Winnebago County, IL flood risk explained
Flood hazard in Winnebago County sits at the 94.4th national percentile, well above the national norm for flood hazard; driven by inland rivers and flash flooding rather than the coast — FEMA's model puts a flood event here at about 2.1 times a year. County-wide, not parcel-specific: FEMA's real flood-zone map is queried live, never shipped as a download.
Mandatory flood insurance compliance in Winnebago County
25.2% of the homes FEMA requires to carry flood insurance in Winnebago County — those inside the mapped Special Flood Hazard Area — actually have a policy in force: 509 policies against 2,020 mandated structures, which means a meaningful share of legally-required coverage simply isn't there. Looking beyond the mandated zone, 0.6% of all residential structures in Winnebago County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
Winnebago County against the rest of the country
Among the 3144 US counties FEMA scores for flood hazard, Winnebago County ranks 193 — 1 being the highest hazard nationally — and 256 by population among all 3144 counties covered here, where 1 is the largest. About 283,790 people live in Winnebago County, Illinois, spread over 513.049 square miles.
What to do next if you own or are buying in Winnebago County
Across all of Winnebago County's 102,276 residential structures, 585 carry an NFIP policy today — a county-wide count that still can't tell you one address's own mapped zone.
Where Winnebago 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.