Infiltration is limited and streams are highly susceptible to increased flows in southwest Portland. As the pressure increases to provide stormwater service (conveyance) to new and more intensive development in that area, the potential for increased hydromodification and water quality impacts to natural systems must be addressed.
W2r convened a group of subject matter experts from various City departments to develop an overarching strategy for watershed management, considering watershed-scale impacts from development. The strategy is focused on watersheds where stormwater infiltration alone is not a practical option due to steep slopes and fine soils. Our analyses and processes have helped the City prioritize spending for CIP planning and design efforts related to resource management, flood protection, monitoring, infrastructure resilience, and fish habitat. W2r paired information from multi-scale geospatial analyses of stream conditions, stream susceptibility, runoff patterns, stream power, development patterns, infiltration potential, and landslide risks with objectives and priorities from each City department. Work products included a "data-to-decision-making support matrix", which streamlined and made more useful the application of City monitoring efforts across its departments. It will also help in public outreach for stream protection and enhancement by identifying resilience options that are appropriate for specific geomorphic conditions.
Client
City of Portland Bureau of Environmental Services
Keywords
Recommendations for long-term monitoring and management, geomorphic assessment, policy development, capital improvement strategy for stormwater planning and hydromodification mitigation, urban stream resilience, infrastructure protection, MS4 permit monitoring and reporting
