Cooperative Fish and Wildlife Research Units Program:
Education, Research and Technical Assistance for Managing Our Natural Resources

In stream ecosystems, urbanization is associated with increased erosion and habitat homogenization. This habitat degradation often has biological consequences, such as decreased species richness. The main driver of these geomorphic changes is the high frequency of erosive flows that occur in urban streams as a result of stormwater runoff draining from impervious surfaces. Conventional stream restoration practices are costly, and projects are limited to small areas with easy access. A scalable, low-cost method of stream restoration is needed to address the widespread degradation occurring in urban streams. Large woody debris (LWD), which is typically abundant in natural streams and low in urban streams, can reduce water velocities, generate pool habitat, decrease erosion, and provide cover for aquatic organisms. In this study, we performed experimental LWD installations to assess the capacity of LWD restoration to decrease erosion and sediment transport and increase the availability of pool habitat. In May of 2022, eight log jams were installed in Cooper Creek, a headwater stream in Cincinnati, OH. The geomorphic effects of these installations were monitored using a before-after-control-impact study design in four 60-meter reaches, two treatment and two control. We found that these installations are able to rapidly increase pool habitat availability when jams remain stable, but there was little impact on sediment transport. In the first year following the installation, a majority of the LWD structures were mobilized and reconfigured by flow events, but the overall density of LWD within the study site remained high relative to initial conditions. Further investigation is needed to address the stability concerns in order to maximize desired outcomes and minimize the potential for wood-related damage to local infrastructure.