85 flood insurance claims·$608,528 paid·4 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 Grant 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 standard riverine flooding evenly dominate Grant County, with equal numbers of flood and flash flood events recorded over the last 30 years. Recent impacts are exemplified by storms in August 2025, which caused widespread flooding in northern areas, including residential inundation in the town of Bagley due to a debris blockage, and heavy rainfall leading to flash flooding in Lancaster.
National Flood Insurance Program claims data indicates that flood risks extend beyond high-risk zones. Zone A accounts for 42 claims with an average payout of $10,225 and an average recorded water depth of 2 inches. Meanwhile, Zone X properties also face significant risk, recording 20 claims with an average payout of $11,211 and an average recorded water depth of 4 inches, alongside 15 claims in unshaded Zone X averaging $10,708 and 2 inches of water depth.
Homeowners, real estate agents, and journalists should pay the closest attention to properties located within both designated high-risk Special Flood Hazard Areas (Zone A) and moderate-to-low risk areas (Zone X and unshaded Zone X), where historical claims demonstrate that property inundation and financial losses routinely occur.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
28% of Grant County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
58 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 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 2001, with 13 claims and $98,975 paid, the year of Flooding, Severe Storms and Tornadoes.
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.
77 NOAA storm reports from Grant County describe what happened, in the words of the forecasters who covered it. Read the Wisconsin flood stories →
20 federal disaster declarations since 1965, 4 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Storms, Straight-line Winds, Flooding, Landslides, And Mud | Jul 19, 2017 |
| Severe Storms, Flooding, And Mudslides | Jun 20, 2013 |
| Severe Winter Storm And Snowstorm | Jan 31, 2011 |
| Severe Storms, Tornadoes, And Flooding | Jul 20, 2010 |
| Severe Storms, Tornadoes, And Flooding | Jun 5, 2008 |
| Severe Storms And Flooding | Aug 18, 2007 |
| Hurricane Katrina Evacuation | Aug 29, 2005 |
| Severe Storms And Flooding | May 7, 2004 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
138 since 1996: 69 flash floods and 69 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flood | Aug 18, 2025 | — |
| Flash Flood | Aug 17, 2025 | $75,000 |
| Flash Flood | Jul 11, 2025 | — |
| Flash Flood | Jul 11, 2025 | $25,000 |
| Flash Flood | Jul 11, 2025 | $10,000 |
| Flash Flood | Jul 11, 2025 | $5,000 |
| Flash Flood | Aug 10, 2025 | $5,000 |
| Flash Flood | Aug 10, 2025 | $300,000 |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flood · Aug 18, 2025. Heavy rainfall during the middle of August resulted in minor flooding along portions of the Trempealeau and Platte rivers in Western Wisconsin.
Flash Flood · Aug 17, 2025. Rounds of strong to severe storms throughout the day on August 16th resulted in instances of large hail, damaging winds and flash flooding in western Wisconsin. Hail with these storms reached up to golf ball sized near New Lisbon along with instances of tree damage. Later into the evening, additional storms moved through Grant County and produced heavy rainfall leading to flash flooding in Lancaster along with som…
Flash Flood · Jul 11, 2025. During the afternoon hours on July 11th, severe storms moved through Grant County bringing a few instances of severe wind gusts between 60 and 70 mph resulting in sporadic wind damage. These storms produced heavy rainfall as well which resulted in flash flooding of some county roads and some flooding of residences in Lancaster.
Flash Flood · Aug 10, 2025. Two separate rounds of storms moved through Grant County on August 10th bringing both heavy rain and flash flooding along with them. The first round of storms moved through during the early morning hours bringing widespread flooding issues to northern portions of the county. The worst of the flash flooding was in the town of Bagley where a debris blockage resulted in storm water inundating residences in the town.…
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 Grant 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.