Franklin County, MA: flood risk, in FEMA's own numbers
On FEMA's National Risk Index, Franklin County scores at the 73.5th percentile for flood hazard, rated "Relatively Moderate" — a middling flood hazard by national standards. The hazard here is driven by inland rivers and flash flooding rather than the coast — FEMA's model puts a flood event here at about 1.6 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 Franklin County
FEMA hasn't published a residential structure count for Franklin County's mapped flood zone, so a reliable mandatory-compliance percentage can't be computed here — see the data quality guide for why this gap exists for roughly a quarter of US counties. Looking beyond the mandated zone, 0.7% of all residential structures in Franklin County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
How Franklin County compares nationally
Among the 3144 US counties FEMA scores for flood hazard, Franklin County ranks 871 — 1 being the highest hazard nationally — and 780 by population among all 3144 counties covered here, where 1 is the largest. Franklin County, Massachusetts covers 699.209 square miles and counts roughly 70,871 residents.
What to do next if you own or are buying in Franklin County
146 of Franklin County's 21,928 residential structures carry flood coverage of some kind, per FEMA's latest count — useful context, not a substitute for checking one parcel.
Where Franklin County's figures come from
Every figure on this page traces to a named FEMA dataset, documented in the methodology guide. Franklin County's compliance figure is one of the ones affected by FEMA's incomplete denominator data — the data quality guide explains what that means and how many counties it touches.