How much flood risk does Prince William County actually carry?
Prince William County lands at the 88th percentile of FEMA's National Risk Index for flooding, "Relatively Moderate" territory — a middling flood hazard by national standards — with the hazard driven by inland rivers and flash flooding rather than the coast — FEMA's model puts a flood event here at about 3.4 times a year. This describes the county, not any one street — FEMA only publishes exact parcel zones through a live map service.
Prince William County's flood-insurance compliance gap
Out of 414 homes FEMA counts inside Prince William County's mapped flood zone, 192 carry the flood policy federal law requires there — 46.4% compliance, short of full coverage. Across all residential structures in Prince William County, not just the ones FEMA mandates, 1.3% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
Prince William County against the rest of the country
Prince William County sits at rank 395 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 150 of 3144 by population (1 is biggest). Prince William County, Virginia covers 335.264 square miles and counts roughly 497,003 residents.
Checking a specific address in Prince William County
935 of Prince William County's 73,041 residential structures carry flood coverage of some kind, per FEMA's latest count — useful context, not a substitute for checking one parcel.
More on how this number was built
The methodology guide shows exactly which FEMA and Census tables feed Prince William County's numbers. The guide to what the Special Flood Hazard Area actually means explains why the mandatory-insurance rule exists and who it applies to.