How much flood risk does Franklin County actually carry?
Franklin County lands at the 84.3th 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 1.9 times a year. This describes the county, not any one street — FEMA only publishes exact parcel zones through a live map service.
Franklin County's flood-insurance compliance gap
Homes with a federally backed mortgage inside Franklin 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, 20.1% of them do — 156 active policies against 777 structures FEMA counts in that zone, leaving a real compliance gap. Across all residential structures in Franklin County, not just the ones FEMA mandates, 0.4% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
Where Franklin County ranks
Franklin County sits at rank 517 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 440 of 3144 by population (1 is biggest). Franklin County, Pennsylvania is home to about 159,285 people across 772.279 square miles of land.
What to do next if you own or are buying in Franklin County
FEMA counts 59,690 residential structures in Franklin County overall, 213 of them carrying some form of NFIP coverage — but a lender or insurer cares about one parcel, not that county total.
More on how this number was built
The methodology guide shows exactly which FEMA and Census tables feed Franklin 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.