Union County, NJ: flood risk, in FEMA's own numbers
On FEMA's National Risk Index, Union County scores at the 97.5th 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 3.4 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 Union County
Homes with a federally backed mortgage inside Union 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, 49.2% of them do — 2,400 active policies against 4,874 structures FEMA counts in that zone, leaving a real compliance gap. Looking beyond the mandated zone, 2.9% of all residential structures in Union County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
Union County against the rest of the country
Among the 3144 US counties FEMA scores for flood hazard, Union County ranks 90 — 1 being the highest hazard nationally — and 118 by population among all 3144 counties covered here, where 1 is the largest. Union County, New Jersey covers 102.767 square miles and counts roughly 594,160 residents.
Your street may differ from Union County's average
FEMA counts 124,053 residential structures in Union County overall, 3,566 of them carrying some form of NFIP coverage — but a lender or insurer cares about one parcel, not that county total.
Where Union 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.