Preparedness for Dam Failures in the San Francisco Bay Area

Abstract

In California, past high-magnitude earthquakes have mostly occurred before the largest water storage dams were built or while reservoirs were at abnormally low storage levels. While regulations and procedures concerning preparations for possible dam failure appear strong on paper, at least in the San Francisco Bay Area actual preparedness seems inadequate. Few cities have specific dam failure emergency plans, and basic information concerning impacts and responses is generally out of date. The risk of dam failure is uncertain, but given the high probability of a major earthquake occurring in the San Francisco Bay Area in the next 30 years, the aging of dam structures, and the intense development of inundation areas, dam failure and preparedness for such an event appear to require greater attention. Standard emergency management procedures will likely not cope well with a dam break scenario, and current information on potential impacts commonly reflects decades-old inundation forecasting methods. While tools exist to develop and implement more systematic, focused, and updatable preparedness plans, their use would likely carry a hefty price tag.