Oroville Dam Emergency Spillway Recovery

© Kiewit
© Kiewit
© Kiewit
© Kiewit

Ninyo & Moore provided upwards of 50 lab and field technicians and special inspectors for this major reconstruction project. Two Ninyo & Moore on-site laboratories were mobilized to facilitate adequate and timely testing of the construction materials. In 2020, the DWR was recognized by the American Society of Civil Engineers with the Outstanding Projects and Leaders (OPAL) Award for their efforts on the Oroville Spillways Reconstruction Project.

Project Highlights:

  • Special Inspection
  • Materials Testing
  • Emergency Reconstruction of Existing Spillway
  • Observation/Documentation of 7,000 Drilled Anchor Locations
  • Involved 1 Million Cubic Yards of Roller Compacted Concrete and 500,000 Cubic Yards of Structural Concrete
  • Two N&M Onsite Mobile Laboratories
  • 50 N&M Field and Laboratory Technicians/Special Inspectors

Ninyo & Moore provided special inspection and materials testing services for the Oroville Emergency Spillway Recovery project. During the winter rains of 2016 and 2017, the existing spillway had dangerously eroded and been compromised causing a significant hazard for the area residents. The California Department of Water Resources (DWR) contracted with Kiewit Construction to completely rebuild the spillway as well as ancillary roadways and parking areas around the dam between 2017 and 2020. Testing included laboratory and field sampling of the concrete, lab testing of the aggregates and various testing of miscellaneous structural backfill and placement of Roller Compacted Concrete. Special inspections were performed by Ninyo & Moore’s ICC inspectors during the construction of the structural concrete elements for the new spillway and asphalt testing for the roadways and parking areas.

Ninyo & Moore is excited to see the reconstructed spillway in action! We’re proud of our team’s efforts to support #constructionmaterials services for this critical emergency project. 

Project Details


State of California Department of Water Resources c/o Kiewit Infrastructure West


Oroville, California

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