How much flood risk does Lyon County actually carry?
Lyon County lands at the 49.3th percentile of FEMA's National Risk Index for flooding, "Relatively Low" territory — below the national norm for flood hazard — with the hazard driven by inland rivers and flash flooding rather than the coast — FEMA's model puts a flood event here at about 2.3 times a year. County-wide, not parcel-specific: FEMA's real flood-zone map is queried live, never shipped as a download.
Lyon County's flood-insurance compliance gap
5.1% of the homes FEMA requires to carry flood insurance in Lyon County — those inside the mapped Special Flood Hazard Area — actually have a policy in force: 18 policies against 352 mandated structures, which means a meaningful share of legally-required coverage simply isn't there. Across all residential structures in Lyon County, not just the ones FEMA mandates, 0.3% carry an NFIP policy — most flood damage nationally happens outside the mapped high-risk zone, so that broader number matters too.
How Lyon County compares nationally
Lyon County sits at rank 1654 of 3144 counties on FEMA's flood hazard scale (1 is worst) and rank 1381 of 3144 by population (1 is biggest). Lyon County, Kansas covers 847.477 square miles and counts roughly 32,520 residents.
Your street may differ from Lyon County's average
35 of Lyon County's 12,894 residential structures carry flood coverage of some kind, per FEMA's latest count — useful context, not a substitute for checking one parcel.
More on how this number was built
The methodology guide shows exactly which FEMA and Census tables feed Lyon County's numbers. The guide to what the Special Flood Hazard Area actually means explains why the mandatory-insurance rule exists and who it applies to.