Auburn Dam, Arch dam project in Auburn, California, United States

Auburn Dam is an unbuilt concrete arch dam planned for the North Fork American River near Auburn, California. The site shows a deep rectangular basin with dark blue water against stepped rock walls, unpaved switchback roads and benches cut into the hillside, and exposed light-colored rock faces. The dam was designed to stand 680 feet (210 m) tall and store 2,300,000 acre-feet of water.

Auburn Dam was first proposed in the 1950s, and Congress authorized the Auburn-Folsom South Unit of the Central Valley Project in 1965 with a target completion date of 1973. Construction began in 1968 with a diversion tunnel and a massive earthen cofferdam. Work halted after a nearby earthquake and the discovery of a seismic fault beneath the site; a redesigned proposal was submitted by 1980, but costs ended the project, and the State Water Resources Control Board denied water rights in 2008.

The unfinished dam site reflects California's ongoing debates between water management and environmental protection in the American River basin. These conversations still shape how people view river use and natural spaces in the region today.

The site lies east of Auburn, on the border of Placer and El Dorado Counties, reached via the Auburn-Foresthill Road area. The river was returned to its original channel in 2007 after the pump station project blocked the diversion tunnel, so the old channel and tunnel portals are no longer a through-route. Expect uneven ground and exposed rock; carry water.

The project would have stored about 2.3 million acre-feet of water, an enormous supply for the region's water needs. The tunnel structures built to divert the river during construction remain visible today as engineering remnants.