Washington County, IL flood risk explained
Flood hazard in Washington County sits at the 39th 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 once every 2 years. This describes the county, not any one street — FEMA only publishes exact parcel zones through a live map service.
Mandatory flood insurance compliance in Washington County
FEMA hasn't published a residential structure count for Washington County's mapped flood zone, so a reliable mandatory-compliance percentage can't be computed here — see the data quality guide for why this gap exists for roughly a quarter of US counties. Looking beyond the mandated zone, 0.1% of all residential structures in Washington County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
Washington County against the rest of the country
Among the 3144 US counties FEMA scores for flood hazard, Washington County ranks 1980 — 1 being the highest hazard nationally — and 2186 by population among all 3144 counties covered here, where 1 is the largest. Washington County, Illinois is home to about 13,535 people across 562.597 square miles of land.
What to do next if you own or are buying in Washington County
6 of Washington County's 8,543 residential structures carry flood coverage of some kind, per FEMA's latest count — useful context, not a substitute for checking one parcel.
Where Washington County's figures come from
Every figure on this page traces to a named FEMA dataset, documented in the methodology guide. Washington County's compliance figure is one of the ones affected by FEMA's incomplete denominator data — the data quality guide explains what that means and how many counties it touches.