There are are more than 80,000 dams in the United States, according to the 2007 update to the National Inventory of Dams. Approximately one third of these pose a "high" or "significant" hazard to life and property if failure occurs.
There are fourteen dams which could have a significant impact on Ventura County residents in the event of dam failure. Ten of these dams are in Ventura County and include: Bard Reservoir, Casitas Dam, Lake Eleanor, Lake Sherwood, Las Llajas, Matilija Dam, Runkle Debris Basin, Santa Felicia Dam, Senior Canyon, and Linaloa Lake. The four in Los Angeles County include: Bouquet Canyon Dam, Castaic Dam, Pyramid Dam and the Westlake Reservoir.
Dam failure or levee breeches can occur with little warning. Intense storms may produce a flood in a few hours or even minutes for upstream locations. Flash floods occur within six hours of the beginning of heavy rainfall, and dam failure may occur within hours of the first signs of breaching.
Other failures and breeches can take much longer to occur, from days to weeks, as a result of debris jams or the accumulation of melting snow.
In those cases where flood waters could have a life threatening impact within a short period of time, residents should move to higher ground.
How can I protect myself?