About 163 people have been taken to the hospital. A group of up to 300 people are stranded in Romero Canyon, east of Santa Barbara.
Police said the scene at the site of the landslides "seeded like a First World War battlefield".
Rescue agencies said the death toll is expected to continue to rise. Thousands of people have been evacuated from the flood, and more than 50 rescue efforts have been launched.
Mr. Mike Eliason - a spokesman for the Santa Barbara District Fire Department - said that heavy rain caused mud to overflow into the Montecito residential area, causing many houses to collapse. Among the rescued people, there is a 14-year-old girl who was trapped for many hours in the middle of a collapsed house
Santa Barbara Chief of Fire Department Dave Zaniboni said five people died in Montecito on January 9. The upper-class neighborhood where the incident occurred has the homes of many famous people such as actor Rob Lowe, MC Ellen DeGeneres, and TV queen Oprah Winfrey.
The US Coast Guard has sent a space support vehicle to participate in rescue operations.
Forest fires in December 2017 occurred in areas where vegetation had been burned to prevent flooding and landslides. About 30,000 California residents have been asked to evacuate since January 8, the second in two months in the area. In particular, in the Burbank area, where mud was washing away vehicles, officials issued a mandatory evacuation order.
Floods and landslides have affected areas that were damaged by forest fires last month and caused the large coastal expressway to stop operating for about 48km. According to BBC reporters, the rocks rolled down the hillside and blocked many roads.
After the forest fire, the forest carpet was burned and the soil was heated, creating an water retention barrier that blocked the seepage, leading to an increased risk of landslides and flooding, according to the BBC.
