How much flood risk does Portage County actually carry?
Portage County lands at the 66.8th 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 2 years. That's a county-wide figure, not a per-address one — FEMA's parcel maps are a live lookup, not a bulk file.
Mandatory flood insurance compliance in Portage County
Homes with a federally backed mortgage inside Portage 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, 9.2% of them do — 22 active policies against 239 structures FEMA counts in that zone, leaving a real compliance gap. Across all residential structures in Portage County, not just the ones FEMA mandates, 0.2% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
Where Portage County ranks
Portage County sits at rank 1089 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 769 of 3144 by population (1 is biggest). About 72,040 people live in Portage County, Wisconsin, spread over 800.874 square miles.
Checking a specific address in Portage County
FEMA counts 22,311 residential structures in Portage County overall, 45 of them carrying some form of NFIP coverage — but a lender or insurer cares about one parcel, not that county total.
More on how this number was built
The methodology guide shows exactly which FEMA and Census tables feed Portage 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.