Jersey County, IL: flood risk, in FEMA's own numbers
On FEMA's National Risk Index, Jersey County scores at the 18th percentile for flood hazard, rated "Very Low" — among the lowest flood hazard in the country. 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 1.1 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.
Jersey County's flood-insurance compliance gap
28.4% of the homes FEMA requires to carry flood insurance in Jersey County — those inside the mapped Special Flood Hazard Area — actually have a policy in force: 61 policies against 215 mandated structures, which means a meaningful share of legally-required coverage simply isn't there. Looking beyond the mandated zone, 0.9% of all residential structures in Jersey County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
How Jersey County compares nationally
Among the 3144 US counties FEMA scores for flood hazard, Jersey County ranks 2615 — 1 being the highest hazard nationally — and 1763 by population among all 3144 counties covered here, where 1 is the largest. Jersey County, Illinois covers 369.556 square miles and counts roughly 21,150 residents.
Checking a specific address in Jersey County
72 of Jersey County's 8,152 residential structures carry flood coverage of some kind, per FEMA's latest count — useful context, not a substitute for checking one parcel.
Where Jersey 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.