Walla Walla County, WA flood risk explained
Flood hazard in Walla Walla County sits at the 64.8th national percentile, below the national norm for flood hazard; 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. This describes the county, not any one street — FEMA only publishes exact parcel zones through a live map service.
Walla Walla County's flood-insurance compliance gap
FEMA hasn't published a residential structure count for Walla Walla 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, 0.7% of all residential structures in Walla Walla County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
Where Walla Walla County ranks
Among the 3144 US counties FEMA scores for flood hazard, Walla Walla County ranks 1155 — 1 being the highest hazard nationally — and 871 by population among all 3144 counties covered here, where 1 is the largest. About 62,068 people live in Walla Walla County, Washington, spread over 1,270.033 square miles.
Your street may differ from Walla Walla County's average
Across all of Walla Walla County's 20,900 residential structures, 145 carry an NFIP policy today — a county-wide count that still can't tell you one address's own mapped zone.
Where Walla Walla County's figures come from
Every figure on this page traces to a named FEMA dataset, documented in the methodology guide. Walla Walla 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.