How much flood risk does Harrison County actually carry?
Harrison County lands at the 37th 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 1 years. County-wide, not parcel-specific: FEMA's real flood-zone map is queried live, never shipped as a download.
Harrison County's flood-insurance compliance gap
14.2% of the homes FEMA requires to carry flood insurance in Harrison County — those inside the mapped Special Flood Hazard Area — actually have a policy in force: 159 policies against 1,121 mandated structures, which means a meaningful share of legally-required coverage simply isn't there. Across all residential structures in Harrison 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.
Where Harrison County ranks
Harrison County sits at rank 2046 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 2115 of 3144 by population (1 is biggest). About 14,626 people live in Harrison County, Iowa, spread over 696.874 square miles.
Your street may differ from Harrison County's average
177 of Harrison County's 8,748 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 Harrison 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.