How much flood risk does Johnston County actually carry?
Johnston County lands at the 87.1th 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 1.6 times a year. This describes the county, not any one street — FEMA only publishes exact parcel zones through a live map service.
Johnston County's flood-insurance compliance gap
Out of 486 homes FEMA counts inside Johnston County's mapped flood zone, 173 carry the flood policy federal law requires there — 35.6% compliance, short of full coverage. Across all residential structures in Johnston County, not just the ones FEMA mandates, 0.7% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
How Johnston County compares nationally
Johnston County sits at rank 424 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 293 of 3144 by population (1 is biggest). About 249,794 people live in Johnston County, North Carolina, spread over 792.017 square miles.
What to do next if you own or are buying in Johnston County
489 of Johnston County's 74,158 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 Johnston 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.