133 flood insurance claims·$1.6M paid·1 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 Washtenaw County, Michigan. 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.
Over the last thirty years, flood risk in Washtenaw County has been primarily defined by riverine flooding and flash flooding, with 21 general flood events and 17 flash flood events recorded by the NOAA Storm Events Database. Severe regional weather patterns have driven significant high-water events, such as the heavy thunderstorms in August 2023 that produced rainfall totals of 3 to 5 inches across the Detroit metro area, and the active weather pattern in June 2021 that dropped widespread rainfall of 3 to 5 inches with localized amounts of 6 to 8 inches.
National Flood Insurance Program records indicate that claims occur across multiple flood zones. Zone A leads the claim history with 87 filed claims, averaging a payout of $23,259 and an average recorded water depth of 9 inches. Meanwhile, Zone X has accounted for 34 claims with an average payout of $16,275 and an average recorded water depth of 5 inches. Smaller numbers of claims are recorded in Zone X_UNSHADED (6 claims averaging $17,019 and an average water depth of 1 inch) and Zone UNKNOWN (6 claims averaging $1,542 and an average water depth of 1 inch).
Homeowners and real estate professionals with properties located in FEMA Zone A should pay the closest attention to flood risk, given its higher frequency of claims, larger average payouts, and deeper average water depths compared to other zones in the county.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
6% of Washtenaw County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
93 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 7 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 2011, with 19 claims and $228,372 paid.
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.
13 NOAA storm reports from Washtenaw County describe what happened, in the words of the forecasters who covered it. Read the Michigan flood stories →
11 federal disaster declarations since 1965, 1 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Storms, Flooding, And Tornadoes | Jun 25, 2021 |
| Hurricane Katrina Evacuation | Aug 29, 2005 |
| Severe Storms, Tornadoes, And Flooding | May 20, 2004 |
| Power Outage | Aug 14, 2003 |
| Snow | Dec 11, 2000 |
| Mi - Severe Weather 1/2 /99 | Jan 2, 1999 |
| Severe Storms & Flooding | Sep 8, 1980 |
| Blizzards & Snowstorms | Jan 27, 1978 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
38 since 1996: 17 flash floods and 21 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | Jul 30, 2025 | — |
| Flood | Aug 24, 2023 | — |
| Flash Flood | Aug 24, 2023 | — |
| Flood | Jun 26, 2021 | — |
| Flash Flood | Jun 25, 2021 | $7.5M |
| Flood | Jan 11, 2020 | — |
| Flash Flood | Jul 30, 2016 | $40,000 |
| Flash Flood | Jun 14, 2015 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flash Flood · Jul 30, 2025. Heavy rain, 1.5 to 3 inches, produced flooding in and around Ypsilanti, Canton, and Northville.
Flood · Aug 24, 2023. Thunderstorms producing torrential rainfall led to flooding in the Detroit metro area early Thursday morning (August 24th). Western Wayne county into Monroe county was hardest hit resulting in widespread residential flooding, road closures, and stranded vehicles. Most notable was the closure of Dingell Drive at Detroit Metro Airport which cut off access to the McNamara terminal for several hours. A lengthy closure…
Flash Flood · Aug 24, 2023. Thunderstorms producing torrential rainfall led to flooding in the Detroit metro area early Thursday morning (August 24th). Western Wayne county into Monroe county was hardest hit resulting in widespread residential flooding, road closures, and stranded vehicles. Most notable was the closure of Dingell Drive at Detroit Metro Airport which cut off access to the McNamara terminal for several hours. A lengthy closure…
Flood · Jun 26, 2021. After several weeks of moderate to severe drought conditions in Southeast Michigan, an active weather pattern brought widespread rainfall and flooding to Metro Detroit and surrounding areas during the weekend of June 25-27th. Low pressure tracking along a stalled stationary boundary interacted with a very moist subtropical air mass to produce widespread 3 to 5 inches of rainfall across Metro Detroit (localized 6 t…
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 Washtenaw 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.