Flames were racing toward homes and burned across the Hidden Valley Golf Club course, but with the aid of air attacks, crews were able to stop the advance.
Two firefighters were injured battling the fire.
Voluntary evacuations are in effect in the area of Vandermolen Drive, Valley Drive, Fresian Street and Cross Rail Lane in Norco. Residents are being evacuated to Ingalls Park.
"Next thing you know it's coming over my hill here, so we've been off loading a bunch of stuff, getting it all ready to go in case we have to," said Norco resident Steve Potts.
"I've got good confidence in these guys, you know what I mean? They look like they know what they're doing. They've got a lot of air support and everything else, so it shouldn't be too bad," added Potts.