Auburn Dam

Auburn Dam was a proposed dam on the North Fork of the American River east of the town of Auburn, California in the United States, on the border of Placer and El Dorado Counties. Slated to be completed in the 1970s by the U.S. Bureau of Reclamation, the concrete arch-gravity dam would have been over 700 feet (210 m) high, straddling a gorge downstream of the confluence of the North and Middle Forks of the American River and upstream of Folsom Lake. It would have regulated water flow and provided flood control in the American River basin as part of Reclamation's immense Central Valley Project.

Proposals and studies for the dam emerged in the late 1960s, and construction work commenced in 1968, involving the diversion of the North Fork American River through a tunnel and the construction of a massive earthen cofferdam. Following a nearby earthquake and the discovery of a seismic fault that underlay the dam site, work on the project was halted for fears that the dam's design would not allow it to survive a major quake on the same fault zone. Although the dam was redesigned and a new proposal submitted by 1980, spiraling costs and limited water storage offered by either design put an end to the project until heavy floods destroyed the cofferdam, sparking brief renewed interest in the dam. The California State Water Resources Control Board denied water rights for the dam project in 2008 due to lack of implementation.

Although new proposals surfaced from time to time after the 1980s, the dam was never built for a variety of reasons. Limited flood-control capability, geologic instability, and potential harm on recreational and ecological values finally put an end to the Auburn Dam project. Many of the original groundworks and preliminary constructions at the Auburn Dam site still exist, and up to 2007, the North Fork American River still flowed through the diversion tunnel that had been constructed in preparation for the dam. Reclamation and Placer County Water Agency completed a pump station project that year which blocked the tunnel, returned the river to its original channel, and diverted water through another tunnel under Auburn to meet local needs. However, some groups continue to support construction of the dam, which they claim would provide important water regulation and flood protection.