Enter any address in Waukesha County, Wisconsin to see its FEMA flood zone
Flash flooding from intense thunderstorms is the dominant flood character in Waukesha County. Between 2000 and 2020, the NOAA Storm Events Database recorded 36 flash flood events and 25 flood events, with flash flooding resulting in 3 fatalities. For example, a historic flash flood event in August 2025 brought record rainfall and widespread flooding to streets, creeks, and low-lying neighborhoods across Southeast Wisconsin, causing damages in the hundreds of millions.
National Flood Insurance Program (NFIP) claims data shows that properties in Zone A have experienced the most claims, with an average payout of $27,451 and an average water depth of 4.6 feet. Properties in Zone X and Zone X_Unshaded also show significant claim activity. Homeowners in Zone A, as well as those in other flood zones or located near creeks and rivers, should pay close attention to flood risk.
Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.
44 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
Waukesha County, Wisconsin has recorded 61 flood-related events since 1996 according to NOAA's Storm Events Database, including 36 flash floods and 25 river or area floods. The county has received 18 federal disaster declarations, 6 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.
FEMA Disaster Declarations (1969–2025)
Source: OpenFEMA Disaster Declarations Summaries.
| Declaration | Type | Date |
|---|---|---|
| Severe Storms, Straight-line Winds, Flooding, And Mudslides | Flood | Aug 9, 2025 |
| Covid-19 | Biological | Jan 20, 2020 |
| Covid-19 Pandemic | Biological | Jan 20, 2020 |
| Severe Storms, Tornadoes, And Flooding | Severe Storm | Jun 5, 2008 |
| Record Snow And Near Record Snow | Snowstorm | Feb 5, 2008 |
| Hurricane Katrina Evacuation | Hurricane | Aug 29, 2005 |
| Severe Storms And Flooding | Severe Storm | May 7, 2004 |
| Snow | Snowstorm | Dec 11, 2000 |
| Severe Storms, Tornadoes, And Flooding | Severe Storm | May 26, 2000 |
| Severe Storms And Flooding | Severe Storm | Aug 5, 1998 |
NOAA Storm Events Database (1996–2025)
Source: NOAA National Weather Service Storm Events Database.
| Type | Date | Damage |
|---|---|---|
| Flash Flood | Aug 10, 2025 | 1.00K |
| Flood | Aug 10, 2025 | 1.00M |
| Flash Flood | Aug 9, 2025 | 9.00M |
| Flash Flood | Aug 9, 2025 | 89.00M |
| Flood | Aug 14, 2023 | 1.00K |
| Flood | Jun 15, 2022 | 1.00K |
| Flood | Sep 11, 2022 | 25.00K |
| Flood | Jun 10, 2022 | 30.00K |
| Flood | May 17, 2020 | 15.00K |
| Flood | Mar 13, 2019 | 2.00K |
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...
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...
Flash Flood — Aug 9, 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...
Flood — Aug 14, 2023
A slow moving, strong low pressure area brought several hours of moderate to heavy rainfall to southern WI. Street flooding occurred in urban areas.
Flood — Jun 15, 2022
A severe squall line formed along a surface trough and brought numerous swaths of wind damage to southern WI. Tree damage was prevalent and some structural damage occurred. The line of storms also slowed down, causing sporadic street flooding. Two home fires occurred after being struck by lightning.
Source: NOAA National Weather Service Storm Events Database.
Source: OpenFEMA NFIP Individual Claims (2.25M records analyzed).
FEMA assigns flood zone designations to areas in Waukesha County, Wisconsin:
AE High Risk — 1% annual chance of flooding. Insurance required.
VE Very High Risk — Coastal flooding with wave action.
X (Shaded) Moderate Risk — 500-year floodplain.
X Low Risk — Outside major floodplains.
Properties in Waukesha County, Wisconsin that are in FEMA-designated Special Flood Hazard Areas (zones A and V) with federally backed mortgages are required to carry flood insurance.
Even outside high-risk zones, flood insurance is recommended. From 2014 to 2024, nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area.
Visit FloodSmart.gov to find an agent and get a quote.