How much flood risk does Adams County actually carry?
Adams County lands at the 11.5th percentile of FEMA's National Risk Index for flooding, "Very Low" territory — among the lowest flood hazard in the country — with the hazard driven by inland rivers and flash flooding rather than the coast — FEMA's model puts a flood event here at about once every 1 years. 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
2.6% of the homes FEMA requires to carry flood insurance in Adams County — those inside the mapped Special Flood Hazard Area — actually have a policy in force: 1 policies against 38 mandated structures, which means a meaningful share of legally-required coverage simply isn't there. Across all residential structures in Adams County, not just the ones FEMA mandates, 0.1% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
Adams County against the rest of the country
Adams County sits at rank 2802 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 2914 of 3144 by population (1 is biggest). Adams County, Iowa covers 423.433 square miles and counts roughly 3,606 residents.
Checking a specific address in Adams County
Across all of Adams County's 2,420 residential structures, 2 carry an NFIP policy today — a county-wide count that still can't tell you one address's own mapped zone.
More on how this number was built
The methodology guide shows exactly which FEMA and Census tables feed Adams County's numbers. The guide to what the Special Flood Hazard Area actually means explains why the mandatory-insurance rule exists and who it applies to.