GUERNEVILLE, Calif., - People who live along the Russian River in Sonoma County have been under an evacuation warning since Wednesday.
Authorities are now urging people to leave before it becomes an order when it's mandatory to leave.
On Friday, rescue crews and residents prepared for weekend rain and wind.
A crew from fire station nine in Guerneville participated in flood rescue training on the Russian River.
Captain Stephan Mercieca with the Sonoma County Fire District showed KTVU the treacherous conditions that crews have to face even before the river reaches flood stage.
"This is what we had in the river this morning," said Mercieca as he pointed to an inflatable rescue boat used in the practice on the Russian River which is projected to reach flood stage.
"The water is very brown. You can't see anything in it, zero visibility. There's a ton of debris, tree limbs and stumps, full-sized logs coming at us," Mercieca said. "We saw somebody's deck floating down, that had floated away from their house."
Dangerous debris captured with the use of video was captured on their helmet cams.
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Mercieca said stormy conditions are the best times for his crews to test equipment and brush up on skills.
On Friday night, the parking lot at Johnson Beach was already underwater, 48 hours prior, the area was completely dry.
"I just came to see how high the river was," longtime Guerneville resident Bonnie Hunt said. She evacuated from her home Wednesday when the power went out during the storm.
"I've moved almost everything out of my house I spent the last two days in a motel because I thought it was going to go up high," Hunt said.
The Sonoma County Fire District shared video of Russian River captured Friday from its new helicopter on its first winter storm aerial recon mission showing extremely high water levels.
"We're already seeing some significant flooding and significant impacts where it's high…more rain comes in and rain drains into it, and it's going to spread out," said Karen Hancock with the Sonoma County Fire District.
Authorities are urging people with mobility or medical issues, people with animals, and older folks to evacuate before it becomes mandatory.
Officials told KTVU when flooding causes road closures, there will be limited routes to get out of the area.
Amber Lee is a reporter with KTVU. Email Amber at Amber.Lee@Fox.com or text/leave message at 510-599-3922. Follow her on Facebook @AmberKTVU, Instagram @AmberKTVU or Twitter @AmberKTVU