Will County, IL: flood risk, in FEMA's own numbers
On FEMA's National Risk Index, Will County scores at the 97.9th percentile for flood hazard, rated "Relatively High" — well above the national norm for flood hazard. 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 3 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 Will County
Homes with a federally backed mortgage inside Will 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, 22.7% of them do — 747 active policies against 3,291 structures FEMA counts in that zone, leaving a real compliance gap. Looking beyond the mandated zone, 0.5% of all residential structures in Will County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
Will County against the rest of the country
Among the 3144 US counties FEMA scores for flood hazard, Will County ranks 73 — 1 being the highest hazard nationally — and 99 by population among all 3144 counties covered here, where 1 is the largest. Will County, Illinois covers 835.908 square miles and counts roughly 708,583 residents.
Your street may differ from Will County's average
Across all of Will County's 220,472 residential structures, 1,026 carry an NFIP policy today — a county-wide count that still can't tell you one address's own mapped zone.
Where Will 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.