Colusa County, CA: flood risk, in FEMA's own numbers
On FEMA's National Risk Index, Colusa County scores at the 37.9th percentile for flood hazard, rated "Relatively Low" — below the national norm for flood hazard. The hazard here is driven by inland rivers and flash flooding rather than the coast — FEMA's model puts a flood event here at about once every 2 years. That's a county-wide figure, not a per-address one — FEMA's parcel maps are a live lookup, not a bulk file.
Mandatory flood insurance compliance in Colusa County
Homes with a federally backed mortgage inside Colusa County's mapped high-risk flood zone (the Special Flood Hazard Area, or SFHA) are legally required to carry an NFIP flood policy. In practice, 72.1% of them do — 354 active policies against 491 structures FEMA counts in that zone, leaving a real compliance gap. Looking beyond the mandated zone, 6.9% of all residential structures in Colusa County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
Where Colusa County ranks
Among the 3144 US counties FEMA scores for flood hazard, Colusa County ranks 2016 — 1 being the highest hazard nationally — and 1717 by population among all 3144 counties covered here, where 1 is the largest. Colusa County, California is home to about 22,074 people across 1,150.639 square miles of land.
Your street may differ from Colusa County's average
FEMA counts 6,907 residential structures in Colusa County overall, 474 of them carrying some form of NFIP coverage — but a lender or insurer cares about one parcel, not that county total.
Where Colusa County's figures come from
Every figure on this page traces to a named FEMA dataset, documented in the methodology guide. If you're unsure why any of this insurance requirement exists at all, the SFHA explainer covers it from first principles.