Washington County, OR flood risk explained
Flood hazard in Washington County sits at the 93.9th national percentile, well above 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 1 years. That's a county-wide figure, not a per-address one — FEMA's parcel maps are a live lookup, not a bulk file.
Washington County's flood-insurance compliance gap
38.1% of the homes FEMA requires to carry flood insurance in Washington County — those inside the mapped Special Flood Hazard Area — actually have a policy in force: 673 policies against 1,766 mandated structures, which means a meaningful share of legally-required coverage simply isn't there. Looking beyond the mandated zone, 0.6% of all residential structures in Washington County carry flood coverage voluntarily or otherwise — relevant because most NFIP claims nationally come from outside the mapped SFHA.
Where Washington County ranks
Among the 3144 US counties FEMA scores for flood hazard, Washington County ranks 210 — 1 being the highest hazard nationally — and 114 by population among all 3144 counties covered here, where 1 is the largest. Washington County, Oregon covers 724.272 square miles and counts roughly 611,272 residents.
Your street may differ from Washington County's average
FEMA counts 176,868 residential structures in Washington County overall, 1,044 of them carrying some form of NFIP coverage — but a lender or insurer cares about one parcel, not that county total.
Where Washington County's figures come from
Every figure on this page traces to a named FEMA dataset, documented in the methodology guide. If you're unsure why any of this insurance requirement exists at all, the SFHA explainer covers it from first principles.