The Feather River West Levee (FRWL) project is the largest levee design and construction project in California, with a total project length of 35 miles of levees in a diverse geologic environment. AECOM served the Sutter Butte Flood Control Agency as the Geotechnical Engineer of Record, responsible for all geotechnical investigations, analyses, and design work, from the Pre-Design Formulation Report through final design.
The FRWL has a long history of significant distress, including a levee break in 1955 that damaged/destroyed over 6,000 homes. During high-water events in 1997, numerous sections of the levee experienced significant under-seepage, through-seepage, and erosion problems. The USACE also identified the FRWL as a Category 2 levee, indicating a substantial risk and consequence of failure.
AECOM reviewed existing data on past performance, geomorphology, subsurface conditions, geophysics, topography and bathymetry, and developed a targeted design-level investigation program to develop remedial alternatives. This work characterized and identified under-seepage as the critical failure mechanism for the majority of the system. During design, AECOM was directly involved in the evaluation and selection of borrow sites, which ended up being a pivotal part of the project due to the lack of suitable borrow material in the immediate project vicinity. AECOM provided full-time supervision during construction and was heavily involved in reviewing contractor’s submittals and responding to requests for information.
Using the Cloud as a data storage platform throughout the project improved information sharing and enabled the office design team to review field logs in real time.
Awards
- ASCE Sacramento Section , 2015 Flood Management Project of the Year