Impacts of Artificial Beaver Dams (ABDs) on Degraded Wet Meadow Habitat, Silvies Basin, Oregon

There is increasing evidence to suggest that the pervasive channel incision seen throughout the West is due, in part, to the removal of beaver (Castor canadensis) in 19th century. A new method of artificial beaver dam (ABD) design and construction has been used on the tributaries to the Silvies River, a basin draining the northern-most extent of the Great Basin in Eastern Oregon with extremely high historic beaver populations and a presently recovering population. Such dams locally raise stream beds and water tables, reconnecting incised channels to their former floodplains, increasing hydraulic diversity, and promoting the development of riparian vegetation.  

A coordinated effort between the USFS Pacific Northwest Research Station. Oregon State University, and the Silvies Valley Ranch is underway to better understand the evolving impacts of these structures on local hydrology, geomorphology, and ecology.  Cottonwood Creek, a second order tributary to the Silvies River, is being implemented with a high density of fine-resolution hydrologic instrumentation to directly measure changes to surface, ground, and soil water. Unique to this site is an intact beaver meadow, which will serve as a reference reach, and a deeply incised reach, which will remain un-treated to serve as a "control".