FloodZoneMap.org

Cass County, Illinois Flood Zones

Check an Address in Cass County

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

The Flooding Character of Cass County

Flash flooding from heavy rainfall events is the dominant flood character in Cass County. Over the last 30 years, NOAA Storm Events data shows 25 flash flood events and 11 flood events. For example, localized flash flooding occurred in May 2023 due to 2 to 3 inches of rainfall, and in July 2022, 2 to 4 inches of rain resulted in flash flooding.

National Flood Insurance Program (NFIP) claims data indicates that properties in Zone A have experienced the highest average water depths and payouts. Claims in Zone UNKNOWN and Zone X also show significant payouts, with average water depths varying. Homeowners in Zone A, as well as those in areas with unknown flood zone designations or general Zone X, 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

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

Read Illinois flood stories →

Flood Risk Data for Cass County

Cass County, Illinois has recorded 36 flood-related events since 1996 according to NOAA's Storm Events Database, including 25 flash floods and 11 river or area floods. The county has received 21 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 (1973–2021)

Disaster Declarations
21
Flood/Coastal Disasters
7
Latest Disaster
Severe Storms, Straight-line Winds, And Tornadoes (2021-12-10)

Source: OpenFEMA Disaster Declarations Summaries.

Recent Disaster Declarations in Cass County

DeclarationTypeDate
Severe Storms, Straight-line Winds, And TornadoesTornadoDec 10, 2021
Covid-19BiologicalJan 20, 2020
Covid-19 PandemicBiologicalJan 20, 2020
Severe Storms And FloodingFloodFeb 24, 2019
Severe Storms, Straight-line Winds, And FloodingFloodApr 16, 2013
Severe Winter Storm And SnowstormSnowstormJan 31, 2011
Severe Storms And FloodingSevere StormSep 13, 2008
Hurricane Katrina EvacuationHurricaneAug 29, 2005
Severe Storms, Tornadoes And FloodingTornadoApr 21, 2002
Winter Storm 1/1/99SnowstormJan 1, 1999

Recorded Flood Events in Cass County

NOAA Storm Events Database (1996–2025)

Total Flood Events
36
River/Area Floods
11
Flash Floods
25
Total Property Damage
$2.2M

Source: NOAA National Weather Service Storm Events Database.

Recent Flood Events in Cass County

TypeDateDamage
Flash FloodMay 14, 20234.00K
Flash FloodMay 14, 20235.00K
Flash FloodJul 8, 20220.00K
FloodOct 24, 20210.00K
FloodApr 29, 20170.00K
Flash FloodApr 29, 20170.00K
Flash FloodJun 26, 20150.00K
Flash FloodMay 27, 20130.00K
FloodApr 18, 20130.00K
FloodMay 1, 20130.00K

Cass County Flood History

Flash Flood — May 14, 2023

A stationary frontal boundary extending from northern Missouri to western Kentucky triggered clusters of strong to severe thunderstorms across parts of central Illinois during the late afternoon and evening of May 14th. Most of the storms were concentrated along a Rushville...to Springfield...to Salem line. Scattered wind damage and hail as large as golf balls occurred across this area. In a...

Flash Flood — Jul 8, 2022

A weak low pressure system was located in central Missouri, with a slow moving warm front draped across southern Illinois. Widespread thunderstorms developed along the warm front during the pre-dawn hours, with the complex tracking southeast during the morning. The heaviest rains occurred near and south of I-72, where 2 to 4 inches of rain fell, resulting in a few instances of flash flooding.

Flood — Oct 24, 2021

Low pressure tracking from near Kansas City around midday on October 24th into central Illinois during the evening of the 24th triggered two distinct bands of pre-frontal convection. Some of the storms produced damaging wind gusts of 60 to 70mph and hail as large as golf balls. In addition, heavy rainfall of 2 to 4 inches occurred...which led to localized flash flooding.

Flood — Apr 29, 2017

Heavy rainfall impacted central and southeast Illinois from April 29th into April 30th...creating flash flooding, which led to widespread areal flooding. Periods of thunderstorms with very high rainfall rates dropped 2.00 to 6.50 inches of rain across much of central and southeast Illinois from April 29th into early on May 1st. This rainfall, occurring on top of already saturated soils, created...

Flash Flood — Apr 29, 2017

Low pressure tracking along a stationary frontal boundary near the I-70 corridor brought widespread strong to severe thunderstorms to much of central and southeast Illinois during the late afternoon and evening of April 29th. A tornado briefly touched down in an open field northeast of Alexander in Morgan County. Elsewhere, thunderstorms packed winds of 60-70mph and caused significant wind da...

Source: NOAA National Weather Service Storm Events Database.

Cass County NFIP Flood Insurance Claims

Total Claims Filed
141
Total Paid Out
$680,901
Avg Claim
$6,134
Avg Water Depth
8.0 ft

Claims by Flood Zone

A Zones (High Risk)
56
X Shaded (500-yr)
2
X Unshaded (Low)
16

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, Illinois:

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, Illinois 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.