New aerial video from Saturday shows a waterlogged Russian River Valley, shot from "Sonoma One," the County Fire District's new chopper.
Saturday's reconnaissance mission showed swollen creeks and lagoons which normally take overflow from the Russian River, now reaching the top of their banks.
ABC7 News was there when Sonoma County Fire District Chief Mark Heine landed after surveying the rising water and with more storms on the way, his impressions were sobering.
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"I think the flooding we're going to see will reach disaster proportions, getting into businesses, residences and cutting off access roads," Heine said.
Many folks in Guerneville have been getting ready this week for flooding and possible evacuations, stacking sandbags around shops and homes.
"Right now, we don't have any power, we haven't had power since Wednesday afternoon," said Daniel Falcon-Schneider.
Falcon-Schneider lives in Cazadero where toppled trees are everywhere.
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"Looks like a tornado went through. You couldn't see the asphalt, just all the branches," said Falcon-Schneider.
He worries flood water from the river could leave him stranded.
"My biggest fear is being stuck on the other side of Guerneville: west," he added.
The Russian River isn't the only area first responders are concerned about, many are watching flood-prone Santa Rosa Creek, preparing for possible water rescues.
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The Santa Rosa Fire Department's Swift Water Rescue Team was doing last-minute training on the Russian River and Santa Rosa Creek, ready to respond to emergencies in real-time.
"They've been busy not only training but pre-surveying our creeks and streams finding problem spots so we're doing everything we can to be prepared," said Santa Rosa Fire Marshal Paul Lowenthal.
Firefighters urge folks living near creeks and rivers to be ready to leave their homes if water starts to rise.
"Have a plan B and have a Go-Bag packed, consider where you will go and how you'll connect with family members if you lose power," Heine said.