Hampden County, MA: flood risk, in FEMA's own numbers
On FEMA's National Risk Index, Hampden County scores at the 95.9th percentile for flood hazard, rated "Relatively High" — well above the national norm for flood hazard. 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 2.8 times a year. This describes the county, not any one street — FEMA only publishes exact parcel zones through a live map service.
Hampden County's flood-insurance compliance gap
Homes with a federally backed mortgage inside Hampden 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, 26% of them do — 294 active policies against 1,130 structures FEMA counts in that zone, leaving a real compliance gap. Looking beyond the mandated zone, 0.4% of all residential structures in Hampden County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
How Hampden County compares nationally
Among the 3144 US counties FEMA scores for flood hazard, Hampden County ranks 139 — 1 being the highest hazard nationally — and 159 by population among all 3144 counties covered here, where 1 is the largest. Hampden County, Massachusetts is home to about 464,151 people across 617.006 square miles of land.
What to do next if you own or are buying in Hampden County
Across all of Hampden County's 116,062 residential structures, 496 carry an NFIP policy today — a county-wide count that still can't tell you one address's own mapped zone.
Where Hampden County's figures come from
Every figure on this page traces to a named FEMA dataset, documented in the methodology guide. If you're unsure why any of this insurance requirement exists at all, the SFHA explainer covers it from first principles.