Safe Zone Determination under the Dam Failure Condition

Hundreds of dam failures have occurred throughout U.S. history. These failures have caused immense property and environmental damage and have affected thousands of lives. As the nation’s dams age and downstream populations increase, the potential for dam failures that result in life loss grows. While failure during flood conditions typically defines the upper limit of inundation, there is less potential for loss of human life because the downstream population is “on alert.” During flood conditions, public alerts and emergency notifications can provide an early warning lowering the risk of human life loss. Considering this, fair weather failure is generally thought to have the most potential for life loss, primarily due to its element of surprise. This study focuses on the sunny day dam failures and highlights opportunities for reducing the element of surprise. For example, historical fatality data resulting from dam failures clearly show that consequences could have been much worse if the dam had failed at night with no warning. This paper will discuss potential low-cost risk mitigation strategies that can reduce the consequences resulting from dam failure. Using data from multiple simulations of historical dam failures, this paper distinguishes safe zones from extremely vulnerable inundation areas. These safe zones can be used by appropriate agencies to enhance public safety and implement guidelines to mitigate consequences in the event of a dam failure.