8 flood insurance claims·$174,306 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 Washington County, Illinois. 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 from heavy rainfall events dominates the flood character of Washington County, Illinois. Over the last 30 years, the NOAA Storm Events Database recorded 14 flash flood events compared to 4 general flood events. Recent activity includes training thunderstorms that produced up to 4 inches of rain in a short time in July 2021, and a stationary front that caused flash flooding across portions of southwest and south-central Illinois in April 2025.
Federal insurance records reflect these localized risks. In FEMA Zone A, the National Flood Insurance Program logged 7 claims with an average payout of $27,022 and an average recorded water depth of 2 inches. An additional claim was recorded in an unknown zone with an average payout of $12,173 and an average recorded water depth of 1 inch.
Properties situated within FEMA Zone A should pay the most attention to these flood risks, as this zone accounts for the vast majority of historical insurance claims and recorded water depths in the county.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
In flood insurance claims here that reported a flood depth, the average was 2 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 1990, with 2 claims and $20,000 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.
2 NOAA storm reports from Washington County describe what happened, in the words of the forecasters who covered it. Read the Illinois flood stories →
9 federal disaster declarations since 2002, 1 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Storms, Tornadoes, Straight-line Winds, And Floodng | Jul 13, 2024 |
| Severe Storms And Flooding | Jun 29, 2023 |
| Severe Storms, Straight-line Winds, And Tornadoes | Nov 17, 2013 |
| Severe Storms And Flooding | Apr 19, 2011 |
| Severe Winter Storm And Snowstorm | Jan 31, 2011 |
| Hurricane Katrina Evacuation | Aug 29, 2005 |
| Severe Storms, Tornadoes And Flooding | Apr 21, 2002 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
18 since 1996: 14 flash floods and 4 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flood | Apr 29, 2025 | — |
| Flash Flood | Apr 4, 2025 | — |
| Flash Flood | Jul 26, 2022 | $50,000 |
| Flash Flood | Jul 16, 2021 | — |
| Flash Flood | Apr 3, 2014 | — |
| Flash Flood | Jun 21, 2011 | — |
| Flash Flood | May 8, 2009 | — |
| Flash Flood | Jun 8, 2009 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flood · Apr 29, 2025. During the afternoon of April 29th, a QLCS from Oklahoma and southern Kansas entered southwest Illinois. Although the QLCS had been decaying up to this point, it was still capable of producing severe weather. Wind damage, flooding, and hail were all reported as the complex passed from Randolph County through Marion County.
Flash Flood · Apr 4, 2025. A stationary front over southern Missouri along with ample mid-level forcing, moisture, and efficient rain processes resulted in flash flooding across portions of southwest and south central Illinois.
Flash Flood · Jul 26, 2022. During the early morning of Tuesday, July 26th, 2022, a complex of training thunderstorms set up roughly along the I-70 corridor in Missouri and I-64 corridor in Illinois. Several rounds of thunderstorms with rainfall rates exceeding 2in/hr affected this area, including the St. Louis metropolitan area, through the early hours of July 26th and into the morning commute. Upwards of 11 of rain fell over the course of…
Flash Flood · Jul 16, 2021. Training storms moved through portions of southeast Missouri and southwestern Illinois with up to 4 inches of rain in a short amount of time. There were several reports of flash flooding.
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.