Estimating Dam Failure Life-Loss Consequences to Motorists, Recreationalists, and Pedestrians for Hazard Potential Classification of Dams

ABSTRACT ONLY - Determining the hazard potential classification of a dam is a critical component in the prioritization and administration of a dam inventory. The hazard potential classification of a dam categorizes the potential for adverse consequences in the event of failure or mis-operation. Adverse consequences generally include the probable loss of human life and the impacts to economic, cultural, environmental, and lifeline interests; dams are generally classified as low-hazard potential, significant-hazard potential, or high-hazard potential in accordance with the type and magnitude of the potential consequences. Of particular concern for assignment of a high-hazard potential classification is establishing if there will be probable loss of human life. However, estimating the probable loss of human life is particularly difficult when considering transient populations such as motorists, recreationalists, and pedestrians who may only temporarily occupy the area inundated by a potential dam failure flood. Under-estimation of potential life loss at roadways, recreational areas, and pedestrian routes may result in an inappropriately low hazard potential rating and under investment in dam safety activities at the dam, while over-estimation may divert resources away from other dams where they are needed more urgently. Therefore, the Bureau of Indian Affairs (BIA) Safety of Dams Program has completed a review of existing state-of-the-practice publications applicable to hazard potential classification of dams based on potential consequences for motorists, recreationalists, and pedestrians and developed a set of guiding principles and an analytical framework for estimating probable life loss at roadways, recreational areas, and pedestrian corridors. This presentation will summarize the results of the literature review and provide a detailed discussion of the framework developed by the BIA for determining the hazard potential classification of dams based on the potential consequences to motorists, recreationalists, and pedestrians. The framework provides a quantitative method for estimating transient population at risk (PAR) and probable life loss that may improve prioritization and administration of dams.