How much flood risk does Clayton County actually carry?
Clayton County lands at the 87.8th 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 once every 2 years. That's a county-wide figure, not a per-address one — FEMA's parcel maps are a live lookup, not a bulk file.
Who actually carries the flood insurance FEMA requires
Homes with a federally backed mortgage inside Clayton 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, 22.4% of them do — 199 active policies against 889 structures FEMA counts in that zone, leaving a real compliance gap. Across all residential structures in Clayton 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.
How Clayton County compares nationally
Clayton County sits at rank 402 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 247 of 3144 by population (1 is biggest). Clayton County, Georgia is home to about 297,703 people across 141.703 square miles of land.
Your street may differ from Clayton County's average
Across all of Clayton County's 84,297 residential structures, 312 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 Clayton 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.