How much flood risk does Kane County actually carry?
Kane County lands at the 95.5th percentile of FEMA's National Risk Index for flooding, "Relatively High" territory — well above 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 1.8 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 Kane County
Homes with a federally backed mortgage inside Kane 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, 28% of them do — 410 active policies against 1,465 structures FEMA counts in that zone, leaving a real compliance gap. Across all residential structures in Kane County, not just the ones FEMA mandates, 0.4% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
Kane County against the rest of the country
Kane County sits at rank 155 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 143 of 3144 by population (1 is biggest). Kane County, Illinois covers 519.361 square miles and counts roughly 520,997 residents.
Your street may differ from Kane County's average
Across all of Kane County's 145,597 residential structures, 634 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 Kane 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.