How much flood risk does Fond du Lac County actually carry?
Fond du Lac County lands at the 74.3th percentile of FEMA's National Risk Index for flooding, "Relatively Moderate" territory — a middling flood hazard by national standards — 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 2 years. This describes the county, not any one street — FEMA only publishes exact parcel zones through a live map service.
Fond du Lac County's flood-insurance compliance gap
Homes with a federally backed mortgage inside Fond du Lac 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, 18.5% of them do — 341 active policies against 1,844 structures FEMA counts in that zone, leaving a real compliance gap. Across all residential structures in Fond du Lac County, not just the ones FEMA mandates, 1.1% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
How Fond du Lac County compares nationally
Fond du Lac County sits at rank 844 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 601 of 3144 by population (1 is biggest). Fond du Lac County, Wisconsin covers 719.566 square miles and counts roughly 104,269 residents.
What to do next if you own or are buying in Fond du Lac County
Across all of Fond du Lac County's 38,060 residential structures, 415 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 Fond du Lac 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.