Dam-Induced Flooding: Scenarios, Consequences, and Difficult Choices for NRCS Dam Rehabilitation Projects

摘要

For many years, the dam safety community has prioritized the need to identify and address the consequences of flooding from a dam failure. Much of this work has involved the development of emergency action plans (EAPs) that describe the potential consequences of a dam breach and the actions required in response to those consequences. The breach of the dam is an extreme example of a dam-induced flood, because the flood that results from the breach far typically far exceeds the flood that would have resulted without the dam in place. While the induced flood resulting from dam failure remains of paramount importance, other induced flooding scenarios have important consequences for the dam safety community to consider. In a broad sense, dam induced flooding involves any flooding that results due to the presence of a dam greater than the flooding that would have occurred without the dam. Induced flooding can occur either upstream or downstream of a dam, or both. This presentation will outline several induced flooding scenarios and the potential consequences from each of the scenarios. The discussion of the scenarios will include a description of factors that influence the nature of induced flooding such as inflow event, spillway configuration, spillway layout, land use, land rights, operational options, and event preparedness. The discussion of the consequences will suggest ways to understand consequences and describe how an understanding of consequences from various induced flooding scenarios can help influence the planning, design, operation, management, and response to induced flooding events.