Grundy County, IA flood risk explained
Flood hazard in Grundy County sits at the 14.2th national percentile, among the lowest flood hazard in the country; driven by inland rivers and flash flooding rather than the coast — FEMA's model puts a flood event here at about 1.6 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
20% of the homes FEMA requires to carry flood insurance in Grundy County — those inside the mapped Special Flood Hazard Area — actually have a policy in force: 2 policies against 10 mandated structures, which means a meaningful share of legally-required coverage simply isn't there. Looking beyond the mandated zone, 0.1% of all residential structures in Grundy County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
Grundy County against the rest of the country
Among the 3144 US counties FEMA scores for flood hazard, Grundy County ranks 2727 — 1 being the highest hazard nationally — and 2260 by population among all 3144 counties covered here, where 1 is the largest. Grundy County, Iowa covers 501.855 square miles and counts roughly 12,405 residents.
What to do next if you own or are buying in Grundy County
3 of Grundy County's 5,576 residential structures carry flood coverage of some kind, per FEMA's latest count — useful context, not a substitute for checking one parcel.
Where Grundy 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.