How much flood risk does Marion County actually carry?
Marion County lands at the 55.5th percentile of FEMA's National Risk Index for flooding, "Relatively Low" territory — below 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 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.
Marion County's flood-insurance compliance gap
Out of 1,016 homes FEMA counts inside Marion County's mapped flood zone, 179 carry the flood policy federal law requires there — 17.6% compliance, short of full coverage. Across all residential structures in Marion County, not just the ones FEMA mandates, 2% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
Marion County against the rest of the country
Marion County sits at rank 1463 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 1495 of 3144 by population (1 is biggest). About 28,368 people live in Marion County, South Carolina, spread over 489.372 square miles.
What to do next if you own or are buying in Marion County
277 of Marion County's 13,698 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 Marion 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.