42 flood insurance claims·$608,922 paid·6 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 Dallas County, Iowa. 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.
River flooding dominates Dallas County, Iowa, accounting for 121 flood events compared to 53 flash flood events over the last 30 years.
Historical events illustrate these risks across the region. In March 2019, widespread flooding occurred due to a deep snowpack of one to two feet across the region and upstream basins, combined with frozen soils. Later, an April 2022 flash flood brought over 3 inches of rain from a warm front, causing brief town road closures. Another flood event occurred in June 2022 when a deep warm cloud layer and high precipitable water values produced efficient rainfall following storms along a surface boundary.
National Flood Insurance Program claims data shows impacts across different zones. Zone X recorded 21 claims with an average payout of $22,259 and an average water depth of 16 inches. Zone A recorded 16 claims with an average payout of $10,487 and an average water depth of 17 inches. Zone X_UNSHADED recorded 4 claims with an average payout of $28,194 and an average water depth of 12 inches, and Zone UNKNOWN recorded 1 claim with an average payout of $5,048 and an average recorded water depth of 0 inches. Property owners in Zone A and Zone X should pay the closest attention to these flood risks.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
20% of Dallas County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
20 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 17 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 2008, with 9 claims and $96,518 paid, the year of 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.
146 NOAA storm reports from Dallas County describe what happened, in the words of the forecasters who covered it. Read the Iowa flood stories →
20 federal disaster declarations since 1965, 6 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Storms, Tornadoes, And Flooding | May 20, 2024 |
| Severe Storms | Aug 10, 2020 |
| Severe Storms And Flooding | Mar 12, 2019 |
| Severe Storms, Tornadoes, Straight-line Winds, And Flooding | Jun 6, 2018 |
| Severe Storms, Tornadoes, Straight-line Winds, And Flooding | Jun 20, 2015 |
| Severe Storms, Flooding, And Tornadoes | Jun 1, 2010 |
| Severe Winter Storm | Jan 19, 2010 |
| Severe Storms, Tornadoes, And Flooding | May 25, 2008 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
174 since 1996: 53 flash floods and 121 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | Apr 22, 2022 | — |
| Flood | Jun 5, 2022 | — |
| Flood | May 28, 2019 | $100,000 |
| Flood | May 25, 2019 | $100,000 |
| Flood | Mar 16, 2019 | — |
| Flood | Mar 15, 2019 | — |
| Flood | Mar 14, 2019 | $10,000 |
| Flood | Mar 13, 2019 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flash Flood · Apr 22, 2022. A warm front moved across the area late on the evening of April 21 into April 22. While thunderstorms remained below severe criteria, deep saturation and precipitable water values over 1.5 inches allowed for a band of heavier precipitation to set up over a narrow corridor in central Iowa. Several locations received over 3 inches of rain and a few areas saw flash flooding within towns, resulting in brief road closu…
Flood · Jun 5, 2022. A shortwave trough dropped out of the Canadian Rockies and across the upper midwest. Storms developed along a surface boundary in the afternoon, resulting in a few hail reports and a strong wind gust. In addition to the moderate CAPE , the backed wind profile supported some rotation within storms. While no tornadoes occurred there was a funnel cloud reported north of the Des Moines metro. Later that night the dee…
Flood · May 28, 2019. Heavy rain led to additional river flooding toward the end of May 2019. Some of the flooding on the Des Moines River at Eddyville was due to planned dam releases from Lake Red Rock combined with heavy rainfall.
Flood · May 25, 2019. Continued heavy rain and high streamflows led to many rivers going back into flood in late May across central Iowa. Several crests occurred on the Des Moines River at Ottumwa. Many of these were due to planned releases from Lake Red Rock, with some of the water from heavy rainfall.
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 Dallas 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.