GUERNEVILLE (CBS SF) — Residents living along low-lying areas around Russian River and its tributaries are being asked by Sonoma County sheriff’s officials to evacuate Thursday if they live below 36 feet sea level, a sheriff’s spokesman said.

The river is forecast to crest at 36 feet at 1 a.m. Friday and will not fall below flood stage until 10 p.m.

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Flood stage is 32 feet, according to the National Weather Service.

“There could be several thousand people affected,” sheriff’s spokesman Sgt. Spencer Crum said.

He said they don’t know exactly how many people because some homes are vacation homes.

Sheriff’s officials have put out advisories on Nixle, Nextdoor, Facebook and Twitter and they sent out wireless emergency alerts and reverse 911 calls.

Major damage isn’t expected, Crum said.

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“We don’t’ typically get major damage until 40 feet,” he said.

Weather officials said as of 4 p.m., the river was at 33.5 feet. An interactive map of flood stages on the river can be found at the Sonoma County Emergency and Preparedness website.

Crum urged people to avoid driving on roads that are flooded.

“Turn around, don’t drown,” he said.

Residents and visitors can get updates on the storm on the Sonoma County website. Locations of sandbags can also be found on the county’s website.

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