Lewis County, ID flood risk explained
Flood hazard in Lewis County sits at the 12th 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 7 years. This describes the county, not any one street — FEMA only publishes exact parcel zones through a live map service.
Who actually carries the flood insurance FEMA requires
FEMA hasn't published a residential structure count for Lewis 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, 0.9% of all residential structures in Lewis County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
Where Lewis County ranks
Among the 3144 US counties FEMA scores for flood hazard, Lewis County ranks 2789 — 1 being the highest hazard nationally — and 2904 by population among all 3144 counties covered here, where 1 is the largest. Lewis County, Idaho is home to about 3,728 people across 478.822 square miles of land.
Checking a specific address in Lewis County
16 of Lewis County's 1,856 residential structures carry flood coverage of some kind, per FEMA's latest count — useful context, not a substitute for checking one parcel.
Where Lewis County's figures come from
Every figure on this page traces to a named FEMA dataset, documented in the methodology guide. Lewis 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.