291 flood insurance claims·$7.7M 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 Lake 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.
Overland and river flooding driven by heavy multi-day rainfall and saturated or frozen ground dominates the flood risk in Lake County, South Dakota.
Recent events illustrate these hazards. In March 2019, rainfall of one to three inches falling on frozen ground and an existing snowpack caused considerable overland flooding and water rescues. Later, a multi-day heavy rainfall event from June 20 to 22, 2024, produced widespread rainfall totals between 5 and 15 inches, leading to major to record river flooding and extensive overland impacts. NOAA storm records for the past 30 years document 14 general flood events and 12 flash flood events, resulting in one fatality.
Property owners in FEMA-designated Zone A should pay the most attention to flood risk, as this zone accounts for the highest volume of National Flood Insurance Program claims at 169 claims, with an average payout of $23,674 and an average recorded water depth of 7 inches. However, properties in Zone X also face meaningful risk, registering 95 claims with a higher average payout of $44,642 and an average recorded water depth of 1 inch.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
10% of Lake County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
187 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 4 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 2019, with 146 claims and $6.4M paid, the year of Severe Winter Storm, Snowstorm, and Flooding and 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.
11 NOAA storm reports from Lake County describe what happened, in the words of the forecasters who covered it. Read the South Dakota flood stories →
20 federal disaster declarations since 1969, 9 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Storms, Straight-line Winds, And Flooding | Jun 16, 2024 |
| Severe Storm, Straight-line Winds, Tornadoes, And Flooding | May 12, 2022 |
| Severe Storms, Tornadoes, And Flooding | Sep 9, 2019 |
| Severe Winter Storm, Snowstorm, And Flooding | Mar 13, 2019 |
| Flooding | Mar 11, 2011 |
| Severe Storms And Flooding | Sep 22, 2010 |
| Flooding | Mar 10, 2010 |
| Severe Storms, Tornadoes, And Flooding | May 4, 2007 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
26 since 1996: 12 flash floods and 14 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | Jun 21, 2024 | — |
| Flood | Jun 20, 2024 | $750,000 |
| Flood | Mar 18, 2019 | — |
| Flood | Mar 14, 2019 | $310,000 |
| Flood | Sep 12, 2019 | $5,000 |
| Flood | Sep 12, 2019 | $1.4M |
| Flash Flood | Sep 12, 2019 | $100,000 |
| Flash Flood | Sep 11, 2019 | $25,000 |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flash Flood · Jun 21, 2024. Southeast South Dakota was on the initial development end of a second mesoscale convective system in just two days as a frontal boundary remained anchored just south of the area. Scattered storms produced some spotty wind gusts as well as locally flooding rainfall.
Flood · Jun 20, 2024. A multi-day significant heavy rainfall event from June 20-22 resulted in widespread rain totals between 5 and 10 inches with pockets in excess of 15 inches across portions of southeast South Dakota, northwest Iowa, and southwest Minnesota. As rainfall reached area streams and rivers, major to record flooding was observed, devastating several towns and communities. Extensive overland flooding also resulted in signi…
Flood · Mar 18, 2019. A historic flooding event unfolded as heavy rainfall drenched the area on March 13-14, 2019. With frozen and impervious ground, full and rapid runoff was maximized. In addition to the rainfall, between 1 and 3 inches of snow water equivalent remained in the snow pack south of Interstate 90, with 3 to 6 inches of snow water equivalent north of Interstate 90. Fifteen river gage sites measured record stages around t…
Flood · Mar 14, 2019. Rainfall of one to three inches on frozen ground and into a snow pack with between 2 and 5 inches of liquid water equivalent resulted in considerable overland flooding.||One of the hardest hit areas was around Yankton, where a No Travel Advisory was issued for the city on March 13-14. Businesses along north Highway 81 toward Yankton Mall had considerable ponding of water. Water rescues were necessary as cars sta…
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 Lake 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.