How much flood risk does Franklin County actually carry?
Franklin County lands at the 98.8th percentile of FEMA's National Risk Index for flooding, "Relatively High" territory — well above the national norm for flood hazard — with the hazard driven by inland rivers and flash flooding rather than the coast — FEMA's model puts a flood event here at about 3.5 times a year. This describes the county, not any one street — FEMA only publishes exact parcel zones through a live map service.
Who actually carries the flood insurance FEMA requires
Out of 4,209 homes FEMA counts inside Franklin County's mapped flood zone, 707 carry the flood policy federal law requires there — 16.8% compliance, short of full coverage. Across all residential structures in Franklin County, not just the ones FEMA mandates, 0.3% 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 43 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 32 of 3144 by population (1 is biggest). Franklin County, Ohio is home to about 1,356,303 people across 532.417 square miles of land.
Checking a specific address in Franklin County
Across all of Franklin County's 388,712 residential structures, 1,221 carry an NFIP policy today — a county-wide count that still can't tell you one address's own mapped zone.
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.