Communities downstream from a Northern California reservoir gushing water for the first time in 20 years braced for flash floods and evacuations after authorities warned them to prepare for rising rivers and creeks.

Northern California is forecast to get a brief break from persistent downpours Wednesday but the surge of water released from Don Pedro Dam into the Tuolumne River in the foothills east of Modesto is expected to reach overtopped levees later in the day.

Katie Whitley, who manages the Driftwood Mobile Home Park in Modesto, said residents nearest the river have been moving their trailers out since the start of the weekend.

“We’re just holding our own,” Whitley told the Los Angeles Times. “That’s what we have to do. You just have to hope for the best. But you can expect it when you live on the river.”

The water released from Don Pedro is expected to reach its peak along a stretch near Vernalis that’s already at danger stage, said Tim Daly, a spokesman for the San Joaquin County Office of Emergency Services. The water isn’t expected to spill over the levees but rather increase pressure on them, causing possible breaks in any weak places.

Farther south, the Anderson Dam in Santa Clara County reached capacity over the weekend and after heavy rain it began overflowing into the Coyote Creek.

Rescuers chest-deep in water steered boats full of people, some with babies and pets, from a San Jose neighborhood inundated Tuesday by water from the creek.

At least 225 residents were taken to dry land and rinsed with soap and water to prevent them from being sickened by floodwaters that had traveled through engine fuel, garbage, debris and over sewer lines, said San Jose Fire Captain Mitch Matlow.

Rescuers went door-to-door searching for people who needed to leave the neighborhood. Only residents who could prove they had been cleaned of the floodwaters were allowed to board buses to shelters.

“The water started to seep in the driveway, and then it started to creep up into the front door. It kept getting worse and worse,” said Alex Hilario, who walked in knee-high water to get to his car and leave.

Earlier Tuesday, firefighters rescued five people stranded by flooding at a homeless camp along the same creek in San Jose.

Firefighters knocked on doors to tell residents to get out of their homes because the city does not have sirens or another emergency warning system, San Jose spokesman David Vossbrink said.

The rains were the latest produced by a series of storms generated by so-called atmospheric rivers that dump massive quantities of Pacific Ocean water on California after carrying it aloft from as far away as Hawaii.

In the Sierra Nevada range, one of the main routes to Lake Tahoe was in danger of collapsing after a roadway shoulder gave way following heavy storms, leaving a gaping hole on part of Highway 50, Caltrans engineer Jarrett Woodruff said.

Crews opened one lane Tuesday as Caltrans workers tried to fix the road failure after numerous mudslides blocked it for days in recent weeks.

The water level rose at Lake Oroville for the first time since authorities ordered an emergency evacuation of 188,000 people more than a week ago after a damaged spillway caused major flooding concerns.

The rains have saturated the once-drought stricken region and wreaked havoc for residents hit hard by the heavy rain. At least four people have died in the storms throughout the state in the last week.

(AP)