Is Chester County, SC in a flood zone?
FEMA's National Risk Index puts Chester County's flood hazard at the 41.7th percentile nationally — below the national norm for flood hazard — driven by inland rivers and flash flooding rather than the coast — FEMA's model puts a flood event here at about once every 3 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
13.6% of the homes FEMA requires to carry flood insurance in Chester County — those inside the mapped Special Flood Hazard Area — actually have a policy in force: 15 policies against 110 mandated structures, which means a meaningful share of legally-required coverage simply isn't there. Across all residential structures in Chester County, not just the ones FEMA mandates, 0.2% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
How Chester County compares nationally
Chester County sits at rank 1894 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 1387 of 3144 by population (1 is biggest). About 32,323 people live in Chester County, South Carolina, spread over 580.865 square miles.
Your street may differ from Chester County's average
Across all of Chester County's 12,852 residential structures, 20 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 Chester 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.