Evaluating river restoration success using the California Rapid Assessment Method
Thesis (M.S.) Division of Science and Environmental Policy
Although there has been significant expenditure on stream restoration, no unified monitoring and assessment strategy for these projects exists. This study evaluates California's success at improving stream condition by assessing state-sponsored restoration projects and comparing them to high quality reference sites using the California Rapid Assessment Method (CRAM). CRAM evaluates stream condition using universal attributes that are each evaluated with specific metrics. Restoration sites were randomly selected from a database of restoration projects in California Regional Water Quality Control Board Region 3, the Central Coast. Reference sites were chosen to characterize the best attainable condition in the region. CRAM scores for restoration sites were significantly lower than for reference sites (p less than 0.001). Discriminant analysis showed that the overall hydrology attribute and specifically the channel stability metric were the most important variables in distinguishing between restoration and reference sites. When fish passage projects were removed from the analysis, the buffer metric was targeted in the discriminant analysis. Physical structure metrics had the largest difference in means between restoration and reference sites. Practitioners have been most successful in restoring landscape and biological aspects of streams. Future restoration efforts should provide adequate buffer and aim to restore fully functioning hydrology and physical attributes. This study shows how CRAM can be used to monitor and assess river restoration projects to improve future efforts. The next steps are to build a dataset of pre- and post-restoration CRAM assessments, and to gather support for standardized monitoring among restoration practitioners and funding agencies.