Beavers restored a volcano-scarred river. Now it’s at risk again

More than 40 years after sediment from a volcanic eruption filled up a stretch of the North Fork Toutle River in the U.S. state of Washington, beavers are turning the smothered waterway into a thriving wetland. However, a planned infrastructure project now threatens to undo five years of restoration progress, reports contributor Isabel Gil for Mongabay. Following the 1980 eruption of Mount St. Helens, Mark and Dawn Smith, owners of the Eco Park Resort, watched as volcanic sediment accumulated over native vegetation and wildlife along the river. The degradation was exacerbated when the U.S. Army Corps of Engineers in 1989 built a sediment retention structure (SRS) to hold back sediment to protect shipping routes and downstream communities from flooding. The structure trapped volcanic material, creating a massive sediment plain on the Smiths’ property. In 2021, the Smith family began collaborating with natural resource experts from the Cowlitz Indian Tribe, the Cascade Tribe, and conservation groups to reintroduce beavers (Castor canadensis) to the area. Emily Fairfax, an assistant professor of geography at the University of Minnesota, told Mongabay that 58 beavers have been relocated to the resort in the last five years. Many of them were at risk of being euthanized after coming into conflict with humans in other areas. The relocated beavers have established a complex network of dams and what Smith described as “honeycomb” canals, deepening ponds and allowing native willows and alders to take root. Smith said he’s seen ducks and elk return to his property. Moreover, the restored wetland habitat now supports sensitive fish species, including Chinook salmon (Oncorhynchus tshawytscha) and rainbow trout (Oncorhynchus mykiss). While some beavers continue to live in the resort, others have even moved out to nearby land via connected waterways. “It is really amazing to see how their engineering activities are essentially helping regreen this volcanic wasteland,” Jonah Piovia-Scott, a biology professor at Washington State University, told Mongabay. The U.S. Army Corps of Engineers recently announced plans to further raise the SRS spillway crest by 10 feet (3 meters) to mitigate downstream flood risks. Mark Smith said raising the SRS would cause a fresh backlog of sediment that could bury the newly formed wetlands and fish habitats. Smith has filed a notice of intent to sue the Corps, advocating for nature-based solutions over human-made infrastructure. The prospect of losing the restored ecosystem is a heavy blow for the family. “I’m 67 now, and I’ve been here 35 years on this property and I’ve watched it die twice and I’m gonna have to watch it die again,” Smith told Mongabay. He said he remains committed to the project, asserting that if the habitat is destroyed, his family will be the first to help the beavers start anew. Read the full story by Isabel Gil here. Banner image: Beavers are restoring stretches of North Fork Toutle River in the U.S. state of Washington. Image by GrandTetonNPS via Wikimedia Commons (Public domain). Credits Topics