Sangamon County, IL: flood risk, in FEMA's own numbers
On FEMA's National Risk Index, Sangamon County scores at the 91.2th percentile for flood hazard, rated "Relatively Moderate" — a middling flood hazard by national standards. 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 2.2 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.
Sangamon County's flood-insurance compliance gap
Homes with a federally backed mortgage inside Sangamon 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, 18.7% of them do — 68 active policies against 363 structures FEMA counts in that zone, leaving a real compliance gap. Looking beyond the mandated zone, 0.2% of all residential structures in Sangamon County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
Sangamon County against the rest of the country
Among the 3144 US counties FEMA scores for flood hazard, Sangamon County ranks 295 — 1 being the highest hazard nationally — and 366 by population among all 3144 counties covered here, where 1 is the largest. Sangamon County, Illinois covers 868.23 square miles and counts roughly 194,345 residents.
Checking a specific address in Sangamon County
167 of Sangamon County's 73,774 residential structures carry flood coverage of some kind, per FEMA's latest count — useful context, not a substitute for checking one parcel.
Where Sangamon 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.