Marshall County, IL flood risk explained
Flood hazard in Marshall County sits at the 35.1th 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 times a year. This describes the county, not any one street — FEMA only publishes exact parcel zones through a live map service.
Marshall County's flood-insurance compliance gap
Homes with a federally backed mortgage inside Marshall 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, 20.9% of them do — 19 active policies against 91 structures FEMA counts in that zone, leaving a real compliance gap. Looking beyond the mandated zone, 0.4% of all residential structures in Marshall County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
How Marshall County compares nationally
Among the 3144 US counties FEMA scores for flood hazard, Marshall County ranks 2104 — 1 being the highest hazard nationally — and 2312 by population among all 3144 counties covered here, where 1 is the largest. About 11,552 people live in Marshall County, Illinois, spread over 386.822 square miles.
What to do next if you own or are buying in Marshall County
FEMA counts 5,782 residential structures in Marshall County overall, 22 of them carrying some form of NFIP coverage — but a lender or insurer cares about one parcel, not that county total.
Where Marshall 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.