Scott Knippelmeir didn’t seem overly concerned by the mudslide that happened just below his house on Fitch Mountain in Healdsburg on Friday morning.

That section of the hill had “slipped once before, in 1985,” said Knippelmeir, a viticulturist who explained that heavy rains, following dry conditions all fall, caused the soil to “liquefy and flow.”

It wasn’t the volume of rain, he said, as much as it was the soil conditions. “It’s rained this much before.”

On that last point, meteorologists beg to differ.

As of 4 p.m. Friday, 12.47 inches had fallen on Santa Rosa since a massive atmospheric river barged into the North Bay early Wednesday.

That volume of precipitation, said Rick Canepa, a meteorologist for the National Weather Service, was the most since the service began keeping records on June 1, 1902.

Santa Rosa’s former three-day record of 9.96 inches was set from Oct. 23-26, 2021.

On Thursday, Santa Rosa recorded 5.45 inches of rainfall, marking the third-highest single-day total on record. Wednesday’s total of 4.15 inches came in at No. 10 on the all-time list of Santa Rosa’s rainiest days. Another 2.87 inches fell Friday, putting the three-day total over a foot.

Respite at last

By 4 p.m. Friday afternoon, those Old Testament rains had begun to abate in the North Bay.

“The heaviest rain band is now moving to the east and south,” said Canepa, who predicted “off-and-on showers” Saturday, with up to a tenth of an inch, followed by a possible third of an inch Sunday — “a dramatic drop-off from what we’ve had.”

Day 3 of this historic storm saw at least 10 schools closed across the county. As of 6 p.m. Friday, 406 PG&E customers were without power, 219 of those in Rio Nido, despite the nonstop work of emergency crews.

Swollen with runoff, the Russian River had risen to 31.6 feet by 5 p.m. Friday, a half-foot below “minor flood” levels.

The river was projected to crest at 34.2 feet at 5 a.m. Saturday — up nearly 6 feet from 9 a.m. Friday, according to the National Weather Service Prediction Center. Residents near the river are advised to remain vigilant.

Starting at 2 p.m. Friday and continuing until further notice, the National Weather Service issued a flood warning for areas near the Russian River west of Guerneville, including Guerneville, Forestville and Monte Rio.

Flooding and downed trees resulted in the closure of at least two dozen roads, while others were barely passable.

Farther upstream in Hopland, Mendocino County, the river exceeded the minor flood level around 6 p.m. Thursday before receding. By 6 p.m. Friday the water level was at 14.3 feet, and was expected to drop another nine feet by Sunday afternoon.

Rescue required

In Santa Rosa, firefighters pulled a woman from her half-submerged compact car, which had come to rest in a flooded culvert at Brookwood Avenue and Bennett Valley Road.

According to Fire Division Chief Paul Lowenthal, the woman drove into the flooded area, unaware of how deep the water was.

“That really highlights why we’re trying to get folks not to drive through flooded areas,” he said. “It pulls police and fire away from other critical calls, and it’s avoidable.”

Lowenthal said the incident was one of several calls Friday morning, including reports of downed power lines, fallen trees and nuisance flooding, which he anticipated would ease by evening.

“Hopefully people heed the warnings as the bands of rain move through and limit unnecessary travel and storm-related accidents.”

Among the many schools — and school districts — announcing closures was Marguerite Hahn Elementary School in Rohnert Park, which dismissed students early Friday due to flooding, school officials announced to parents in a ParentSquare message.

Eric Wittmershaus, director of communications for the Sonoma County Office of Education, said localized flooding complicated pickup efforts.

By around 12:30 p.m., district officials arranged buses to transport students to the Rohnert Park Community Center for pickup, he said.

Similar flooding concerns at Lawrence E. Jones Middle School prompted school officials to notify parents to pick up their children early Friday afternoon, Wittmershaus said.

Urban areas and creeks were experiencing significant flooding Friday, but conditions were expected to improve as the rain let up, according to the National Weather Service.

Quick work mitigates damage

In the immediate aftermath of Friday morning’s mudslide on Fitch Mountain, Knippelmeir and his neighbors got to work. “We tarped the whole hillside, and diverted downspout water away from the slide,” he said. Had they not, he believes, the incident might have been more serious.

Late Friday afternoon he was at his in-laws’ place in Healdsburg after Sonoma County officials placed a “yellow card” on his house.

The yellow card meant that Knippelmeir and his wife couldn’t stay in their house until it’s checked out by a geotechnical engineer, who was scheduled to come by Saturday.

Knippelmeir was confident the house will pass inspection. Since the last slide in 1985, it’s been “retrofitted with a couple hundred thousand dollars of foundation work.”

Meanwhile, he and his wife had plans for Friday night. They intended to find a bar, he said, “and order mudslides.”

You can reach Staff Writer Austin Murphy at austin.murphy@pressdemocrat.com or on Twitter @ausmurph88.