A 1975 earthquake near Oroville, Calif., halted construction of nearby Auburn Dam on the American River’s North Fork, and the project lingered in a vegetative state for 33 years. On Dec. 2, the dam died when the State Water Resources Control Board revoked the project’s water rights. The dam project was authorized in 1965 for the Central Valley Project with an estimated cost of $282 million, but it would cost $6 billion to $10 billion to complete now, says a U.S. Bureau of Reclamation official.

BuRec held rights for 2.5 million acre-ft of water in connection with Auburn Dam. Following the revocation, three applications for water rights in the watershed are pending with the water resources board, says William L. Rukeyser, board spokesman. Sacramento Municipal Utilities District has filed two applications for a total of 27,200 acre-ft and San Joaquin County is requesting 147,000 acre-ft. All are for appropriative rights, Rukeyser says.

Auburn was designed as a concrete double-arch gravity dam, 685 ft high and 4,150 ft long. Buildings, access roads, a boat ramp and a 33-ft-long diversion tunnel were completed and foundation work was in progress in 1975 when an earthquake measuring 5.7 on the Richter scale struck about 50 miles away. “The event raised concerns about the safety of dams such as the thin-arch concrete dam proposed,” says a 2006 study by MWH Global for the Bureau of Reclamation.

Completing Auburn Dam now would cost $6 billion to $10 billion with a redesign.

“If we were to construct it again, we would go with either a roller-compacted or concrete-gravity dam downstream of where we were,” says Rick Johnson, BuRec deputy manager of the Central California Area office. The agency does not have active plans to complete the project.