A Method for Estimating Potential Dam Failure Life Loss Consequences to Transient Populations

Estimating potential life loss consequences due to failure or mis-operation of a dam is a critical component in defining the risk associated with a facility. This estimation is necessary for conducting dam safety planning and prioritization. If potential life loss estimates are too low, a dam may not receive sufficient resources, which could lead to increased danger below the dam. Potential life loss estimates that are too high may result in overinvestment in the dam, which could then lead to increased danger below other dams within the inventory that may need the resources more urgently.
Several sources of uncertainty can lead to under- or overestimation. One significant source of uncertainty in these estimates is the presence of transient populations, such as motorists and pedestrians. Even though certain transient populations may only be present temporarily in an area at risk for a dam failure flood, the overall transient population may be relatively permanent and make up a significant portion of the population at risk (PAR) downstream of a dam, as individuals transition out of risk areas and others transition in to replace them.