Atchison County, KS: flood risk, in FEMA's own numbers
On FEMA's National Risk Index, Atchison County scores at the 21.7th percentile for flood hazard, rated "Very Low" — among the lowest flood hazard in the country. 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 1.9 times a year. That's a county-wide figure, not a per-address one — FEMA's parcel maps are a live lookup, not a bulk file.
Who actually carries the flood insurance FEMA requires
Out of 54 homes FEMA counts inside Atchison County's mapped flood zone, 10 carry the flood policy federal law requires there — 18.5% compliance, short of full coverage. Looking beyond the mandated zone, 0.2% of all residential structures in Atchison County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
Atchison County against the rest of the country
Among the 3144 US counties FEMA scores for flood hazard, Atchison County ranks 2505 — 1 being the highest hazard nationally — and 2017 by population among all 3144 counties covered here, where 1 is the largest. Atchison County, Kansas is home to about 16,249 people across 431.174 square miles of land.
What to do next if you own or are buying in Atchison County
FEMA counts 7,644 residential structures in Atchison County overall, 12 of them carrying some form of NFIP coverage — but a lender or insurer cares about one parcel, not that county total.
Where Atchison 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.