Strategic Implementation of Stream Restoration Actions Based on Alternative Species Views

Investments in stream restoration are typically intended to rebuild species under the Endangered Species Act (ESA) and to restore populations with strong cultural, social or economic value.  This presentation will focus on development of strategies for stream restoration using a species-habitat model, Ecosystem Diagnosis & Treatment (EDT) for Johnson Creek, a 37 km urban stream draining a 140 km² watershed mostly within the city of Portland, Oregon. The stream provides habitat for fall-run Chinook and coho salmon, and winter steelhead, all of which are listed under ESA.  Although abundant in the past, urbanization and other factors have largely extirpated these salmonids from Johnson Creek. The focal fish species also represent a co-evolved biological community expected under normative conditions. The City is investing in restoration of Johnson Creek to contribute to recovery of ESA listed salmon populations, increase quality of urban life and support infrastructural needs like flood control.  The analysis evaluated past, on-going and planned restoration to identify optimal strategies for restoration.  Specifically, we examined how multiple species views of restoration and synergistic effects of restoration projects can inform evaluation and planning of restoration. The analysis was based on characterization of stream conditions developed from standard stream habitat survey data collected at a reach scale.  The EDT model was used to interpret the stream condition from the perspective of the target species at reach, life stage and population scales. Diagnosis of the system identified limiting factors and restoration priorities for each species by reach.  Treatments were stream restoration actions modeled as changes to environmental data. The analysis provided a detailed restoration plan for the prioritization and phasing of restoration and demonstrated the contribution of Portland streams to ESA recovery.  Our analysis illustrates how each salmonid species provides a unique view of restoration based on life history, distribution and physiological requirements. The perspectives of multiple species were combined to create a community view of restoration effectiveness. Significant synergisms were found to occur between projects leading to the conclusion that strategic phasing affected the biological value of restoration investments.  Restoration projects considered in isolation often provided little or no benefit due to downstream constraints.  Consideration of suites of projects resulted in species benefits that exceeded the sum of benefits from individual projects. Consideration of project synergisms in restoration planning significantly improved the effectiveness of restoration programs.