452 flood insurance claims·$3.1M 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 Mason County, Illinois. 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.
Flash flooding from summer thunderstorms dominates the flood risk profile in Mason County, Illinois, supported by 18 recorded flash flood events compared to 10 general flood events over the last 30 years.
Severe weather events have historically driven significant flooding impacts across the region. For example, a slow-moving isolated thunderstorm dropped 1 to 2 inches of rain in a short amount of time, producing flash flooding in the Illinois River Valley on July 9, 2020. Additionally, heavy rainfall from April 29 to April 30, 2017, dropped 2.00 to 6.50 inches of rain on saturated soils, causing flash flooding, widespread areal flooding, and numerous road closures.
Federal insurance claims data indicates that property owners in FEMA Zone A should pay the most attention, accounting for 193 claims with an average payout of $10,611 and an average recorded water depth of 14 inches. Residents in Zone X_SHADED also face notable risks, averaging 24 inches of recorded water depth across 4 claims with an average payout of $16,411, while unshaded Zone X and Zone X_UNSHADED properties have experienced hundreds of claims with average water depths of 5 inches.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
42% of Mason County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
330 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 10 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 147 claims and $499,688 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.
9 NOAA storm reports from Mason County describe what happened, in the words of the forecasters who covered it. Read the Illinois flood stories →
18 federal disaster declarations since 1968, 6 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Storms, Straight-line Winds, And Flooding | Apr 16, 2013 |
| Severe Winter Storm And Snowstorm | Jan 31, 2011 |
| Snow | Nov 30, 2006 |
| Hurricane Katrina Evacuation | Aug 29, 2005 |
| Severe Storms, Tornadoes, And Flooding | May 6, 2003 |
| Severe Storms, Tornadoes And Flooding | Apr 21, 2002 |
| Winter Storm 1/1/99 | Jan 1, 1999 |
| Severe Storms And Flooding | May 15, 1995 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
28 since 1996: 18 flash floods and 10 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | Feb 22, 2023 | — |
| Flash Flood | Jul 9, 2020 | — |
| Flood | Apr 29, 2017 | — |
| Flash Flood | Apr 29, 2017 | — |
| Flash Flood | Aug 12, 2016 | — |
| Flash Flood | Jun 28, 2015 | — |
| Flash Flood | Jun 26, 2015 | — |
| Flash Flood | Jun 7, 2015 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flash Flood · Feb 22, 2023. A warm front draped along the I-72 corridor served as the initial focusing mechanism for convection across central Illinois on February 22nd. Midday temperatures ranged from the upper 30s north of the boundary in the Peoria area to the lower 70s along and south of I-70. An upper-level disturbance interacting with the sharp temperature gradient triggered clusters of strong to severe thunderstorms during the late…
Flash Flood · Jul 9, 2020. A slow-moving isolated thunderstorm dropped 1 to 2 inches of rain in a short amount of time across northeast Champaign County during the late afternoon of July 9th, leading to widespread flash flooding in Rantoul. Meanwhile further west, a line of strong to severe thunderstorms developed along the Mississippi River ahead of an approaching cold front. These storms pushed into the Illinois River Valley, producing…
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 flooding in a…
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 damage. A downburst w…
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 Mason 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.