A particularly wet winter has caused more than 600 landslides across California since Dec. 30, 2022, according to the California Geological Survey.

The West Coast has been battered by rain and snow over the past month, and the wet conditions have left behind significant flooding, downed trees and landslides.

According to a map shared by the Geological Survey, the areas hardest hit by landslides are in the Bay Area, Central California near Fresno, and Southern California near Ventura.

California landslides since Jan. 1, 2023 (California Geological Survey)

Officials in Ventura County said it could take up to three weeks to clear the only road into the remote canyon community of Matilija in the Los Padres National Forest near Ojai. Repairs could take six months. More than 70 residents were evacuated by helicopter, but a handful have refused to leave, according to the Ventura County Sheriff’s Office.

“Towering piles of rock and mud reach over 40 feet tall in some locations, blocking access to roadways and leaving residents isolated to the canyon,” the sheriff’s office said in a weekend statement.

The nine atmospheric rivers since late December caused power outages, flooding, levee breaks, washouts and landslides nearly statewide. At least 20 people were killed.

5 Freeway mudslide
Some lanes on the 5 Freeway in Elysian Park were blocked by a landslide following the storm on Monday, Jan. 9, 2023. (KTLA)

Much of the flooding across the state has been fast and dangerous. In Paso Robles, a 5-year old boy was swept out of his mother’s arms by rising floodwaters.

On Jan. 12, Governor Gavin Newsom asked President Biden for an Expedited Major Disaster Declaration, and two days later it was granted. Federal assistance will now be available to California to help support relief programs for individuals and public infrastructure.

The Associated Press contributed to this report.