Emergency response crews have contained a fire at the 114-MW Ronald B. Robie Thermalito pumped-storage facility, but officials from the California Department of Water Resources (DWR) are still trying to determine its cause.
The Thermalito pumped-storage plant, located downstream of Oroville Dam on the Feather River, was not damaged as badly as investigators originally feared, though the project won't be able to produce energy until repairs can be completed.
The blaze began the morning of November 22 and is believed to have started in the plant's control room. A fire department official said an automatic suppression system was activated but unable to contain the fire.
Fire fighters were able to fight it from inside the building that Thursday until they were forced to withdraw due to heavy smoke.
Officials say they initially thought it might have taken several days for the fire to burn itself out, but crews were able to take a preliminary damage assessment earlier this week.
Four of Thermalito's five stories are located below ground. The bottom two were not damage, the third had fire and heat damage, and the first subterranean floor -- where the control room is located -- sustained significant fire and heat damage. The top floor had smoke damage.
DWR says Thermalito provides about 5% of the power for the California State Water Project, but that electrical service and water deliveries will not be interrupted by the fire.