FloodZoneMap.org

Cass County, Iowa Flood Zones

Check an Address in Cass County

Enter any address in Cass County, Iowa to see its FEMA flood zone

The Flooding Character of Cass County

Flash flooding events have been more frequent than general flooding in Cass County, IA over the last 30 years, with 34 flash flood events recorded compared to 17 flood events. Recent flooding has been influenced by factors such as heavy rain on snowmelt, as seen in March 2019, and intense rainfall events, such as those occurring in May 2019.

National Flood Insurance Program (NFIP) data indicates that properties in Zone A have experienced the most claims, with an average payout of $7,375 and an average water depth of 0.8 feet. While Zone X and Zone X_UNSHADED have seen fewer claims, they have recorded deeper water depths in some instances. Residents in areas designated as Zone A, as well as those in Zone X_UNSHADED, should pay particular attention to flood risk.

Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.

Read First-Hand Flood Stories from Cass County

45 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.

Read Iowa flood stories →

Flood Risk Data for Cass County

Cass County, Iowa has recorded 51 flood-related events since 1996 according to NOAA's Storm Events Database, including 34 flash floods and 17 river or area floods. The county has received 19 federal disaster declarations, 7 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.

Cass County Disaster History

FEMA Disaster Declarations (1965–2021)

Disaster Declarations
19
Flood/Coastal Disasters
7
Latest Disaster
Severe Storms, Straight-line Winds, And Tornadoes (2021-12-15)

Source: OpenFEMA Disaster Declarations Summaries.

Recent Disaster Declarations in Cass County

DeclarationTypeDate
Severe Storms, Straight-line Winds, And TornadoesSevere StormDec 15, 2021
Covid-19BiologicalJan 20, 2020
Covid-19 PandemicBiologicalJan 20, 2020
Severe Storms And FloodingFloodMar 12, 2019
Severe Winter StormSevere StormJan 19, 2010
Severe Winter Storms And SnowstormSevere StormDec 23, 2009
Severe Storms, Tornadoes, And FloodingSevere StormMay 25, 2008
Severe Storms, Flooding, And TornadoesSevere StormMay 5, 2007
SnowSnowstormFeb 28, 2007
Hurricane Katrina EvacuationHurricaneAug 29, 2005

Recorded Flood Events in Cass County

NOAA Storm Events Database (1996–2025)

Total Flood Events
51
River/Area Floods
17
Flash Floods
34
Total Property Damage
$30.4M

Source: NOAA National Weather Service Storm Events Database.

Recent Flood Events in Cass County

TypeDateDamage
Flash FloodSep 24, 20195.00K
Flash FloodMay 24, 201950.00K
Flash FloodMay 24, 201920.00K
FloodMar 14, 20190.00K
FloodMar 13, 201910.00K
Flash FloodMay 26, 201625.00K
Flash FloodMay 11, 2014100.00K
Flash FloodSep 9, 201415.00K
Flash FloodJun 3, 201450.00K
Flash FloodApr 14, 201210.00K

Cass County Flood History

Flash Flood — Sep 24, 2019

A relatively routine setup for strong to severe storms took place on the 24th of September. A cold front entered the state from the northwest during the late afternoon and early evening hours, entering an environment with strong low level moisture inflow, SBCAPE values in excess of 2000 J/kg, and effective bulk shear around 40 kts. With frontal forcing and the aforementioned conditions, storms ...

Flash Flood — May 24, 2019

The setup over Iowa was primed for a heavy rainfall event for a few reasons, including persistent SW 500 mb flow, a strong and SW oriented 850 mb jet, strong low level moisture transport, and elevated CAPE around 1000-2000 J/kg. Precipitable water values, given the strong moisture transport into the area, rose into the neighborhood of 1.7 inches throughout the event as well. While effective bul...

Flood — Mar 14, 2019

Higher than average snowfall through the winter created a wet snowpack across much of Iowa which was still present into early March. A large storm system impacted the region through the middle of March which brought heavy rain and warm temperatures to the state. This system allowed much of the snowpack to melt across the state within a few days to a week. This heavy rain fell on frozen ground a...

Flood — Mar 13, 2019

Reports from the 13h through the 19th in this entry. ||A relatively deep and widespread snowpack existed across the region during early to mid March. Many areas in central and northern Iowa had around a foot to two feet of snow on the ground, along with many areas in upstream river basins in Minnesota and the Dakotas having similar or deeper snowpacks on the ground. Additionally, with the below...

Flash Flood — May 26, 2016

On the afternoon of the 25th, a cold front progressed into portions of central and eastern Nebraska and eventually stalled out in eastern Nebraska. During the evening hours storms that initiated earlier in the day in western Nebraska continued to make their way across Nebraska and into Iowa and produced a number of high wind, damaging wind, and hail reports. Prior to the main line, a severe s...

Source: NOAA National Weather Service Storm Events Database.

Cass County NFIP Flood Insurance Claims

Total Claims Filed
51
Total Paid Out
$299,713
Avg Claim
$6,970
Avg Water Depth
3.1 ft

Claims by Flood Zone

A Zones (High Risk)
34
X Shaded (500-yr)
1
X Unshaded (Low)
1

Source: OpenFEMA NFIP Individual Claims (2.25M records analyzed).

Flood Zone Types in Cass County

FEMA assigns flood zone designations to areas in Cass County, Iowa:

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.

View all flood zone types →

Flood Insurance in Cass County

Properties in Cass County, Iowa 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.