Sioux County, NE flood risk explained
Flood hazard in Sioux County sits at the 1.7th national percentile, among the lowest flood hazard in the country; driven by inland rivers and flash flooding rather than the coast — FEMA's model puts a flood event here at about once every 5 years. County-wide, not parcel-specific: FEMA's real flood-zone map is queried live, never shipped as a download.
Sioux County's flood-insurance compliance gap
FEMA hasn't published a residential structure count for Sioux 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% of all residential structures in Sioux County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
Sioux County against the rest of the country
Among the 3144 US counties FEMA scores for flood hazard, Sioux County ranks 3097 — 1 being the highest hazard nationally — and 3105 by population among all 3144 counties covered here, where 1 is the largest. Sioux County, Nebraska covers 2,066.723 square miles and counts roughly 1,099 residents.
Checking a specific address in Sioux County
FEMA counts 1,607 residential structures in Sioux County overall, 0 of them carrying some form of NFIP coverage — but a lender or insurer cares about one parcel, not that county total.
Where Sioux County's figures come from
Every figure on this page traces to a named FEMA dataset, documented in the methodology guide. Sioux 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.