Integrating regional and local monitoring data and assessment tools to evaluate habitat conditions and inform river restoration
Restoring degraded rivers requires initial assessment of the fluvial landscape to identify stressors and riverine features that can be enhanced. We present an inland Northwest USA case study in which we integrated local scale river habitat data collected using national monitoring tools with modelled regional water temperature and flow data. We compare local conditions in the Priest River in northern Idaho with those in other rivers (30 to 60 m wide) of the region. We summarized the variation in several dimensions of physical habitat among rivers using principal components analysis (PCA), and evaluated statistical associations among habitat metrics, flow, and mean August water temperature for the region. Results revealed high variability in aquatic conditions, but generally low instream cover, and low levels of large woody debris (LWD) across the region and within the Priest River. Habitat metrics including depth and LWD in Priest River sites differed significantly from other rivers grouped according to the level of anthropogenic disturbance. Elevation, mean summer areal flow, and drainage area explained 74 percent of the variability in modelled water temperature across the region. These approaches can be used to inform management and restoration and to develop aquatic monitoring plans at local and regional scales.