Safeguard Embankment Dam Safety

Unlike concrete dams, embankment dams are less demanding in their foundation requirements. Thus, with careful design and construction control, embankment dams can be founded on a variety of soil and rock sites. On the other hand, due to diverse geological origins of the foundation, it is important to anticipate and identify correctly potential problems associated with this type of dam including its foundation. Embankment dams are vulnerable to the overtopping mode of failure. Once overtopped, an embankment dam is often doomed to be down cut by the erosion of released water, resulting in dam breach and downstream flooding in rapid succession. Embankment dams are used to retain water, mine tailings and other materials in liquid and/or solid phase. Release of retained materials in case of dam incident or breach could subject the downstream area to environmental pollution in addition to flood inundation.

This paper provides an overview of embankment dams, including tailings dams, and an overview of key natural and human hazards and factors that pose threat to this type of dam. The paper then reviews incidents and failures of embankment dams, the failure impacts and emergency response measures. Two recent cases of dam failure and incident are used to illustrate how these threats are continually frustrating our effort in managing dam safety in the 21st century. This paper concludes with some thoughts that might help us transform recent set backs to a compelling driving force to reduce the frequency and severity of future dam incidents.

Lo, R.C. 2019. “Safeguard Embankment Dam Safety,” in Proceedings of the 87th Annual Meeting of International Commission on Large Dams (ICOLD), 9-14 June 2019. Ottawa, ON: Canadian Dam Association.