Beaver are native to the Pacific Northwest and inhabit a critical place in the region's aquatic ecosystem. They are important for water retention across the landscape and salmon habitat.
Beaver can also cause frustrating issues around road culverts, houses and planted landscapes. Fortunately, there are cost-effective, long-term solutions to most situations including road culverts, flood gates, beaver ponds, etc.
While these "flow devices" are relatively new to the Pacific Northwest, Beaver State Wildlife Solutions has trained with flow device the innovator Mike Callahan, of Beaver Solutions LLC in Massachusetts, who has resolved over 1000 beaver related conflicts since 1998.
These low-maintenance solutions to beaver conflicts have been embraced by highway departments, utility companies, private businesses and landowners, federal and state agencies, watershed councils, and environmental organizations.
Flexible Pond Leveler
Much like the bathtub drain that prevents water from filling past a set level, the flexible pond-leveler can be extremely effective in reducing flooding by restricting the level of a beaver pond. These devices essentially create a permanent leak in the beaver dam, through a caged intake pipe within the beaver pond. This solution is especially suited for situations where human infrastructure like houses, storm drains, or roads are threatened.
Trapezoidal culvert fencing is extremely effective in protecting road culverts from beaver damming activity. These devices create a structure for beaver to dam along that misdirects the beaver's damming efforts farther away and further the culvert. As the beaver move away, the biological cues to dam are diminished and beaver leave the culvert to flow without obstruction.
Pipe and Fence
This solution gives the beaver a surface to dam on near the culvert, through which a flexible pond leveler is installed that moves water into the unobstructed culvert. This device is perfect for narrow stream conditions, where a trapezoidal fence may not be possible, or in places where a small beaver pond is allowable near the road (trapezoidal fencing will drain the beaver pond completely). These devices are very successful, and low maintenance over time.
In parks, or private lands, sometimes the biggest issue with beaver is their tenancy to cut down trees. Effective tree protection is possible through a variety of methods, depending on the desired aesthetic, and the quantity of trees.
Lamprey Passage for Small Dams
Pacific Lamprey are an important native fish species in the Pacific Northwest. Like other returning anadromous fish, lamprey struggle with barriers to their upstream migration. While they can use their mouths to suction up and over natural barriers like water falls, concrete dams (even small irrigation diversions) are often impassable because they cannot suction over the right, 90° angle at the dam's crest.
We are in the process of designing and prototyping a solution that would insure the lamprey's ability to climb the surface of the structure and create a lamprey-passable curve at the top of the dam. Beaver State Wildlife Solutions is in the process of partnering with lamprey specialists and other stakeholders, to create a cost effective, long-term passage retrofit, that could be used on small, channel spanning concrete dams across the landscape. In conjunction with these retrofits, we are collaborating and prototyping designs for video monitoring of lamprey passage at these sites, which could prove an important tool in monitoring lamprey populations across a larger watershed or basin.