Dam Failure
Folsom Dam Failure
Folsom Dam failure is unlikely. However, if a catastrophic failure were to occur it would be a major concern.
July 17, 1995 - Folsom Dam, spillway gate #3 failed causing significant flows in the American River.
Likelihood of Future Occurrence: Unlikely
Likely Disruptions
Disruptions of a major dam failure may include:
Physical Safety - threat to life and property, including buildings, its contents, and use - could result in EVACUATIONS
Food, Drinking Water, and Cooking
Power Outages
Fuel supply
Shelter & Clothing
Water & Sewer
Transportation (e.g., bridge foundations damaged, roads washed out)
Medical services
Spiritual and Emotional Needs
According to the Sacramento County General Plan Background report, there are four major and two minor dams which, if they fail, may impact the people and resources of this jurisdiction. The major dams are comprised of Shasta on the Sacramento, Oroville on the Feather, Comanche on the Mokelumne and Folsom on the American. The minor dams include Nimbus and Rancho Seco. All of these 6 dams are high hazard dams. More specific information about these dams can be found in Figure 4-22 and Table 4-25 in Section 4.2.9 of the LHMP. According to the report, a catastrophic failure of any of these dams could have a significant impact on the County. The failure of any of these dams would cause downstream flooding and would likely result in loss of life and property. The potential magnitude of a dam failure depends on the time of year and the base flow of the river when the failure occurs. During the winter months, when river flows are higher, the impact to the area would be much greater and evacuation times much less.
