Findings of the Oroville Dam Spillway Forensic Investigation: On-Demand

At a height of 770 feet, Oroville Dam is the tallest dam in the United States. On February 7, 2017, a section of the concrete chute slab of the service spillway at Oroville Dam failed during spillway discharge. Several days later, as the California Department of Water Resources was evaluating and managing discharges through the damaged service spillway during a large rainfall event, the emergency spillway activated for the first time in the project’s history. The emergency spillway flow resulted in significant erosion of the hillside below the crest structure, leading to concern for the integrity of the emergency spillway and the evacuation of nearly 190,000 downstream residents. The Federal Energy Regulatory Commission mandated a forensic evaluation of the failure of the service spillway chute and the damage to emergency spillway. This webinar will present the findings of the six-person Independent Forensic Team, including discussions of physical factors, human / organization factors, and lessons to be learned from the incident.

John W. France, P.E., D.GE, D.WRE

President, JWF Consulting, LLC

Mr. John France is a registered professional engineer employed by AECOM as a Vice President and National Technology Leader for Dams. He received BS and MS degrees in civil engineering from Cornell University. Mr. France has 42 years of consulting engineering experience, during which time he has worked on hundreds of civil engineering projects. For the past 35 years his professional career has been focused on dam engineering and dam safety services. During his career, Mr. France has been involved in various capacities in evaluating and remediating seepage issues for earth dams. He has written numerous papers on the topic, and in 2012 he was an invited speaker at a FEMA workshop on filters and seepage remediation. He was also engaged by the Montana Dam Safety office to prepare a technical note on chimney filter design for posting on the State’s website. Together with Jennifer Williams he has presented workshops on internal erosion failure modes for ASDSO and the States of Colorado and Wyoming.




  1. Introduction
    1. Purpose of the Investigation
    2. Investigation Team
    3. Investigation Methodology
  2. Background Information
    1. Oroville Facility Description
    2. Regulatory Setting
      • i.     Federal Energy Regulatory Commission (FERC)
      • ii.     California Division of Safety of Dams (DSOD)
    3. Spillway Descriptions
      • i.     Service Spillway
      • ii.     Emergency Spillway
    4. Chronology of the February 2017 Incident
    5. Service Spillway Chute Design and Construction
    6. History of Service Spillway Chute Repairs
    7. History of Service Spillway Drain Flows
  3. Question Period #1
  4. The Physics of What Happened
    1. Service Spillway
    2. Emergency Spillway
  5. Question Period #2
  6. Why Was This Performance Unexpected
    1. History of Inspections and Regulatory Setting
    2. Geological Evaluations
    3. Chute Slab Repairs
    4. Potential Failure Mode Analyses (PFMAs)
    5. Activation of the Emergency Spillway
    6. Conclusions
  7. Lessons to be Learned


On- Demand Webinar
Open to view video.
Open to view video.
Post Survey
5 Questions
5 Questions Post Survey
Completion Quiz
10 Questions  |  3 attempts  |  6/10 points to pass
10 Questions  |  3 attempts  |  6/10 points to pass
Completion Certificate
2.00 PDH credits  |  Certificate available
2.00 PDH credits  |  Certificate available