61 flood insurance claims·$1.4M paid·7 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 Mercer 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.
River overflow and standard floods dominate Mercer County, accounting for 42 recorded events compared to 13 flash flood events over the last 30 years. Local flood risks are driven by seasonal conditions, such as significant Mississippi River flooding in April 2023 caused by record winter snowfall, frozen ground, rapid snowmelt, and saturated soils in Minnesota and Wisconsin. Additionally, heavy local and regional rainfall in July 2024 prolonged river crests and delayed the Mississippi River from falling below flood stage.
National Flood Insurance Program records indicate claims span multiple zones. Zone A properties experienced 47 claims with an average payout of $26,455 and an average recorded water depth of 32 inches. Zone X properties recorded 6 claims with an average payout of $24,860 and an average recorded water depth of 88 inches. Zone UNKNOWN recorded 4 claims with an average payout of $15,447 and an average water depth of 0 inches. Zone X_SHADED recorded 2 claims with an average payout of $15,810 and an average water depth of 12 inches, while Zone X_UNSHADED recorded 2 claims with an average payout of $1,493 and an average water depth of 11 inches.
Properties near rivers and those located in Zone A and Zone X should pay the most attention to flood risk, given the frequency of river flooding and the recorded claim payouts and water depths in these areas.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
8% of Mercer County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
51 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 33 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 32 claims and $768,970 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.
19 NOAA storm reports from Mercer County describe what happened, in the words of the forecasters who covered it. Read the Illinois flood stories →
15 federal disaster declarations since 1965, 7 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Storms And Flooding | Feb 24, 2019 |
| Severe Storms, Straight-line Winds, And Flooding | Apr 16, 2013 |
| Severe Winter Storm And Snowstorm | Jan 31, 2011 |
| Severe Storms And Flooding | Jun 1, 2008 |
| Hurricane Katrina Evacuation | Aug 29, 2005 |
| Flooding | Apr 18, 2001 |
| Winter Storm 1/1/99 | Jan 1, 1999 |
| Severe Storms & Flooding | Apr 13, 1993 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
55 since 1996: 13 flash floods and 42 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | Jul 11, 2025 | — |
| Flood | Jul 2, 2024 | — |
| Flood | Apr 26, 2023 | — |
| Flash Flood | Aug 31, 2021 | — |
| Flood | Apr 26, 2019 | — |
| Flood | May 21, 2019 | — |
| Flood | May 20, 2019 | — |
| Flood | Mar 16, 2019 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flash Flood · Jul 11, 2025. On July 11th, a line of severe thunderstorms moved across eastern Iowa and into northwest Illinois. These storms produced damaging straight-line winds and very heavy rain. Rainfall totals of 2 to 4 inches fell in a few hours across the Quad Cities, on top of heavy rain from the previous night and caused flash flooding in Moline and Bureau County. A Considerable Flash Flood warning was issued at 5:26 PM followed b…
Flood · Jul 2, 2024. Rain that fell during the month of June across Minnesota and Wisconsin caused rises on the Mississippi River, along the Iowa and Illinois border. Additionally, heavy rain that fell locally in July helped to prolong the crest and delay the river falling below flood stage, especially south of the Wapsipinicon, Rock, and Iowa Rivers.
Flood · Apr 26, 2023. Significant flooding occurred on the mainstem Mississippi largely due to the record snowfall this winter in Minnesota and Wisconsin, frozen ground, rapid snowmelt during the middle of April, and saturated soils. Major flooding was observed at all sites along the Mississippi north of Keokuk Iowa and most sites saw one of their top 10 crests on record.|This flooding had numerous impacts, with many roads, businesses…
Flash Flood · Aug 31, 2021. A cluster of slow moving storms formed the afternoon of August 31st in northwest Illinois. These dropped 1 to 4 1/2 inches of rain in a short period of time.
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 Mercer 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.