Willamette River Bank Stability Study

ESA  Image

From the Cascades and the Oregon Coast Range flows the Willamette River. It flows swiftly through the upper Willamette Valley passing farmland, suburbs, and urban areas en route to the Columbia River. Riverbank stability is a key concern for the City of Eugene with many parks, public facilities, and homes along the river’s migration-prone channel.

ESA assessed bank stability and developed engineering strategies to protect the land, infrastructure, and private property along an eight-mile stretch of the Willamette River. The project reach was divided into 42 riverbank sections. For each section, ESA collected and incorporated 24 attributes into GIS, including locations of riffles, meander bends, thalweg, areas of high velocity, and observations of riverbank failures, riverbank and riparian vegetation, habitat, bank material, and soils. Historical channel sinuosity and channel migration were also analyzed.

After the study was completed, ESA worked with the City to develop protocols for bank protection alternatives for priority areas. Each area received detailed site analysis, including geomorphic, engineering, and geotechnical investigations. The alternatives identify opportunities to improve water quality and habitat, and point out key design and permitting challenges. We presented the findings and alternatives to City staff and later prepared construction and design cost estimates for the selected sites.

ESA collaborated with the City of Eugene to develop scientific strategies to protect the integrity and stability of this eight-mile stretch of the Willamette River.

Specialized Services

  • Biotechnical bank stabilization and grade control
  • Geological and soils investigations
  • Geomorphic assessments
  • Geomorphic mapping
  • Grade control and bank stabilization
  • Riparian restoration