Safety Assurance Review – American Rivers Common Features

Challenges

Levee systems in the American River and Sacramento River watersheds are part of an overall flood management system in the Sacramento Valley known as the Sacramento River Flood Control Project.  This system includes 980 miles of levees and provides flood protection to over 2 million people in approximately 50 communities.  The U.S. Army Corps of Engineers – Sacramento District (USACE-SPK) previously identified seepage, stability, erosion, and overtopping concerns for various levee segments along the Sacramento River, American River, and various tributaries.

Solution

USACE-SPK is implementing the American Rivers Common Features Project that consists of constructing 13 miles of slurry cutoff walls to address seepage and stability problems, 21 miles of rock bank protection to address erosion issues, 6 miles of levee raises to reduce overtopping, and widening the existing Sacramento Weir and Bypass by 1,500 feet to reduce the water surface elevation in the Sacramento River.

RJH was retained by USACE-SPK to perform Safety Assurance Reviews (SARs) of the Sacramento Weir and Bypass widening and various segment of levee improvements along the Sacramento River east levee.  The SARs consist of independent, external peer reviews by technical experts to assess the acceptability of the design and construction activities to assure public health, safety, and welfare.

RJH’s SAR panel consisted of geotechnical, structural, hydrologic, and hydraulic engineering experts.  The RJH panel provided review comments to USACE-SPK, developed and evaluated a list of critical project components, considered the likelihood and consequences of failure, and prioritized each item relative to identified risk.