78 flood insurance claims·$1.2M paid·3 federal flood & hurricane disasters
Share of the whole county outline, rivers and lakes included; parts FEMA hasn’t mapped count as zero.
Shaded areas are FEMA’s mapped flood hazard zones in and around Washington County, Wisconsin. Zoomed out they are simplified; at street level the map switches to FEMA’s exact layer. Tap anywhere to check that spot, or search an address above.
Flash flooding and general flooding events from summer thunderstorms dominate the flood character of Washington County, Wisconsin. Over the past 30 years, the NOAA Storm Events Database recorded 12 flash flood events and 11 flood events, which resulted in 1 death. A notable historic flash flood and record rainfall occurred in August 2025, producing more than 10 inches of rain from numerous thunderstorms along a stalled front, causing widespread flooding of streets, creeks, rivers, and low-lying neighborhoods across portions of the Milwaukee Metropolitan Area and Southeast Wisconsin with damages in the hundreds of millions of dollars.
National Flood Insurance Program claims data demonstrate that flood risks extend across multiple zones. Zone A accounts for the highest volume with 55 claims, featuring an average payout of $17,275 and an average recorded water depth of 4 inches. Properties located in Zone X experienced higher average severity with 11 claims averaging a $77,244 payout and an average recorded water depth of 3 inches. Additional claims occurred in Zone X_SHADED (2 claims, average payout of $14,658, average water depth of 6 inches), Zone X_UNSHADED (6 claims, average payout of $6,868, average water depth of 0 inches), and Zone UNKNOWN (4 claims, average payout of $99, average water depth of 1 inch). Homeowners and real estate agents managing properties in Zone A and Zone X should pay the closest attention to these historical claim patterns and flood risks.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
13% of Washington County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
63 NFIP claims with a recorded rated flood zone, 1978 to date. The zone is the one FEMA used to rate that policy, which may not match today’s map. Source: OpenFEMA NFIP claims.
In flood insurance claims here that reported a flood depth, the average was 4 inches.
Drawn to scale against an 80-inch door. Even a few inches soaks flooring, the bottom of the drywall and anything plugged in near the floor.
Average of the depths reported on claims (zero and implausible values left out); FEMA’s record doesn’t say exactly where each depth was measured. Source: OpenFEMA NFIP claims.
The worst year was 2008, with 26 claims and $416,758 paid, the year of Severe Storms, Tornadoes, and Flooding.
Bar height is scaled by square root so ordinary years stay visible next to the worst one. NFIP claims by year of loss. Source: OpenFEMA.
19 NOAA storm reports from Washington County describe what happened, in the words of the forecasters who covered it. Read the Wisconsin flood stories →
13 federal disaster declarations since 1976, 3 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Storms, Straight-line Winds, Flooding, And Mudslides | Aug 9, 2025 |
| Severe Winter Storm And Snowstorm | Jan 31, 2011 |
| Severe Storms, Tornadoes, And Flooding | Jun 5, 2008 |
| Record Snow And Near Record Snow | Feb 5, 2008 |
| Hurricane Katrina Evacuation | Aug 29, 2005 |
| Severe Storms And Flooding | May 7, 2004 |
| Severe Storms And Flooding | Jun 21, 1997 |
| Severe Storms & Hail | Jul 7, 1991 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
23 since 1996: 12 flash floods and 11 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flood | Aug 10, 2025 | $1.0M · 1 killed |
| Flash Flood | Aug 10, 2025 | $2.4M |
| Flash Flood | Apr 19, 2023 | $20,000 |
| Flood | Aug 27, 2018 | $1,000 |
| Flash Flood | Aug 27, 2018 | $584,000 |
| Flood | Feb 20, 2018 | — |
| Flash Flood | Jul 22, 2010 | $20,000 |
| Flash Flood | Apr 25, 2008 | $10,000 |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flood · Aug 10, 2025. A historic flash flood and record rainfall occurred over portions of the Milwaukee Metropolitan Area and Southeast WI resulting in damages in the $100s Millions. Warm, moist, and unstable air rose along a stalled front to produce numerous thunderstorms and more than 10 inches of rain in many locations. Widespread flash flooding of streets, creeks, rivers, and low lying neighborhoods occurred. A homeless camp in Mi…
Flash Flood · Aug 10, 2025. A historic flash flood and record rainfall occurred over portions of the Milwaukee Metropolitan Area and Southeast WI resulting in damages in the $100s Millions. Warm, moist, and unstable air rose along a stalled front to produce numerous thunderstorms and more than 10 inches of rain in many locations. Widespread flash flooding of streets, creeks, rivers, and low lying neighborhoods occurred. A homeless camp in Mi…
Flash Flood · Apr 19, 2023. A surge of relatively mild, moist, and unstable air aloft brought rounds of strong to severe thunderstorms to southern WI. Numerous reports of large hail were received. Flash flooding and general flooding occurred in urban areas.
Flood · Aug 27, 2018. Multiple rounds of strong to severe thunderstorms moved across southern WI as a warm front slowly moved north through the region. Flash flooding occurred in Washington, Ozaukee, and northern Milwaukee Counties which was followed by prolonged river flooding. Four to eight inches of rain had fallen over this area. The thunderstorms produced sporadic tree and power line damage across southern WI.
National Weather Service narratives, lightly trimmed. Source: NOAA Storm Events Database.
Every colour on the map above is a place on this drawing: where the ground sits relative to the flood FEMA plans for.
If a building in Washington County is in a high-risk zone (A or V) and its mortgage comes from a federally regulated or insured lender, or is federally backed, flood insurance is required.
Outside those zones it is optional, and often worth having: from 2014 to 2024 nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area. Since Risk Rating 2.0, NFIP premiums are set for each building, so the only reliable price is a quote: FloodSmart.gov or a local agent.