A Comparison of Risk and Resilience Interpretations of the Crisis at Oroville

The 2017 crisis at Lake Oroville has motivated the collection of an abundance of detailed information about the history and operation of the tallest dam in the United States, and made the case for studies seeking to improve the way dams and other critical infrastructure are operated and maintained. Existing investigative efforts rely on a risk‐management approach that reinforces the dam safety practices that are already in place. The risk-based approach places emphasis on the specific mechanisms that caused the main spillway to collapse. Consequently, it provides little insight into how the spillway collapse and subsequent response precipitated a massive, preventable evacuation and the worst‐case scenario: loss of crest control. A resilience‐based approach complements the risk‐based research that has already been completed to attain valuable understanding of such an event. Resilience research analyzes the interconnected decisions that steered the path of the Oroville dam and reservoir system toward crisis. This paper presents a decision timeline in that will inform resilience analysis. Three distinct themes emerge: 1) misalignment of technical nomenclature and design standards for the ungated spillway, 2) overconfidence in engineering designs and practices, and 3) conflicting pressure from diverse stakeholders. These factors contributed to unrealistic perceptions of dam capabilities and promoted decisions to forgo maintenance and design efforts that may have averted the crisis.