Scope of Work
Project involved work along a levee segment in the Drainage District responsible for flood control adjacent to Portland International Airport. Central worked directly with the private client, Multnomah County Drainage District, and USACE Portland District Levee Safety Program Managers.
The evaluation included slope and retaining wall failure along a Columbia River levee system segment, due to failed culvert installation and drainage piping. The project involved the local restaurant’s parking lot located directly adjacent to the failed retaining wall area. Central assembled the standard USACE Drilling Program Plan per specification, included cross-sections of embankment and levee overbuild, and gained USACE permissions from the District to perform a geotechnical exploration.
Central led as Prime consultant, managing Civil design, survey, locates, and providing complete design for use in permitting and construction.
Features
- USACE Levee Safety Program oversight/coordination
- USACE Drilling Program Plan
- Existing levee encroachment violations (existing conditions)
- Section 408 review considerations
- Levee and overbuild cross-sections
- Geotechnical Exploration and Analysis
- Embankment/Slope Stability
- Levee maintenance/Section 408 recommendations
Results
The site involved Section 408 considerations versus allowable maintenance through the Drainage District. The overbuild area and depth to levee (2:1 projected line from the crest), were demonstrated, and geotechnical investigation occurred with the client, drainage district, and the work was completed under budget. During Design, a full set of plans and specifications for permitting and construction was led by Central as the Prime Consultant.
