Selected Case Histories of Dam Failures and Accidents Caused by Internal Erosion

The vast majority of embankment dams have exhibited good behavior. However, about 50 percent of large embankment dam failures have been attributed to internal erosion. Therefore, a study of case histories of incidents (both accidents and failures) can be instructive. The purpose of this report is to aid in the risk analyses, in comprehensive facility reviews, and in decisions about modifying existing Bureau of Reclamation embankment dams. The goal has been to collect some helpful case histories of dam failures and accidents caused by internal erosion. Also, a few case histories of Reclamation's response to piping incidents at their dams and at one Bureau of Indian Affairs dam have been included. A careful review of a few case histories of dams that are similar to the one under study can result in better assessments of possible failure mechanisms and insights into factors that can contribute to satisfactory or poor performance of embankment dams. [USBR]