2,432 flood insurance claims·$48.4M 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 Mercer County, New Jersey. 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 and severe weather dominates the flood history of Mercer County, accounting for 74 events and two deaths over the last 30 years, alongside 51 standard flood events resulting in an additional two deaths. Recent NOAA records illustrate these hazards, including a flash flood event on August 6, 2024, driven by a humid, unstable airmass and predecessor rainfall ahead of Tropical Storm Debby, as well as coastal and tidal flooding along the Delaware River on January 10, 2024, caused by strong southerly winds combined with two to four inches of rainfall.
National Flood Insurance Program records show the heaviest claim volume concentrated in high-risk areas, with Zone A recording 1,643 claims with an average payout of $23,389 and an average recorded water depth of 21 inches. Moderate and minimal-risk areas also experience significant financial impacts; Zone X recorded 273 claims with an average payout of $48,408 and an average recorded water depth of 13 inches, while unshaded Zone X areas logged 287 claims averaging $30,069 with an average depth of 8 inches.
Homeowners in Zone A face the highest frequency and deepest average water levels, while property owners in shaded and unshaded Zone X areas must also pay close attention, as they experience substantial average payouts and flood depths despite being outside traditional high-risk zones.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
19% of Mercer County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
2,028 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 17 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 2011, with 408 claims and $15.1M paid, the year of Hurricane Irene and Remnants Of Tropical Storm Lee.
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.
26 NOAA storm reports from Mercer County describe what happened, in the words of the forecasters who covered it. Read the New Jersey flood stories →
28 federal disaster declarations since 1965, 6 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Remnants Of Hurricane Ida | Sep 1, 2021 |
| Severe Winter Storm And Snowstorm | Jan 22, 2016 |
| Hurricane Sandy | Oct 26, 2012 |
| Remnants Of Tropical Storm Lee | Sep 28, 2011 |
| Hurricane Irene | Aug 27, 2011 |
| Severe Winter Storm And Snowstorm | Dec 26, 2010 |
| Severe Storms And Flooding | Mar 12, 2010 |
| Severe Storms And Inland And Coastal Flooding | Apr 14, 2007 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
139 since 1996: 74 flash floods, 51 river or area floods and 11 coastal floods or surges.
| Event | Date | Damage |
|---|---|---|
| Coastal Flood | Jan 10, 2024 | — |
| Flash Flood | Aug 6, 2024 | $40,000 |
| Flash Flood | Aug 6, 2024 | — |
| Coastal Flood | Apr 4, 2024 | — |
| Coastal Flood | Dec 18, 2023 | — |
| Flash Flood | Jul 15, 2023 | — |
| Coastal Flood | Dec 23, 2022 | — |
| Coastal Flood | Oct 29, 2021 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Coastal Flood · Jan 10, 2024. A strong system affected the region with steady southerly flow pushing water up into coastal communities both along the ocean and within the Delaware River/Bay and Chesapeake Bay. Water levels on the tidal Delaware River were higher due to 2 to 4+ inches of rainfall.
Flash Flood · Aug 6, 2024. A predecessor rainfall event set up ahead of the remnants of Tropical Storm Debby. A hot and humid airmass was in place, resulting in a very moist and unstable airmass. A few showers and thunderstorms developed, producing damaging wind gusts across portions of New Jersey, downing trees and wires.
Coastal Flood · Apr 4, 2024. Strong onshore flow with a potent storm moving up the NJ/Delaware coast resulted in water piling up along the New Jersey coast and within the back bays. Water also moved up the Delaware Bay, which also resulted in tidal flooding within the Delaware River.
Coastal Flood · Dec 18, 2023. An area of low pressure passing over the region resulted in strong onshore flow and a push of water onshore and up the Delaware Bay and Delaware River, where moderate coastal flooding was observed.
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.