Marion County, OH: flood risk, in FEMA's own numbers
On FEMA's National Risk Index, Marion County scores at the 64.9th 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 2 times a year. This describes the county, not any one street — FEMA only publishes exact parcel zones through a live map service.
Marion County's flood-insurance compliance gap
22.8% of the homes FEMA requires to carry flood insurance in Marion County — those inside the mapped Special Flood Hazard Area — actually have a policy in force: 169 policies against 742 mandated structures, which means a meaningful share of legally-required coverage simply isn't there. Looking beyond the mandated zone, 0.7% of all residential structures in Marion County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
How Marion County compares nationally
Among the 3144 US counties FEMA scores for flood hazard, Marion County ranks 1151 — 1 being the highest hazard nationally — and 844 by population among all 3144 counties covered here, where 1 is the largest. Marion County, Ohio is home to about 64,976 people across 403.807 square miles of land.
What to do next if you own or are buying in Marion County
FEMA counts 25,935 residential structures in Marion County overall, 183 of them carrying some form of NFIP coverage — but a lender or insurer cares about one parcel, not that county total.
Where Marion 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.