1,550 flood insurance claims·$38.3M paid·8 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 Polk 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.
Polk County experiences a flood risk profile dominated by regular river floods alongside frequent flash flooding driven by summer thunderstorms. Historical records from the last 30 years document 177 flood events and 118 flash flood events, which resulted in three deaths. Recent activity includes diurnally driven storms in July 2025 and multi-round heavy rainfall events producing severe weather and localized flooding in May 2024.
National Flood Insurance Program records indicate that property damage is heavily concentrated in high-risk zones, with Zone A recording 1,137 claims at an average payout of $24,308 and an average recorded water depth of 6 inches. Moderate- and lower-risk areas also experience significant impacts; Zone X accounts for 308 claims with a higher average payout of $60,931 and an average recorded water depth of 10 inches. Additional claims are distributed across Zone X_UNSHADED (34 claims, average payout $42,631, average water depth 2 inches), Zone X_SHADED (30 claims, average payout $11,994, average water depth 2 inches), and Zone UNKNOWN (41 claims, average payout $6,829, average water depth 6 inches).
Homeowners, real estate agents, and journalists should pay the closest attention to properties located within Zone A due to the high volume of historical claims, as well as properties in Zone X where average claim payouts are substantially higher.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
5% of Polk County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
1,201 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 7 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 1993, with 454 claims and $8.5M paid, the year of Severe Storms & 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.
251 NOAA storm reports from Polk County describe what happened, in the words of the forecasters who covered it. Read the Iowa flood stories →
20 federal disaster declarations since 1965, 8 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Storms, Tornadoes, And Flooding | May 20, 2024 |
| Severe Storms And Tornadoes | Apr 26, 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, Flooding, And Tornadoes | Jun 1, 2010 |
| Severe Storms, Tornadoes, And Flooding | May 25, 2008 |
| Severe Winter Storms | Feb 23, 2007 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
295 since 1996: 118 flash floods and 177 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | Jul 20, 2025 | $20,000 |
| Flood | May 24, 2024 | — |
| Flood | May 22, 2024 | — |
| Flash Flood | Apr 22, 2022 | — |
| Flash Flood | Aug 19, 2022 | $10,000 |
| Flood | Jun 7, 2022 | — |
| Flash Flood | Jun 22, 2020 | — |
| Flood | May 24, 2019 | $100,000 |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flash Flood · Jul 20, 2025. Diurnally driven afternoon storms on Sunday, July 20th, 2025, developed within an unstable environment with CAPE values over 3000 J/kg and 40 to 45 kts of effective shear. Despite this unstable and decently sheared environment, several factors limited the severe weather potential, including weak low-level flow, a warm layer aloft, and an overall lack of forcing. This led to disorganized storms that remained below…
Flood · May 24, 2024. There were several rounds of rainfall over the period starting around May 20 through around May 25. This is when there were two rounds of heavy rainfall along with severe thunderstorms including tornadoes and straight-line winds, detailed in respective severe entries for the month. 60-hour rainfall totals ending May 21 at 7pm were up to 4 to 6 inches over portions of Marshall, Tama, Poweshiek, and Jasper Counties.…
Flood · May 22, 2024. There were several rounds of rainfall over the period starting around May 20 through around May 25. This is when there were two rounds of heavy rainfall along with severe thunderstorms including tornadoes and straight-line winds, detailed in respective severe entries for the month. 60-hour rainfall totals ending May 21 at 7pm were up to 4 to 6 inches over portions of Marshall, Tama, Poweshiek, and Jasper Counties.…
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…
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 Polk 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.