How much flood risk does Sussex County actually carry?
Sussex County lands at the 97.6th percentile of FEMA's National Risk Index for flooding, "Very High" territory — among the highest flood hazard in the country — with the hazard split between inland river flooding (about 2.5 times a year) and coastal storm surge (about 3.7 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
61.4% of the homes FEMA requires to carry flood insurance in Sussex County — those inside the mapped Special Flood Hazard Area — actually have a policy in force: 10,708 policies against 17,440 mandated structures, which means a meaningful share of legally-required coverage simply isn't there. Across all residential structures in Sussex County, not just the ones FEMA mandates, 12.7% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
Where Sussex County ranks
Sussex County sits at rank 87 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 270 of 3144 by population (1 is biggest). Sussex County, Delaware covers 936.146 square miles and counts roughly 271,134 residents.
Your street may differ from Sussex County's average
15,126 of Sussex County's 119,460 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 Sussex County's numbers. Because storm surge plays a real role here, the guide to coastal vs. inland flood hazard is worth reading alongside this page.