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 projects’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. Ample time will be allowed for questions from attendees.

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

President, JWF Consulting, LLC

John W. France, PE, D.GE, D.WRE is a registered professional engineer providing consulting services through JWF Consulting LLC. He received BS and MS degrees in civil engineering from Cornell University. John has more than 40 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, John 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 engaged by the Montana Dam Safety office to prepare a technical note on chimney filter design for posting on the State’s website, and he has been an instructor for ASDSO’s seepage analysis course; ASDSO workshops on seepage rehabilitation and internal erosion failure modes; and U.S. Army Corps of Engineers’ courses on seepage rehabilitation and embankment dam design. John has participated as facilitator or subject matter expert on numerous risk analyses of internal erosion issues, most recently serving as facilitator for an internal erosion risk analysis for Mosul Dam in Iraq. In 2017, he was the leader of the Independent Forensic Team charged with identifying the causes of the February 2017 Oroville Dam spillway incident.

OUTLINE

FINDINGS OF THE OROVILLE DAM SPILLWAY FORENSIC INVESTIGATION

 

  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

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Completion Certificate
2.00 PDH credits  |  Certificate available
2.00 PDH credits  |  Certificate available