Cassia County, ID: flood risk, in FEMA's own numbers
On FEMA's National Risk Index, Cassia County scores at the 52.7th percentile for flood hazard, rated "Relatively Low" — below 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 once every 1 years. County-wide, not parcel-specific: FEMA's real flood-zone map is queried live, never shipped as a download.
Who actually carries the flood insurance FEMA requires
FEMA hasn't published a residential structure count for Cassia 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, 0.2% of all residential structures in Cassia County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
Where Cassia County ranks
Among the 3144 US counties FEMA scores for flood hazard, Cassia County ranks 1549 — 1 being the highest hazard nationally — and 1584 by population among all 3144 counties covered here, where 1 is the largest. Cassia County, Idaho is home to about 25,976 people across 2,565.61 square miles of land.
What to do next if you own or are buying in Cassia County
Across all of Cassia County's 8,308 residential structures, 17 carry an NFIP policy today — a county-wide count that still can't tell you one address's own mapped zone.
Where Cassia County's figures come from
Every figure on this page traces to a named FEMA dataset, documented in the methodology guide. Cassia 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.