Is Delaware County, OH in a flood zone?
FEMA's National Risk Index puts Delaware County's flood hazard at the 86.4th percentile nationally — 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 1.7 times a year. This describes the county, not any one street — FEMA only publishes exact parcel zones through a live map service.
Mandatory flood insurance compliance in Delaware County
Homes with a federally backed mortgage inside Delaware 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, 15.6% of them do — 45 active policies against 288 structures FEMA counts in that zone, leaving a real compliance gap. Across all residential structures in Delaware County, not just the ones FEMA mandates, 0.3% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
How Delaware County compares nationally
Delaware County sits at rank 449 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 303 of 3144 by population (1 is biggest). Delaware County, Ohio is home to about 237,966 people across 443.149 square miles of land.
What to do next if you own or are buying in Delaware County
201 of Delaware County's 71,070 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 Delaware 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.