history. The National Park Service's $325 million Elwha Ecosystem Restoration Project involves removing the 108-foot-tall Elwha Dam and the 210-foot-tall Glines Canyon Dam. This process is not just about dismantling the dam, but also an opportunity for ecological recovery.
“This project is not only about restoring fisheries, but also about allowing the ecosystem to recover and rebuild the natural habitats of plants and animals.”
Practical steps for ecological recovery
After the dam was removed, river sediment began to move toward the estuary, quickly recreating a 70-acre new estuary ecosystem. Modeling by the National Park Service predicts that as the river recovers, up to 392,000 fish could return to their original habitat, an expected re-creation of past ecology.
Elwha River Revived
As dams were removed, fast currents from heavy rains pushed sediment toward river mouths. By November 2014, 30% of the historical sediments had been successfully moved to the estuary, providing a good foundation for the formation of a new ecosystem. This is not only a change in data, but also a reconstruction of the ecology.
"A new ecosystem is taking shape, and the sound of flowing rivers is returning to this land."
Future Outlook
As the Elwha River ecosystem returns, the native plants here are also actively recovering, and tens of thousands of local plants are being planted in various places to promote ecological restoration. According to environmentalists' observations, the Elwha River will become a relatively pristine, less polluted ecological treasure in the future, providing a good habitat for local salmon.
This recovery plan also reminds us of the need to respect and protect these ecosystems while using natural resources. Human impact has had a long-lasting and profound impact on nature. So, with the success story of the Elwha River, can we find more ways to protect and restore nature in the future?
