Knox County, IL flood risk explained
Flood hazard in Knox County sits at the 49.4th national percentile, below 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 1.4 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
Homes with a federally backed mortgage inside Knox County's mapped high-risk flood zone (the Special Flood Hazard Area, or SFHA) are legally required to carry an NFIP flood policy. In practice, 11.4% of them do — 16 active policies against 140 structures FEMA counts in that zone, leaving a real compliance gap. Looking beyond the mandated zone, 0.1% of all residential structures in Knox County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
How Knox County compares nationally
Among the 3144 US counties FEMA scores for flood hazard, Knox County ranks 1651 — 1 being the highest hazard nationally — and 1026 by population among all 3144 counties covered here, where 1 is the largest. Knox County, Illinois is home to about 48,716 people across 716.355 square miles of land.
Your street may differ from Knox County's average
Across all of Knox County's 20,693 residential structures, 29 carry an NFIP policy today — a county-wide count that still can't tell you one address's own mapped zone.
Where Knox 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.