How much flood risk does Union County actually carry?
Union County lands at the 38.9th percentile of FEMA's National Risk Index for flooding, "Relatively Low" territory — below the national norm for flood hazard — with the hazard driven by inland rivers and flash flooding rather than the coast — FEMA's model puts a flood event here at about 2.3 times a year. This describes the county, not any one street — FEMA only publishes exact parcel zones through a live map service.
Who actually carries the flood insurance FEMA requires
Out of 399 homes FEMA counts inside Union County's mapped flood zone, 44 carry the flood policy federal law requires there — 11% compliance, short of full coverage. Across all residential structures in Union County, not just the ones FEMA mandates, 0.9% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
Where Union County ranks
Union County sits at rank 1984 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 1984 of 3144 by population (1 is biggest). About 16,886 people live in Union County, Illinois, spread over 413.412 square miles.
Checking a specific address in Union County
FEMA counts 5,173 residential structures in Union County overall, 46 of them carrying some form of NFIP coverage — but a lender or insurer cares about one parcel, not that county total.
More on how this number was built
The methodology guide shows exactly which FEMA and Census tables feed Union 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.