Rivers are rising, trees are toppling and major roadways are closed by mudslides and flooding as a powerful winter storm pummels Northern California.

With the region soaked by a weekend of heavy rain, flash flood watches and warnings were in place across the region late Sunday. In Sonoma County, north of San Francisco, about three thousand people in the Russian River communities of Guerneville and Monte Rio were told to evacuate as the river gets close to flooding. Sheriff’s deputies and firefighters were busy into the night Sunday helping area residents leave the area.

“I’ve got people moving cars, trailers and stuff,” Monte Rio Fire Chief Steve Baxman told the Press Democrat. “People are getting ready. They know what to expect.”

Russian River expected to top its banks

The National Weather Service reports that nearly 12 inches of rain fell in a 24-hour period at one of its observation stations near Guerneville, with more rain expected on Monday. With all that precipitation the Russian River was expected to hit flood stage late Sunday and overflow its banks early Monday. Local flooding was being reported across the county on Sunday, as well as road closures caused by local streams over flowing and by falling trees.

Thousands throughout Bay Area without power

In San Francisco and across the Bay Area toppling trees and strong winds were being blamed for knocking out electrical service to tens of thousands of people.

Pacific Gas & Electric Co. said late Sunday that about 17,000 people without power in various outages across the region. Crews were expected to be working throughout the night in trying to restore service. At San Francisco International Airport some arriving flights were being delayed by nearly four hours because of the weather.

Well south of San Francisco, Highway 1, the scenic roadway through the rugged Big Sur region was closed Sunday night because of mudslides and rocks falling onto to the roadway. Caltrans officials said crews would assess the highway early Monday to see if it could be opened again.

Local highways were also closed throughout the Sana Cruz Mountains because of flooding.

Snow, mudslides close I-80

In the Sierra Nevada, I-80, a major freeway that runs from San Francisco to Reno, Nevada and beyond, was closed in both directions between the city of Truckee and Donner Summit because of snow and mudslides.

With heavy and wet snow falling in the mountains and rain expected to continue into the night in the lower elevations, the California Highway Patrol could not say late Sunday when the roadway would be opened again.