Is Sullivan County, NH in a flood zone?
FEMA's National Risk Index puts Sullivan County's flood hazard at the 60.6th percentile nationally — below the national norm for flood hazard — driven by inland rivers and flash flooding rather than the coast — FEMA's model puts a flood event here at about 1.4 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.
Mandatory flood insurance compliance in Sullivan County
Homes with a federally backed mortgage inside Sullivan 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, 17.2% of them do — 64 active policies against 373 structures FEMA counts in that zone, leaving a real compliance gap. Across all residential structures in Sullivan County, not just the ones FEMA mandates, 0.7% 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 1296 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 1117 of 3144 by population (1 is biggest). Sullivan County, New Hampshire covers 537.882 square miles and counts roughly 44,012 residents.
Your street may differ from Sullivan County's average
FEMA counts 14,214 residential structures in Sullivan County overall, 92 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 Sullivan 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.