Enter any address in Corson County, South Dakota to see its FEMA flood zone
River overflow along the Grand River is the dominant flood character in Corson County. Between May 15th and 16th, 2025, heavy rainfall totaling between 4 to 6 inches caused minor flooding of the Grand River, with the gauge near Little Eagle exceeding flood stage by 0.43 feet. Pastureland experienced minor flooding as a result. More recently, in June 2023, Corson County experienced widespread heavy rainfall leading to minor flooding of Oak Creek near Wakpala.
Over the last 30 years, the NOAA Storm Events Database has recorded 41 flood events and 14 flash flood events in Corson County. One National Flood Insurance Program (NFIP) claim was filed from an unknown flood zone, with an average payout of $450 and an average water depth of -4.0 feet. Residents living in proximity to the Grand River and Oak Creek, as well as those in areas with unknown flood zone designations, should pay particular attention to flood risks.
Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.
16 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
Corson County, South Dakota has recorded 55 flood-related events since 1996 according to NOAA's Storm Events Database, including 14 flash floods and 41 river or area floods. The county has received 27 federal disaster declarations, 3 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.
FEMA Disaster Declarations (1976–2020)
Source: OpenFEMA Disaster Declarations Summaries.
| Declaration | Type | Date |
|---|---|---|
| Covid-19 | Biological | Jan 20, 2020 |
| Covid-19 Pandemic | Biological | Jan 20, 2020 |
| Severe Storms, Tornadoes, And Flooding | Flood | Jun 13, 2014 |
| Severe Winter Storm, Snowstorm, And Flooding | Severe Storm | Oct 3, 2013 |
| Severe Storms, Tornado, And Flooding | Severe Storm | May 24, 2013 |
| Severe Winter Storm | Severe Storm | Apr 2, 2010 |
| Severe Winter Storm | Severe Storm | Jan 20, 2010 |
| Severe Storms And Flooding | Severe Storm | Mar 11, 2009 |
| Severe Winter Storm And Record And Near Record Snow | Snowstorm | Nov 5, 2008 |
| 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 | May 20, 2025 | 0.00K |
| Flood | May 16, 2025 | 0.00K |
| Flood | Jun 25, 2023 | 0.00K |
| Flood | Apr 11, 2023 | 0.00K |
| Flood | May 12, 2022 | 0.00K |
| Flood | Jun 10, 2021 | 0.00K |
| Flash Flood | Jun 8, 2021 | 0.00K |
| Flood | Mar 7, 2020 | 0.00K |
| Flood | Mar 27, 2019 | 0.00K |
| Flood | Mar 23, 2019 | 0.00K |
Flood — May 20, 2025
More seasonal rainfall was observed in middle to late May across north central South Dakota. A local area of moderate to heavy rain, between 4 to 6 inches, was observed with a system on May 15th and 16th, with the COOP observer located 8 miles south southwest of Keldron recording 5.6 inches of moisture. This would result in minor flooding of the Grand River, with the gauge near Little Eagle top...
Flood — May 16, 2025
More seasonal rainfall was observed in middle to late May across north central South Dakota. A local area of moderate to heavy rain, between 4 to 6 inches, was observed with a system on May 15th and 16th, with the COOP observer located 8 miles south southwest of Keldron recording 5.6 inches of moisture. This would result in minor flooding of the Grand River, with the gauge near Little Eagle top...
Flood — Jun 25, 2023
Several rounds of showers and thunderstorms across eastern Corson County from the afternoon of June 20th through the morning of the 23rd culminated with a widespread heavy rainfall event from the evening of the 23rd through the evening of the 24th. Some 5-day rainfall totals include 4.92 2 miles southwest of McLaughlin, 4.51 2 miles north-northwest of Mobridge, 3.85 at the Mobridge Municipal Ai...
Flood — Apr 11, 2023
Snowmelt resulted in flooding along Oak Creek. Temperatures on April 11th hit a record 90 degrees in Mobridge after several days of mild weather and rapid snowmelt. The river gauge near Wakpala peaked at 15.92 feet early April 12th, just below major flood stage, though this mainly affected agricultural lands.
Flood — May 12, 2022
Multiple days of light to moderate rain on top of saturated soils resulted in brief minor flooding for multiple rivers in the forecast area. Rainfall amounts for the 5 day period leading up to the flooding totaled just less than 3 inches near these river basins. Flooding developed on May 12th in the afternoon, with Mud Creek near Rauville peaking just at the flood stage of 9.0 feet before falli...
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 Corson 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 Corson 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.