Large-Scale Bank Stabilization on the Snake River

(Baker County, OR)  Landau Associates conducted an investigation of the causes of erosion along the banks of an impounded portion of the Snake River located in eastern Oregon. We conducted natural resources and geotechnical investigations and contributed to the development of a report that summarizes the likely causes of erosion, presents alternative design concepts that could be used to stabilize the shoreline, offers opinion of costs for each design concept, outlines the permits each alternative would require, and provides recommendations for moving forward. Investigations included visual inspections of the eroding bank and assessments of soils and shoreline habitat conditions.

Natural resources services included conducting an onsite assessment of shoreline riparian areas and the development of alternatives for erosion control using soft bioengineering techniques. Geotechnical services included general mapping of exposed strata in failed portions of the bank; general characterization of the geometry of the bank and shoreline material composition; an assessment of the potential causes of slope failure and potential scour mechanisms; and development of preliminary geotechnical recommendations for three alternative shoreline stabilization approaches.

Alternative solutions for erosion control using both hard armoring techniques and/or a combination of both hard and soft engineering were presented in a technical memorandum.