Is Washtenaw County, MI in a flood zone?
FEMA's National Risk Index puts Washtenaw County's flood hazard at the 90.3th 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 1.2 times a year. That's a county-wide figure, not a per-address one — FEMA's parcel maps are a live lookup, not a bulk file.
Washtenaw County's flood-insurance compliance gap
Out of 799 homes FEMA counts inside Washtenaw County's mapped flood zone, 196 carry the flood policy federal law requires there — 24.5% compliance, short of full coverage. Across all residential structures in Washtenaw 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.
Washtenaw County against the rest of the country
Washtenaw County sits at rank 322 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 207 of 3144 by population (1 is biggest). About 373,875 people live in Washtenaw County, Michigan, spread over 706.015 square miles.
Your street may differ from Washtenaw County's average
FEMA counts 111,497 residential structures in Washtenaw County overall, 416 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 Washtenaw 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.