How much flood risk does Sullivan County actually carry?
Sullivan County lands at the 12.4th 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 3 years. That's a county-wide figure, not a per-address one — FEMA's parcel maps are a live lookup, not a bulk file.
Who actually carries the flood insurance FEMA requires
Sullivan County is one of the counties where FEMA's own denominator for mandated flood-zone structures is missing, so no compliance rate is shown rather than a guessed one — the data quality guide covers how common this is. Across all residential structures in Sullivan County, not just the ones FEMA mandates, 0% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
Where Sullivan County ranks
Sullivan County sits at rank 2778 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 2757 of 3144 by population (1 is biggest). Sullivan County, Missouri is home to about 5,750 people across 647.982 square miles of land.
Your street may differ from Sullivan County's average
Across all of Sullivan County's 2,819 residential structures, 0 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 Sullivan County's numbers. See the data quality guide for why Sullivan County, like hundreds of other counties, doesn't get a clean compliance percentage.