DESCRIPTION: Columbia Stock Ranch (CSR) is a 936-acre site in the Lower Columbia River Estuary that was identified by the US Army Corps of Engineers (USACE) and BPA as a location for ecosystem restoration. The project included: construction of ±5,750 feet of setback levee with a maximum height of 23 feet, three breaches of the existing levee, two 4-span railroad bridges (120‑foot long), ±2,500 lineal feet of overflow channel, and a tide gate structure.
SERVICES: Foundation Engineering provided geotechnical analysis and design including: settlement, seepage, levee slope stability analysis, and back erosion piping following the USACE design manuals and guidelines. During the design phase, we provided additional exploration for a portion of the levee, scrape down areas, and two railroad bridges. We also provided driven pile foundation design for the two, 120-foot long railroad bridges. The additional investigation and railroad bridge design was provided without impacting the aggressive design schedule.
Characteristics of the material from the tidal channel excavations and the scrape down areas were evaluated for reuse in the levee construction and the levee was designed to make use of the existing materials to avoid importing material at a considerable cost savings.