Beaver Library

Beavers modify landscape morphology and hydrology, thereby creating habitat for
diverse species, enabling many ecological processes, and promoting climate change resiliency.
Beavers are now rebounding from near extirpation in North America and increasing beaver
populations can facilitate restoration goals given beavers’ roles as ecosystem engineers. This is
especially relevant in the Chehalis Basin in western Washington where beaver is a focal species in
the Aquatic Species Restoration Plan (ASRP) which aims to protect and restore critical aquatic
habitat. Although beaver can be valuable for restoration, they can also cause conflict with people by
damaging trees, flooding roads, etc. Given potential conflict and the role of beaver in restoration, we
surveyed landowner perceptions of beaver and collated data on the status of beaver in the Basin.
Our landowner survey provides information to begin assessing the Chehalis Basin community’s
understanding of and desires for beaver. Our study explicitly explored whether negative attitudes
towards beaver are positively correleated with an individual’s reported conflict with beaver.
Notably, we found that landowners experiencing conflict with beaver were more likley to agree
with lethal control of beaver and disagree with maintaining beaver-created habitat than
landowners not experiencing conflict. This survey’s results underscores how proactively
addressing human-beaver conflict in the Basin is crucial for avoiding increasing negative attitudes
towards beaver and beaver-related restoration. Our survey supports a need for outreach and
education on beaver conflict mitigation, particularly related to unwanted tree removal. We also
present trends data on recreational beaver trapping in the region and areas of reported beaver
conflict. Although robust beaver population data are lacking, we provide a compilation of known
beaver occurrences as a baseline for beaver activity, especially near restoration priorities. These
beaver status data, in conjunction with our landowner survey data, provide a comprehensive
picture of the state of beaver, beaver conflict, and beaver restoration in the Chehalis Basin. Our
findings can help guide restoration practitioners in the Chehalis Basin to best capitalize on beaver’s
habitat restoration potential while mitigating conflict now and into the future.

The two primary categories of beaver flow device solutions are pond levelers and culvert protection systems. The following combination of design fundamentals, best management practices, and site-specific criteria form a set of standards for making, installing, monitoring, and maintaining both culvert protection systems and pond levelers as beaver coexistence solutions. This document is intended to empower the landowners, organizations, municipalities, and wildlife professionals who are interested in finding solutions to ongoing conflicts between human infrastructure and beaver habitat while still retaining the beavers and their benefits. If you would like to install a pond leveler or culvert protection system, use these standards to guide your planning, design, installation, monitoring, and maintenance. If you don’t have the capacity to implement these BMPs, there are an increasing number of trained professionals who can assist in your project. To coordinate your installation with the applicable regulatory agencies, adhere to the state-specific, stepwise permitting process outlined in the document appendices

The purpose of this research was to assess whether there is an integrated approach to providing both turtle passage and beaver exclusion from drainage culverts on highways managed by the Ministry of Transportation.

This paper describes the social and ecological context for current beaver problems, how WFCDs function, gives installation and maintenance tips, and presents results of two surveys that assessed the effectiveness of WFCDs in alleviating beaver flooding problems in Connecticut and Massachusetts.

The Beaver Patrol (in Juneau, Alaska) developed a culvert protector that allows in-stream movement of larger fish, turtles, and other animals, while preventing beavers from placing larger wood into culverts.

A study of 482 flow devices by Beaver Solutions LLC in Massachusetts demonstrated that flow devices are the Best Management Practices for beaver dam flooding problems. Published by the Assoc. of MA Wetland Scientists, 2005.

This guidebook provides a practical synthesis of the best available science for using beaver to improve ecosystem functions. The overall goal is to provide an accessible, useful resource for those involved in using beaver to restore streams, floodplains, wetlands, and riparian ecosystems.

Describes alternatives to control undesirable flooding caused by beavers at wetland restoration projects

A review of “The Best Management Practices: Long Term Solutions to Beaver Dam Flooding 2010”, an instructional DVD for flow devices

WBUR article following Mike Callahan and Beaver Solutions installing a flow device in Millis, MA

A detailed description on how to install a flow device.

Snohomish pond leveler design.

Effects of pond levelers on salmon migration in beaver pond complexes.

An analysis from the Pacific Northwest on the relative costs and benefits of flow devices.

This review article traced the origin of non-lethal tools used to reduce beaver flooding as far back as the early 20th century.

The focus of this publication is to provide basic information on beaver ecology, damage, and management.

A comprehensive compilation of information related to beavers and their management with an emphasis on stream restoration.

A collection of self-help information and videos for landowners experiencing a beaver conflict.

This landmark 20 year study compares traditional lethal beaver control versus nonlethal management methods in the town of Billerica, MA. A total of 55 beaver conflict sites were studied. Sites that were managed with nonlethal control methods cost taxpayers significantly less than sites that were managed with beaver removal, and provided millions of dollars of ecological services to the town annually that would have been lost with beaver removal.

Educational article on building a Clemson Pond Leveler