Johnson County, TN flood risk explained
Flood hazard in Johnson County sits at the 47.2th national percentile, 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 once every 1 years. That's a county-wide figure, not a per-address one — FEMA's parcel maps are a live lookup, not a bulk file.
Johnson County's flood-insurance compliance gap
Out of 351 homes FEMA counts inside Johnson County's mapped flood zone, 85 carry the flood policy federal law requires there — 24.2% compliance, short of full coverage. Looking beyond the mandated zone, 1.1% of all residential structures in Johnson County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
How Johnson County compares nationally
Among the 3144 US counties FEMA scores for flood hazard, Johnson County ranks 1721 — 1 being the highest hazard nationally — and 1905 by population among all 3144 counties covered here, where 1 is the largest. About 18,506 people live in Johnson County, Tennessee, spread over 298.44 square miles.
Checking a specific address in Johnson County
Across all of Johnson County's 9,382 residential structures, 104 carry an NFIP policy today — a county-wide count that still can't tell you one address's own mapped zone.
Where Johnson 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.