Survey of Beaver-related Restoration Practices in Rangeland Streams of the Western USA

Abstract

Poor condition of many streams and concerns about future droughts in the arid and semi-arid western USA have motivated novel restoration strategies aimed at accelerating recovery and increasing water resources. Translocation of beavers into formerly occupied habitats, restoration activities encouraging beaver recolonization, and instream structures mimicking the effects of beaver dams are restoration alternatives that have recently gained popularity because of their potential socioeconomic and ecological benefits. However, beaver dams and dam-like structures also harbor a history of social conflict. Hence, we identified a need to assess the use of beaver-related restoration projects in western rangelands to increase awareness and accountability, and identify gaps in scientific knowledge. We inventoried 97 projects implemented by 32 organizations, most in the last 10 years. We found that beaver-related stream restoration projects undertaken mostly involved the relocation of nuisance beavers. The most common goal was to store water, either with beaver dams or artificial structures. Beavers were often moved without regard to genetics, disease, or potential conflicts with nearby landowners. Few projects included post-implementation monitoring or planned for longer term issues, such as what happens when beavers abandon a site or when beaver dams or structures breach. Human dimensions were rarely considered and water rights and other issues were mostly unresolved or addressed through ad-hoc agreements. We conclude that the practice and implementation of beaver-related restoration has outpaced research on its efficacy and best practices. Further scientific research is necessary, especially research that informs the establishment of clear guidelines for best practices.

Sediment storage and shallow groundwater response to beaver dam analogues in the Colorado Front Range, USA

“…Beaver dam analogues (BDAs) are increasingly used as low‐tech, low‐cost solutions to restoring degraded streams across the American West (Pilliod et al, ; Pollock, Lewallen, Woodruff, Jordan, & Castro, ). Widespread stream incision and degradation in the mountain West were recorded post‐European settlement concurrent with beaver trapping and anthropogenic wood removal from streams (Naiman, Johnston, & Kelley, ; Polvi & Wohl, ).…”

Return flows from beaver ponds enhance floodplain-to-river metals exchange in alluvial mountain catchments

“…The recent phenomena of encouraging beaver recolonization and the installation of anthropogenic 'beaver dam analogues' in the context of stream restoration hopes to capitalize on expected net positive hydrogeological and ecosystem impacts (Lautz et al, 2018;Pilliod et al, 2018;Wohl et al, 2015). Natural and simulated dams can mitigate incised western channels by increasing floodplain connection and riparian vegetation regrowth, which in turn positively influences desirable recreational fish populations (Bouwes et al, 2016).…”

Low‐tech riparian and wet meadow restoration increases vegetation productivity and resilience across semiarid rangelands

“…In rangeland systems of the Intermountain West, benefits of proper grazing management have been reported (Oles et al ), but in general, implementation of low‐tech restoration has outpaced evaluations of efficacy (Pilliod et al ). One common fundamental outcome necessary for success of many restorations is enhanced soil water storage capacity to promote riparian and wetland vegetation (Hammersmark et al ).…”