Enter any address in Brown County, South Dakota to see its FEMA flood zone
Flooding, including flash flooding, has been a recurring event in Brown County, SD over the last 30 years. In July 2025, thunderstorms brought heavy rainfall and high winds to Aberdeen, leading to flash flooding. Later that summer, in August and September 2025, the James River near Stratford experienced flooding conditions that persisted for weeks, primarily impacting agricultural areas.
Homeowners in Zone A, which has seen the highest number of National Flood Insurance Program claims with an average payout of $9,549 and water depths averaging 2.8 feet, should be particularly aware of their flood risk. Properties located near rivers, such as the James River, or in areas prone to flash flooding from heavy rainfall events, should also pay close attention to flood advisories and potential risks.
Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.
50 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
Brown County, South Dakota has recorded 192 flood-related events since 1996 according to NOAA's Storm Events Database, including 22 flash floods and 170 river or area floods. The county has received 19 federal disaster declarations, 10 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.
FEMA Disaster Declarations (1969–2023)
Source: OpenFEMA Disaster Declarations Summaries.
| Declaration | Type | Date |
|---|---|---|
| Flooding | Flood | Apr 9, 2023 |
| Covid-19 | Biological | Jan 20, 2020 |
| Covid-19 Pandemic | Biological | Jan 20, 2020 |
| Severe Winter Storm, Snowstorm, And Flooding | Flood | Mar 13, 2019 |
| Flooding | Flood | Mar 11, 2011 |
| Flooding | Flood | Mar 10, 2010 |
| Severe Storms And Flooding | Severe Storm | Mar 11, 2009 |
| Severe Storms, Tornadoes, And Flooding | Severe Storm | May 4, 2007 |
| Severe Winter Storm | Severe Storm | Nov 27, 2005 |
| Hurricane Katrina Evacuation | Coastal Storm | Sep 6, 2005 |
NOAA Storm Events Database (1996–2025)
Source: NOAA National Weather Service Storm Events Database.
| Type | Date | Damage |
|---|---|---|
| Flood | Aug 26, 2025 | 0.00K |
| Flood | Aug 17, 2025 | 0.00K |
| Flood | Jul 15, 2025 | 0.00K |
| Flood | Aug 10, 2025 | 0.00K |
| Flash Flood | Jul 4, 2025 | 0.00K |
| Flood | Sep 1, 2025 | 0.00K |
| Flood | Oct 1, 2025 | 0.00K |
| Flood | Apr 18, 2023 | 0.00K |
| Flood | Apr 17, 2023 | 0.00K |
| Flood | Apr 16, 2023 | 0.00K |
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 b...
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.
Flash Flood — Jul 4, 2025
Thunderstorms on the Fourth of July produced a strong wind gust with the Aberdeen Regional Airport Automated Surface Observing System reaching a peak of 81 mph. Heavy rainfall from these storms also led to flash flooding in Aberdeen and later in Watertown.
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 Brown County, South Dakota:
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 Brown County, South Dakota 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.