1,575 flood insurance claims·$49.8M 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 New Castle County, Delaware. 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 heavy rainfall and summer thunderstorms dominates the flood profile of New Castle County, Delaware. Over the last 30 years, NOAA records show 156 flash flood events resulting in 4 deaths, alongside 96 general flood events, 25 coastal flood events, 10 storm surge or tide events, and 3 tropical storms. Typical of this pattern, stationary fronts sparked showers and thunderstorms that caused flash flooding in July 2025.
National Flood Insurance Program records indicate that flood risks extend beyond high-risk areas, with claims filed across multiple zones. Properties in high-risk Zone A experienced 1,055 claims with an average payout of $50,266 and an average recorded water depth of 11 inches. Meanwhile, properties in Zone X recorded 314 claims averaging $22,762 with an average water depth of 15 inches, unshaded Zone X recorded 106 claims averaging $26,929 with an average water depth of 4 inches, shaded Zone X recorded 61 claims averaging $26,650 with an average water depth of 9 inches, and Zone D recorded 24 claims averaging $5,780 with an average water depth of 2 inches.
Homeowners, real estate agents, and journalists should pay the closest attention to properties located in Zone A due to the high volume of claims and payout amounts, as well as properties in Zone X where average recorded water depths during floods reached up to 15 inches.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
14% of New Castle County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
1,229 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 11 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 2003, with 263 claims and $16.3M paid, the year of Tropical Storm Henri and Hurricane Isabel.
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.
31 NOAA storm reports from New Castle County describe what happened, in the words of the forecasters who covered it. Read the Delaware flood stories →
17 federal disaster declarations since 1965, 6 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Remnants Of Hurricane Ida | Sep 1, 2021 |
| Tropical Storm Isaias | Aug 4, 2020 |
| Hurricane Sandy | Oct 27, 2012 |
| Hurricane Irene | Aug 26, 2011 |
| Severe Winter Storms And Snowstorms | Feb 5, 2010 |
| Hurricane Katrina Evacuation | Aug 29, 2005 |
| Severe Storms, Tornadoes, And Flooding From The Remnants Of | Sep 28, 2004 |
| Hurricane Isabel | Sep 18, 2003 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
290 since 1996: 156 flash floods, 96 river or area floods and 35 coastal floods or surges.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | Jul 31, 2025 | $10,000 |
| Flash Flood | Jul 31, 2025 | — |
| Flash Flood | May 30, 2025 | — |
| Flash Flood | Jul 9, 2025 | — |
| Flash Flood | Jul 9, 2025 | $50,000 |
| Flash Flood | Jul 9, 2025 | $20,000 |
| Coastal Flood | Apr 11, 2024 | — |
| Coastal Flood | Jan 10, 2024 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flash Flood · Jul 31, 2025. A stationary front sparked off showers and thunderstorms across the forecast area. Flash flooding resulted.
Flash Flood · May 30, 2025. Thunderstorms, in the vicinity a cold front, produced flash flooding.
Flash Flood · Jul 9, 2025. A slow-moving cold front produced heavy rain and flash flooding across portions of the region.
Coastal Flood · Apr 11, 2024. High astronomical tides in addition to strong southerly flow resulted in higher water levels, mainly along the Delaware Bay and tidal Delaware River. However, some flooding was observed in the back bays as southerly flow prevented water from draining.
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 New Castle 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.