Enter any address in Walworth County, South Dakota to see its FEMA flood zone
River overflow and snowmelt-driven flooding are the primary flood concerns in Walworth County. Over the past 30 years, NOAA Storm Events data shows 10 flood events and 8 flash flood events. Recent flooding in April 2019, for example, was attributed to a combination of heavy snowmelt and a significant mid-April blizzard, leading to widespread inundation of roads and thousands of acres of cropland. Earlier that year, in March 2019, a similar scenario unfolded with snowmelt, ice jams, and heavy rains causing rivers and creeks to flood, damaging infrastructure and threatening some structures.
These events highlight the potential for significant agricultural and infrastructure impacts. Homeowners and businesses located in flood-prone areas, particularly those near rivers and creeks, should be aware of their flood risk. Residents in areas that have experienced flooding in the past, or those without a designated Base Flood Elevation (BFE), should pay particular attention to flood preparedness and potential insurance needs.
Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.
6 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
Walworth County, South Dakota has recorded 18 flood-related events since 1996 according to NOAA's Storm Events Database, including 8 flash floods and 10 river or area floods. The county has received 12 federal disaster declarations, 6 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 And Flooding | Flood | May 21, 2019 |
| Severe Winter Storm, Snowstorm, And Flooding | Flood | Mar 13, 2019 |
| Severe Winter Storm | Severe Storm | Jan 20, 2010 |
| Hurricane Katrina Evacuation | Coastal Storm | Sep 6, 2005 |
| Severe Flooding, Sever Winter Storms,heavy Rains High Winds | Flood | Feb 3, 1997 |
| Severe Winter Storms And Blizzard Conditions | Severe Storm | Jan 3, 1997 |
| Flooding | Flood | Mar 1, 1995 |
| Severe Winter Storms | Snowstorm | Jan 13, 1995 |
NOAA Storm Events Database (1996–2025)
Source: NOAA National Weather Service Storm Events Database.
| Type | Date | Damage |
|---|---|---|
| Flood | Mar 25, 2019 | 0.00K |
| Flood | May 1, 2019 | 0.00K |
| Flood | Jun 1, 2019 | 0.00K |
| Flood | Apr 1, 2019 | 292.30K |
| Flash Flood | May 18, 2018 | 0.00K |
| Flood | May 17, 2018 | 0.00K |
| Flash Flood | May 17, 2018 | 3.00M |
| Flash Flood | Jun 18, 2014 | 0.00K |
| Flood | Jun 20, 2011 | 0.00K |
| Flash Flood | Jun 14, 2011 | 0.00K |
Flood — Mar 25, 2019
Much above normal winter snowfall and melt water/ice jams along with heavy rains in the middle of March brought flooding across parts of central and northeast South Dakota for late March. Rivers and creeks flooded across much of the area along with many fields and roads. The flooding damaged many of the roads and culverts across the region. Some structures were also flooded. Lake levels also ro...
Flood — May 1, 2019
March and April snowmelt and heavy rain flooding along with above normal May precipitation resulted in hundreds of thousands of acres of crops damaged or delayed/unplanted across central and northeast South Dakota. The widespread flooding continued into June with millions of dollars of loss.
Flood — Jun 1, 2019
Spring snowmelt and heavy rain flooding from March, April, and May continued into June. This combined with above normal June rainfall resulted in hundreds of thousands of acres of crops damaged or unplanted across central and northeast South Dakota. For the entire state of South Dakota, nearly 4 million acres of crops were left unplanted as a result of the flooding. Total damaged or unplanted c...
Flood — Apr 1, 2019
The continuation of snowmelt from a much above normal snowfall winter combined with a historic heavy snow/blizzard in mid-April resulted in widespread flooding across central and northeast South Dakota. Countless roads along with thousands of acres of cropland were flooded throughout April. Impacts include damaged roads, culverts, and bridges, and livestock, homes, and businesses were affected....
Flash Flood — May 18, 2018
Extreme rainfall and severe weather occurred along a stationary frontal boundary extending across the region. Thunderstorms training over the same area brought rainfall amounts from 3 to over 13 inches causing extensive flash flooding. Many roads and cropland were flooded and damaged. Several roads had to be barricaded. There was some sandbagging at some farmsteads with several homes receiving ...
Source: NOAA National Weather Service Storm Events Database.
FEMA assigns flood zone designations to areas in Walworth 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 Walworth 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.