Many roads are under two feet of water in San Rafael, and city officials said there have been over 330 calls for fire or police assistance, four times the average call volume according to CBS San Francisco.
The National Weather Service in Sacramento warned of "potentially historic" rain for the city's downtown.
North of the state capitol in Butte County, California's Highway Patrol closed down State Route 70 due to mudslides and debris flows near the now-contained Caldor Fire, which scorched more than 346 square miles of the Sierra Nevada and burned hundreds of homes.