College of Earth, Ocean, and Atmospheric Sciences

By Nancy Steinberg

Posted October 1, 2019

Consider the beaver: Adorable, industrious, ingenious, so beloved in Oregon that we are proud to call ourselves the Beaver State. The race to trap them two centuries ago for their valuable pelts was central to the development of the Pacific Northwest and played a critical role in U.S. history. And of course, Oregon State University has a thing for beavers.

Sadly, Beaver Nation, our fuzzy mascot is not universally beloved. Between the fur trade and removal to combat dam-induced flooding, the beaver population is significantly reduced from historical numbers. Today, many landowners throughout the west consider them pests.

Now, groups interested in river restoration are trying to bring beavers, or their dams, back to certain Northwest landscapes. Beaver-related restoration, also known as BRR, is gaining traction as a method to restore deeply incised streams – those that chisel through the terrain, creating mini-canyons with steep banks.

BRR can mean plugging up streams with structures that mimic beaver dams, creating conditions under which beavers will return to the landscape and build dams themselves, or even relocating actual beavers to restoration sites. The hope is that these approaches will encourage the incised streams to rise behind dams, reconnecting them with their flood plains and restoring streamside meadow habitats that originally blanketed parts of the Northwest.

An interdisciplinary team of Oregon State faculty and students has been studying the successes and challenges of this approach. The team is trying to bring analytical eyes to a process that inflames passions, both pro- and anti-beaver.

For advocates of BRR, some so fervid that they have been called Beaver Believers, the “nature-healing-nature” aspect of this approach is tremendously attractive. And there are certainly examples of successful BRR projects. The Oregon State team has examined one on private land south of John Day, Oregon, called Silvies Valley Ranch. Property owner (and OSU alumnus) Scott Campbell built what he called artificial beaver dams made of rock and asked Gordon Grant, a fluvial geomorphologist with the College of Earth, Ocean, and Atmospheric Sciences and the U.S Forest Service, to take a look.

Indeed, Campbell’s approach raised the creek, reconnected it to its flood plain and brought riparian meadows back. “I’ve never seen anything as effective as what he’s done,” Grant says. “The magnitude of change is on the same order as the change that came with the incised streams, and his restoration was much cheaper than other methods.”

But, Grant warns, this approach might not be practical for other locations. Considerable uncertainty remains around the criteria for successful projects, and issues of appropriate governance, including which permits to procure and from whom, are as fuzzy as the beavers themselves.

Hannah Gosnell, a CEOAS professor who focuses on human dimensions of environmental issues, and recently graduated M.S. students, Rachael Davee and Zach Pike-Urlacher, are particularly interested in these governance structures and other human dimensions of BRR. “Some of the legal and institutional mechanisms in place to address other types of environmental restoration haven’t really kept up with the idea of using beavers to restore watersheds,” Gosnell says. “We’re asking: How do you create the right policies and laws and institutions to support this nature-based solution? A beaver that moves around is much more complicated than a log or other static structure you put in the river.”

With Gosnell’s support, Davee and Pike-Urlacher analyzed a number of BRR case studies, conducting extensive formal and informal interviews with stakeholders. Pike-Urlacher characterized emerging governance structures, finding that one of his study sites, the Upper Nehalem watershed, was more advanced than others with respect to adaptive governance on the BRR issue. “They are taking a more grassroots approach, rather than a top-down approach, using network formation and supporting ‘bridging organizations’ at multiple levels of government to address BRR issues,” he explains.

The Oregon State team is concerned that some of the BRR enthusiasm needs to be tempered with a greater understanding of the goals of each project and the criteria for success. Gosnell and Grant are co-authors on an upcoming paper that explores whether BRR generally achieves its goals. Grant’s recently graduated Ph.D. student, Caroline Nash, now at Boise State, is the lead author on the paper.

Nash points out that at every step of the flow chart of a BRR project, there are assumptions that must be met for success. Does the dam stay in place? If so, does it accumulate sediment at a meaningful rate? If it does both of those things, does the dam survive storms or flood events? “As you go down this list, the reliability of your outcome becomes a lot more site-dependent and dependent on success of the previous steps,” Nash says.

Nash notes that many successful BRR projects take a multifaceted approach to restoration, instituting land management changes along with BRR. “You may see an operational shift in how they’re managing ranching or agriculture, or where they’re building roads, or maybe they’re planting a bunch of new species in the landscape,” she notes. It can be hard to tease apart what factors led to landscape changes in these cases.

“What we really need to ask,” she says, “is how do we manage watersheds with beavers in them? How can we be good biotic neighbors, and how can beavers inspire us to adopt better land stewardship practices?”

If scientific data collection can be built into BRR regulatory requirements, Nash says, scientists, restoration practitioners and managers will build a better understanding of where this unique approach to watershed restoration will work best. Don’t be surprised if beavers—and Beavers—are once again making their mark on the western landscape.

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