Bend Bulletin: Beaver dam appears on Whychus Creek after restoration effort
A year after the completion of a major environmental restoration project on Whychus Creek — including conversion of cow pasture into a floodplain — beavers are returning to the area, a sign that efforts to “rewild” the creek are positively impacting native wildlife.
The beaver sightings occurred at Rimrock Ranch, around 10 miles north of Sisters. Deschutes Land Trust, a conservation nonprofit, purchased the ranch five years ago, intending to transform the land back to its original state and provide sanctuary for both fish and wildlife.
“We were excited to see a beaver or family of beavers built a dam this past fall in the newly restored area from 2024,” said Kris Knight, executive director of the Upper Deschutes Watershed Council, a nonprofit that spearheaded the restoration effort with Deschutes Land Trust.
“The beavers built a dam just around a year since restoration. This is exciting for us because it tells us that the restoration work we are doing is being used by wildlife like beavers,” Knight added.
Restored environment
In the mid-1900s, Whychus Creek’s floodplain was turned into a cattle pasture and the creek itself was straightened with help from a large berm. The effort severely degraded the environment here, making it inhospitable for both fish and wildlife.
Last year the watershed council completed a $1.5 million project to restore the floodplain. The work included planting native vegetation and laying cut trees in the floodplain to help divert water across the landscape.
Work has been done in stages and so far three out of six miles of Rimrock Ranch canyon has been restored.
“The style of restoration here is to take Whychus Creek out of a straightened and channelized alignment and allow Whychus Creek to flow again in multiple channels within the bottom of the valley and access the creek’s floodplain as it did historically,” said Knight.
Knight said the goal of the project has been to return Whychus Creek back a natural condition to support fish and wildlife populations.
“This means creating a more dynamic and natural system that will change from year to year like a natural stream system does from year to year through disturbances like high water events or floods.”
Beaver impact
Beavers also manipulate streamflow year to year through dam-building. Biologists say beavers do this to build a pond, which keeps them a safe distance from wolves, coyotes and other predators. Fish have evolved with beavers and can leap over their dams.
Beavers also recently set up shop upstream of Rimrock Canyon, in an area that the Deschutes Watershed Council restored in 2016. Knight says when beavers stake a claim on the creek and build dams their work supports fish populations.
“Having beaver occupy the site and build dams will add value to the restoration by slowing water down, expanding the area covered by water, and just creating additional habitat for fish and other aquatic life. Beavers are essentially picking up where we left off and adding to the restoration effort,” he said.
Steelhead numbers rise
Steelhead numbers are increasing in the Deschutes River, according to Portland General Electric, which co-owns the Pelton Round Butte Dam Complex with the Confederated Tribes of Warm Springs. During the current run, 732 steelhead have been released upstream, the most since the 1960s.
Whychus Creek is one of several tributaries undergoing restoration efforts to improve fish habitat; work some say may be contributing to the higher fish numbers.
“By completing these restoration projects, we are preparing areas for fish like steelhead to return where they can spawn and rear and use the new habitat as part of their natural life cycle,” said Knight. “That is a huge driver for this restoration work but the restoration efforts also benefit the broader Whychus Creek ecosystem for a variety of fish and wildlife.”
Allison Dobscha, a spokesperson for Portland General Electric, said fish biologists can’t say for certain if restoration efforts in Whychus Creek has increased fish numbers but adds that all ecological restoration work has a long term beneficial impact.
“We are encouraged by the significant improvements to habitat in this crucial tributary,” said Dobscha. “Improving habitat conditions in Whychus Creek could lead to more successful spawning in that area, producing future generations of salmon and steelhead.”
Historic beaver territory
Historically, beavers were common in the Deschutes Basin and their presence attracted fur traders. It was French traders who gave the Deschutes River its name. Increasing beaver numbers in the Deschutes Basin helps restore ecological function, biologists say.
“Stream restoration is about more than just fish. It is focussed on the restoration of ecological processes to benefit all organisms,” said Garry Sanders, a local aquatic biologist. “Beavers are considered ecosystem engineers whose actions can change and benefit multiple parts of the ecosystem.”
Sanders says beaver populations are improving in the Deschutes Basin but their numbers remain “much lower than they once were.” They once numbered in the tens of thousands in this area, he said, before trapping removed nearly all of them before the development of settlements.
“This has had lasting negative effects on our stream systems that we still see today,” said Sanders, whose past work includes 11 years as a restoration project manager with the Crooked River Watershed Council. “It has taken us 200 years to get where we are ecologically, it will take us 200 years at least to get to where we want to be.”
