Hamilton County, IN flood risk explained
Flood hazard in Hamilton County sits at the 91.1th national percentile, a middling flood hazard by national standards; driven by inland rivers and flash flooding rather than the coast — FEMA's model puts a flood event here at about 1.8 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.
Hamilton County's flood-insurance compliance gap
Homes with a federally backed mortgage inside Hamilton 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, 16.2% of them do — 214 active policies against 1,320 structures FEMA counts in that zone, leaving a real compliance gap. Looking beyond the mandated zone, 0.5% of all residential structures in Hamilton County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
Hamilton County against the rest of the country
Among the 3144 US counties FEMA scores for flood hazard, Hamilton County ranks 299 — 1 being the highest hazard nationally — and 201 by population among all 3144 counties covered here, where 1 is the largest. About 379,704 people live in Hamilton County, Indiana, spread over 394.39 square miles.
Your street may differ from Hamilton County's average
523 of Hamilton County's 115,798 residential structures carry flood coverage of some kind, per FEMA's latest count — useful context, not a substitute for checking one parcel.
Where Hamilton 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.