Jake Place Spring Symposium Presentation - Danielle Reynolds

Many western river systems have become degraded or incised over time due to grazing, agriculture, impoundments, and extermination of beaver. Restoration efforts are looking to more natural solutions aimed at reconnecting streams to their original floodplain. Beavers were the original ecosystem engineers in Northwest America. They built dams, which held back water and sediment forcing stream channels in various directions, thus providing a mechanism for heterogeneity of fluvial processes and fish habitat. Restoration ecologists are looking to the beaver dam as a multifunctional tool aimed at reversing the anthropogenic effects of stream degradation. Baseline research was conducted at the Jake Place to provide important data and determine locations for beaver dam analogues. Important fluvial parameters such as pool to riffle ratios, historic floodplain areas and stream gradients were gathered for comparison after beaver dams were constructed. Five artificially installed beaver dam analogues were constructed in 2016 on the South Fork of the Crooked River. Dam porosity diminished in the weeks following installation, likely due to holes filling with aquatic vegetation, meaning fish passage may have to occur over or around the structures or during high flows. Following the 2017 spring flood event, two of the five beaver dam analogues had withstood the high flows and are functioning well, the other three dams did not withstand the event. Future work will include measuring sediment aggradation, success of riparian plantings, beaver activity, geomorphology, and fish passage