Thunderstorms dumped heavy rain across the northern Sacramento Valley Friday evening, triggering a flash flood warning for parts of Colusa County and turning otherwise quiet farm country into a risky place to be on the road.
The National Weather Service warned that sudden runoff could quickly flood low-lying roads, underpasses and farm fields, making travel hazardous in rural stretches around Maxwell and Delevan. As reported by The Sacramento Bee, Doppler radar showed intense downpours over the warned area, prompting the advisory for Colusa County.
What the NWS warned
The National Weather Service in Sacramento said Doppler radar was tracking thunderstorms producing heavy rain across the warning polygon and urged drivers to follow the familiar mantra: "turn around, don't drown" if they come across flooded roads. NWS Sacramento noted that as little as 6 inches of fast-moving water can knock a person off their feet, and around 12 inches is enough to carry away most vehicles.
Where flooding is most likely
Low-lying county roads, culverts and the network of irrigation and drainage ditches around the Colusa National Wildlife Refuge and nearby Delevan areas are particularly prone to sudden runoff when storms like this roll through. The U.S. Fish & Wildlife Service's information on the Sacramento National Wildlife Refuge Complex points out that flat refuge access roads and surrounding wetlands sit in a floodplain that can fill up fast during heavy rain.
How to stay safe
If you are in the warned area, avoid driving through standing water and head for higher ground when you can. Do not try to drive around barricades or push through flooded underpasses; the water is often deeper and faster than it looks. For the latest forecasts and warnings, follow the National Weather Service in Sacramento and local emergency channels.
