Enter any address in Grundy County, Illinois to see its FEMA flood zone
Flash flooding from heavy rainfall is a significant flood character in Grundy County. Between 1993 and 2023, NOAA Storm Events data recorded 25 flood events and 17 flash flood events. For example, on July 13, 2021, a slow-moving thunderstorm caused torrential rain, leading to flash flooding, damaged roads, and at least four damaged bridges in western Grundy County. More recently, on January 15, 2024, ice jams on the Kankakee River resulted in localized flooding.
National Flood Insurance Program (NFIP) data shows a mix of flood zones with varying claim payouts and water depths. Zone A, with 186 claims, averaged $22,227 in payouts and 3.9 feet of water depth. Zone X had 26 claims with an average payout of $23,073 and 2.8 feet of water depth, while Zone X_SHADED had 4 claims with an average payout of $19,495 and 7.5 feet of water depth. Homeowners in Zone A, as well as those in areas prone to river overflow or experiencing significant water depth during flood events, should pay particular attention to flood risk.
Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.
12 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
Grundy County, Illinois has recorded 42 flood-related events since 1996 according to NOAA's Storm Events Database, including 17 flash floods and 25 river or area floods. The county has received 15 federal disaster declarations, 4 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.
FEMA Disaster Declarations (1972–2020)
Source: OpenFEMA Disaster Declarations Summaries.
| Declaration | Type | Date |
|---|---|---|
| Covid-19 | Biological | Jan 20, 2020 |
| Covid-19 Pandemic | Biological | Jan 20, 2020 |
| Severe Storms, Straight-line Winds, And Tornadoes | Tornado | Nov 17, 2013 |
| Severe Storms, Straight-line Winds, And Flooding | Flood | Apr 16, 2013 |
| Severe Winter Storm And Snowstorm | Snowstorm | Jan 31, 2011 |
| Severe Storms And Flooding | Severe Storm | Sep 13, 2008 |
| Severe Storms And Flooding | Severe Storm | Aug 20, 2007 |
| Hurricane Katrina Evacuation | Hurricane | Aug 29, 2005 |
| Illinois Winter Snow Storms | Snowstorm | Dec 11, 2000 |
| Winter Storm 1/1/99 | Snowstorm | Jan 1, 1999 |
NOAA Storm Events Database (1996–2025)
Source: NOAA National Weather Service Storm Events Database.
| Type | Date | Damage |
|---|---|---|
| Flood | Jan 15, 2024 | 0.00K |
| Flood | Jul 13, 2021 | 0.00K |
| Flood | Jul 12, 2021 | 0.00K |
| Flash Flood | Jul 12, 2021 | 300.00K |
| Flood | May 17, 2020 | 0.00K |
| Flood | Sep 28, 2019 | 0.00K |
| Flash Flood | Sep 27, 2019 | 0.00K |
| Flood | May 1, 2019 | 0.00K |
| Flood | Feb 19, 2018 | 0.00K |
| Flash Flood | Aug 28, 2016 | 5.00K |
Flood — Jan 15, 2024
Very cold temperatures led to rapid ice formation on rivers. Localized flooding due to ice jams occurred along portions of the Kankakee River.
Flood — Jul 13, 2021
Scattered thunderstorms moved across portions of central Illinois during the afternoon and evening of July 12th. One storm moved very slowly over eastern La Salle and western Grundy Counties. Torrential rain produced flash flooding in these areas with numerous roads flooded and at least four bridges damaged.
Flood — Jul 12, 2021
Scattered thunderstorms moved across portions of central Illinois during the afternoon and evening of July 12th. One storm moved very slowly over eastern La Salle and western Grundy Counties. Torrential rain produced flash flooding in these areas with numerous roads flooded and at least four bridges damaged.
Flash Flood — Jul 12, 2021
Scattered thunderstorms moved across portions of central Illinois during the afternoon and evening of July 12th. One storm moved very slowly over eastern La Salle and western Grundy Counties. Torrential rain produced flash flooding in these areas with numerous roads flooded and at least four bridges damaged.
Flood — May 17, 2020
After two rounds of heavy rain in the middle of May, major river flooding occurred on the Des Plaines, Illinois and Mazon Rivers. Rainfall totals for May 14th to May 18th included 7.85 inches at Chicago O'Hare Airport (ORD); 6.66 inches at Waukegan Airport (UGN); 6.64 inches at DuPage Airport (DPA); 6.25 inches at Midway Airport (MDW); 5.43 inches at the National Weather Service office in Rome...
Source: NOAA National Weather Service Storm Events Database.
Source: OpenFEMA NFIP Individual Claims (2.25M records analyzed).
FEMA assigns flood zone designations to areas in Grundy 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.
Properties in Grundy 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.