Sarah Dyrdahl has spent much of her career planting trees along streambanks to promote clean drinking water, prevent erosion and protect the creatures living in and around the water.
But in the summer of 2017, she found herself high up in the Willamette National Forest, overseeing a radically different kind of river restoration project.
Here, skidders and excavators deposited fallen trees across the landscape and other heavy machinery worked to free the river from revetments and roads that confined it into an unnaturally narrow channel. This infrastructure once supported a now-defunct logging operation at this site. But for decades since, it remained locked in a state that neither provided quality habitat for fish and wildlife, nor served any useful human purpose.
“It looks like a dusty construction site, but that will change,” said Dyrdahl, executive director of the Middle Fork Willamette Watershed Council. “When you’re making habitat, the messier the better.”
Within weeks, the site would transform into a wide-open floodplain full of prime habitat for federally-protected Chinook salmon, bull trout and other species, and flood storage capacity and water quality improvements for the Willamette Basin’s human residents.
An altered landscape
For decades, the rare visitor to this high-elevation valley has known Staley Creek as a place where electric blue waters rush over grey boulders, cobble and bedrock in a narrow streambed, surrounded by a thickly forested 42-acre valley.
“It’s pretty,” Dyrdahl said, “but there isn’t much habitat value.”
Historically, Staley Creek would have spilled across the valley floor, weaving rivulets and pouring into shallow pools before meeting the Middle Fork Willamette River at the valley’s low end. Fallen trees and branches would have littered the floodplain, providing dam-building materials for beavers and cooling shade and food sources for juvenile fish, while fine gravel in the streambed made an ideal place for adult fish to deposit their eggs. The ground beneath the creek would have acted like a sponge, capturing excess water and releasing it back into the waterway during the hot summer months, when rain and snowmelt had dissipated.
Then came Western expansion. Settlers tamed the Willamette Basin’s wild rivers and logged the surrounding forests to make way for homes, farms and industry. But these actions came at the expense of native fish and wildlife.
Aerial photographs document how logging transformed this once-lazy section of Staley Creek into a steep, rushing chute. Seeking easier access to the valley’s trees, the Pope and Talbot Lumber Company built berms to confine the stream and drain the floodplain. Then came roads so logging trucks could access the timber. Staley Creek gathered speed in its newly narrowed path. Wood debris and gravel, crucial elements of healthy fish habitat, were either removed or flushed downstream as the rushing water carved deeper into the streambed.
“The river just blasted right through it all,” said Matt Helstab, Assistant District Fisheries Biologist for the U.S. Forest Service Middle Fork Ranger District.
By 2017, some sections of the floodplain were marooned a full 15 feet above the creek. Without human intervention, they would likely not see water again.
Staley’s cold, shaded waters should be prime habitat for the threatened bull trout and spring Chinook salmon. Instead, it had become useless to most aquatic species.
The consequences of the altered flow in this creek and many others like it rippled through the Willamette Basin. Cold water from these high-elevation streams eventually drains into the Willamette River, where it becomes a crucial cooling agent in waters that every summer reach lethal temperatures for native fish. Because Staley Creek wasn’t able to spread out across its floodplain during the wet season, less of its water soaked into the ground to replenish the underlying aquifer. So during the summer, less water was available to provide cooling relief for fish and humans downstream.
“Tributaries like Staley Creek are the arteries of a watershed,” said Dyrdahl. “You can’t have a healthy system without healthy arteries.”
A bold approach to restoration
After the U.S. Forest Service became the landowner via a land exchange in the late 1990s, the Staley Creek watershed became one of the Willamette National Forest’s restoration priorities.
Crews made an initial attempt in 2011, using helicopters to place logs in the stream. But because they had not addressed the creek’s unnatural velocity, some logjams were washed away. Those that remained provided minimal habitat benefits, unable on their own to reconnect Staley to its high and dry floodplain.
“The power in this river is just too great for those traditional approaches,” said Dyrdahl.
Six years later, when the Middle Fork Willamette Watershed Council, U.S. Forest Service and other partners teamed up to make another attempt at restoring Staley, they chose a dramatically different solution. Rather than addressing the symptoms of habitat degradation, they would attempt to restore the river processes that had been lost. The method, known as process-based restoration, represents a new and innovative way of approaching this work.
“Ten years ago, we would have put some wood in the channel without acknowledging that, at one time, there were several different channels,” said Johan Hogervorst, forest hydrologist for the Willamette National Forest. “Now we’re thinking, how can we get that complexity back?”
The crew was confident their method would work. But pulling it off would be a challenge. The project site is 25 miles from the nearest town, out of cell phone range and without so much as a cabin in sight. Rather than travel hours each day, some crew members chose to live on-site while work was underway.
Re-establishing the floodplain would require filling in the creekbed, so crews would have to temporarily reroute the water into a new channel. Before doing so, they would need to capture Staley Creek’s fish, newts and other aquatic animals and relocate them to a safe place downstream.
And because this new restoration method would so dramatically alter the look of Staley Creek, they’d also have to find a way to communicate with community members who might misinterpret the ongoing restoration as a scene of environmental destruction.
Their first step was to get the public involved. Crews took community members out on site visits, recruited them to assist in fish salvage, and hired local students to serve as summer interns on the project.
“We wanted this project to be about more than just restoration,” said Audrey Squires, restoration projects manager with the Middle Fork Willamette Watershed Council.
Then, the earth-moving began. Crews deconstructed the roads and berms that had pinned the river into place, using that material to raise the creek bed back up to the floodplain. They brought in about 450 whole trees – roots and all – to slow the water in its path and create snags, pools and shady hiding places for fish.
The hope is that the river will become a dynamic water body, its braided network of channels rearranging themselves each year as floods scour the streambed and deposit new debris.
“We’ll see change continually, and that’s the point,” Helstab said.
Already, Staley Creek has begun to show signs of success.
Wetland vegetation is resurging in response to the higher water table. Instead of blasting downstream, gravel has begun to deposit in the streambeds, creating spawning areas for salmon and trout. Bull trout and harlequin ducks, which had been absent from the stream during previous surveys, both turned up at the project site soon after work was complete. Beavers are also returning to make use of the new habitat.
The project’s early success earned it the 2018 Riparian Challenge Award from the American Fisheries Society Western Division. Time will tell how species respond long-term, but project managers expect a revival of Staley’s trout and salmon populations. They will continue monitoring the site for years to come, watching the changes unfold and looking for lessons that can be applied to future restoration projects.
Pleased with the initial results, project managers are eyeing other similarly degraded valley floodplains that could benefit from the same bold approach. They plan to launch a process-based restoration project this summer in nearby Coal Creek.
“If you can address the underlying problems from past land use practices and the ripple effect that causes,” Helstab said, “you can create better conditions for a whole host of species, not just fish.”