484 flood insurance claims·$3.3M paid·10 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 Brown County, South Dakota. 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.
Prolonged riverine flooding and heavy rainfall events dominate the flood profile, supported by 170 general flood events and 22 flash flood events recorded over the last 30 years in Brown County.
Recent occurrences illustrate these risks. In July 2025, thunderstorms produced heavy rainfall that led to flash flooding in Aberdeen. Later that summer, above-normal rainfall and upstream releases caused the James River near Stratford to go into flood on August 26, 2025, and remain in flood through the end of the month. A separate flooding event persisted into late September 2025, when the James River near Stratford crested at 1.39 feet above flood stage and impacted agricultural bottomlands.
Properties situated within designated flood zones should pay the most attention to these risks. National Flood Insurance Program records show significant claim activity across multiple zones, including 171 claims in Zone A with an average payout of $13,846 and an average recorded water depth of 10 inches. Additionally, moderate risk areas recorded numerous claims, such as 120 claims in Zone X with an average payout of $10,296 and an average recorded water depth of 11 inches, and 96 claims in unshaded Zone X with an average payout of $2,909 and an average recorded water depth of 8 inches.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
36% of Brown County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
269 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 8 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 2007, with 169 claims and $1.9M 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.
50 NOAA storm reports from Brown County describe what happened, in the words of the forecasters who covered it. Read the South Dakota flood stories →
19 federal disaster declarations since 1969, 10 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Flooding | Apr 9, 2023 |
| Severe Winter Storm, Snowstorm, And Flooding | Mar 13, 2019 |
| Flooding | Mar 11, 2011 |
| Flooding | Mar 10, 2010 |
| Severe Storms And Flooding | Mar 11, 2009 |
| Severe Storms, Tornadoes, And Flooding | May 4, 2007 |
| Severe Winter Storm | Nov 27, 2005 |
| Hurricane Katrina Evacuation | Sep 6, 2005 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
192 since 1996: 22 flash floods and 170 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flood | Aug 26, 2025 | — |
| Flood | Aug 17, 2025 | — |
| Flood | Jul 15, 2025 | — |
| Flood | Aug 10, 2025 | — |
| Flash Flood | Jul 4, 2025 | — |
| Flood | Sep 1, 2025 | — |
| Flood | Oct 1, 2025 | — |
| Flood | Apr 18, 2023 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flood · Aug 26, 2025. Above normal rainfall and releases from North Dakota would result in the James River near Stratford going into flood on the morning of August 26th. The river would remain in flood through the end of the month.
Flood · Aug 17, 2025. Brief but intense heavy rainfall from thunderstorms, on top of weeks of wet weather, resulted in additional flooding across Marshall, Hamlin, Codington, and Deuel counties starting on the 17th and persisting well into the 18th. An estimated 3 inches of rain fell in Lake Poinsett, while 1.63 inches was recorded by the COOP sensor 20 miles north northeast of Aberdeen, 1.62 inches was submitted by the CoCoRaHS volun…
Flood · Jul 15, 2025. Thunderstorms during the afternoon produced flooding in Aberdeen. A separate storm that formed along the Missouri River north of Oacoma was responsible for a waterspout.
Flood · Aug 10, 2025. Cumulative heavy rainfall from May through mid-August, along with reservoir releases in North Dakota, resulted in flooding along the James River. Impacts from the flooding were limited to agricultural lands.
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 Brown 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.