Fish, Flow, and Habitat: Integrated Assessment of River Systems in Eastern Washington for Conservation and Restoration

The foundation of effective watershed restoration planning is a comprehensive consideration of the available data.  In order to better integrate and assess conservation and restoration potential of stream reaches in eastern Washington, we developed a scoring system for fish presence/absence and stock status, in-stream flow conditions, and habitat quality relative to specific fish life history stages.  The “fish” score was based on presence/absence of rearing, spawning/incubating, and migrating fish of a given stock, and was weighted by Federal (i.e., ESA) and State (i.e., SaSI) status.  The “flow” score was based on four factors, including overall stream size, the discrepancy between summer low and average flows, achievement of in-stream flow rules, and water right permit withdrawals as a percent of average flow.  The “habitat” score was based on physical attributes of the stream reach other than flow, namely off-channel condition, floodplain connectivity, riparian condition, passage condition, spawning suitability, and rearing suitability.  Eight Watershed Resource Inventory Areas (WRIAs) in eastern Washington were assessed using this three-dimension, multi-parameter paradigm and each stream reach was assigned a triplet value.  These values were then georeferenced to produce a GIS-based tool that allows quick visualization of complex data relevant to habitat restoration and fish conservation.  When web-enabled and made publically available this tool will allow diverse user groups, both governmental and private, to identify specific stream reaches in need of targeted restoration efforts, identify species-specific habitat use patterns, and “drill down” to evaluate additional questions that cannot be answered by any other single tool in existence.