History of the Auburn Dam
In 1964, Congress authorized the Auburn Folsom-South Unit due to the threat of increased flooding, which was estimated to be completed in 8 years at the time. The main feature was the multi-purpose Auburn Reservoir, which provides water supply, power, recreation, fishery enhancement, and additional flood protection.
In 1975, work on the foundation of a 685-foot-high double curvature concrete arch dam was under way, but an earthquake in Oroville cast doubt on the seismic stability and suspended construction.
In 1980, a concrete gravity dam was proposed by the Secretary of the Interior. It would be curved to match the previously prepared foundation of the original arch dam.
In 1985, Bechtel proposed a concrete gravity dam with straight axis because savings in concrete would offset added costs of foundation preparation in USBR’s curved gravity dam.
February 1986, major flood caused record releases from Folsom Dam. If the storm lasted longer, a major levee failure could have occurred.
March 1987, the Corps report reveals that the Folsom Reservoir provides a lower level of flood protection than previously believed, subjecting major metropolitan areas and people to a significant risk from flooding caused by levee failures in a 200-year flood. The required amount of storage could only be obtained only via an Auburn Reservoir.
July 1987, USBR reported an appraisal of a number of alternative sizes of Auburn Reservoir, ranging from a 315,000 acre-foot single purpose flood control reservoir to the original 2,300,000 acre-foot multi-purpose proposal, cost ranging from $240 million to $1.1 billion. It presented a wide variety of cost allocation alternatives, but no recommendations were made.1
Aftermath: The Auburn Dam was never built and was halted due to extensive seismic and geologic studies. It became economically infeasible and could not be financed by the State. Current studies show that it would cost over $6 billion to build the Auburn Dam. It is more practical to make modifications to the existing Folsom dam and make levee repairs to minimize the threat of flood damage.2
1. Auburn Dam Report: Reconnaissance appraisal of construction under state sponsorship. Department of Water Resources. December 1987. pg 1-3.