Auburn Ravine Force Main Replacement

Lookout Slough 2


CA Dept. of Water Resources
Ecosystem Investment Partners, Inc.


Geotechnical Design
Materials Testing
Construction Inspection


Solano County, CA


2018 – 2023


This project will create over 3,000 acres of habitat for Delta Smelt, Salmonids, Splittail, and other wildlife as well as flood benefits to the Yolo Bypass. The project includes a flood control levee along the north and east boundaries of the new habitat zone.  Further, the project will breach the existing flood control levee to subject the area to tidal inundation. Levee design complies with USACE and State of California Department of Water Resources (DWR) criteria for flood control levees.  This includes subsurface exploration, laboratory testing, and geotechnical analysis.

Subsurface exploration: Blackburn performed 43 exploratory borings, 5 cone penetrometer tests along the levee alignment, and 47 test pits within the proposed borrow source area.

Laboratory Testing: Blackburn performed permeability, consolidation, strength (CU, UU, DS), organic matter and classification tests of the foundation soil and proposed embankment soils.

Geotechnical Analyses: Blackburn developed 4 cross-sections based on our experience, existing information, and levee geometry. We developed seepage and slope stability criteria from USACE guidance documents and evaluated each cross section at a DWSE equal to the 1957 WSE + 1 foot. Blackburn estimated settlement under the proposed setback levee and seismic analysis, including liquefaction potential.

We recently completed the 100% design Geotechnical Basis of Design, Data, and Borrow Reports. Blackburn has consistently met deliverable schedules and budgets.

Geo-environmental: Blackburn reviewed the project Phase I ESA and conducted a Phase II ESA to define impacts from pesticide usage, chemical/paint storage, and above ground fuel tanks. Blackburn also completed an interior surface PCB and mercury assessment of 7-miles of abandoned natural gas pipelines present throughout the site.