Walworth County, SD flood risk explained
Flood hazard in Walworth County sits at the 34.8th 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 2 years. That's a county-wide figure, not a per-address one — FEMA's parcel maps are a live lookup, not a bulk file.
Who actually carries the flood insurance FEMA requires
FEMA hasn't published a residential structure count for Walworth 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 Walworth County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
How Walworth County compares nationally
Among the 3144 US counties FEMA scores for flood hazard, Walworth County ranks 2112 — 1 being the highest hazard nationally — and 2799 by population among all 3144 counties covered here, where 1 is the largest. Walworth County, South Dakota is home to about 5,270 people across 707.455 square miles of land.
Your street may differ from Walworth County's average
1 of Walworth County's 2,486 residential structures carry flood coverage of some kind, per FEMA's latest count — useful context, not a substitute for checking one parcel.
Where Walworth County's figures come from
Every figure on this page traces to a named FEMA dataset, documented in the methodology guide. Walworth 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.