How much flood risk does Mercer County actually carry?
Mercer County lands at the 16.4th percentile of FEMA's National Risk Index for flooding, "Very Low" territory — among the lowest flood hazard in the country — 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 Mercer County
Out of 346 homes FEMA counts inside Mercer County's mapped flood zone, 59 carry the flood policy federal law requires there — 17.1% compliance, short of full coverage. Across all residential structures in Mercer County, not just the ones FEMA mandates, 1.7% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
Where Mercer County ranks
Mercer County sits at rank 2661 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 2551 of 3144 by population (1 is biggest). About 8,348 people live in Mercer County, North Dakota, spread over 1,042.782 square miles.
What to do next if you own or are buying in Mercer County
Across all of Mercer County's 3,787 residential structures, 65 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 Mercer 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.