13 flood insurance claims·$155,059 paid·9 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 Marshall 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.
Traditional riverine floods and sudden flash floods from summer thunderstorms dominate the flood risk profile in Marshall County, South Dakota, with the NOAA Storm Events Database recording 22 floods and 12 flash floods over the last 30 years. Recent events illustrate this pattern, such as the August 15, 2025 flash flood when over 4.5 inches of rain fell in a 48-hour period in Britton, overwhelming drainage systems and causing local flooding. This followed an event on August 17, 2025, when brief, intense rainfall from thunderstorms on top of weeks of wet weather resulted in additional flooding across Marshall County.
National Flood Insurance Program records indicate that flood risks extend beyond designated high-risk flood areas. Zone X properties account for 8 claims with an average payout of $17,164 and an average recorded water depth of 1 inch. Unshaded Zone X properties represent 4 claims with an average payout of $6,010 and an average recorded water depth of 2 inches, while Zone A properties recorded 1 claim with an average payout of $10,867 and an average recorded water depth of 0 inches.
Homeowners, real estate agents, and journalists should pay the most attention to properties located in lower-lying areas and zones susceptible to localized drainage overloads, including those situated in both unshaded and standard Zone X areas where historical claims indicate recurring water accumulation.
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 2011, with 8 claims and $134,637 paid, the year of 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.
12 NOAA storm reports from Marshall County describe what happened, in the words of the forecasters who covered it. Read the South Dakota flood stories →
20 federal disaster declarations since 1976, 9 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Flooding | Apr 9, 2023 |
| Severe Winter Storm, Snowstorm, And Flooding | Mar 13, 2019 |
| Severe Winter Storm | Dec 24, 2016 |
| 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 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
34 since 1996: 12 flash floods and 22 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flood | Aug 17, 2025 | — |
| Flash Flood | Aug 15, 2025 | — |
| Flash Flood | Jun 13, 2025 | — |
| Flash Flood | Aug 5, 2025 | — |
| Flood | Apr 12, 2023 | $150,000 |
| Flood | Jul 25, 2020 | — |
| Flood | Mar 27, 2019 | — |
| Flood | May 1, 2019 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
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…
Flash Flood · Aug 15, 2025. Strong storms during the early morning hours of August 15th would generate winds in excess of 70 mph at Sunset Colony, and half-dollar to ping pong sized hail observed by the Marshall County Emergency Manager in Britton. Total rainfall in Britton over a 48 hour period exceeded 4.5 inches, with this latest round of storms overwhelming drainage systems and causing flooding in town.
Flash Flood · Jun 13, 2025. A broad low-pressure system brought several rounds of rain and a few strong, isolated thunderstorms to northeast South Dakota. The rain began on the morning of June 12th. A break in the rain mid-day allowed the atmosphere to destabilize, which led to stronger storms in the afternoon. One storm produced penny-sized hail 3 miles west of Blunt. Another storm in Mansfield produced penny to nickel-sized hail and winds…
Flash Flood · Aug 5, 2025. A line of storms produced large hail and high winds during the afternoon and evening of August 5th, and into the early morning hours of August 6th. The largest sized hail measured at 3 inches in diameter was observed in Hoven. Later in the evening, a peak wind gust of 99 mph was recorded on a weather station out at Sandy Shore State Park, while the Watertown Regional Airport ASOS would record a peak gust of 68 mph…
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 Marshall 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.