Dorchester County, SC flood risk explained
Flood hazard in Dorchester County sits at the 78.7th national percentile, a middling flood hazard by national standards; driven by inland rivers and flash flooding rather than the coast — FEMA's model puts a flood event here at about 1.4 times a year. This describes the county, not any one street — FEMA only publishes exact parcel zones through a live map service.
Dorchester County's flood-insurance compliance gap
71% of the homes FEMA requires to carry flood insurance in Dorchester County — those inside the mapped Special Flood Hazard Area — actually have a policy in force: 1,246 policies against 1,754 mandated structures, which means a meaningful share of legally-required coverage simply isn't there. Looking beyond the mandated zone, 5% of all residential structures in Dorchester County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
How Dorchester County compares nationally
Among the 3144 US counties FEMA scores for flood hazard, Dorchester County ranks 699 — 1 being the highest hazard nationally — and 399 by population among all 3144 counties covered here, where 1 is the largest. Dorchester County, South Carolina covers 568.393 square miles and counts roughly 174,663 residents.
Checking a specific address in Dorchester County
FEMA counts 54,797 residential structures in Dorchester County overall, 2,718 of them carrying some form of NFIP coverage — but a lender or insurer cares about one parcel, not that county total.
Where Dorchester County's figures come from
Every figure on this page traces to a named FEMA dataset, documented in the methodology guide. If you're unsure why any of this insurance requirement exists at all, the SFHA explainer covers it from first principles.