779 flood insurance claims·$16.8M paid·8 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 Dorchester County, South Carolina. 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 severe thunderstorms and heavy rainfall dominates the local flood hazard profile in Dorchester County, South Carolina. Over the last 30 years, NOAA records show 62 flash flood events, alongside 17 tropical storms, 12 general floods, 5 tropical depressions, and 3 hurricanes. Recent activity includes heavy rainfall from a slow-moving cold front encountering deep moisture and moderate instability in August 2025.
Federal insurance data indicates that flood risks extend beyond traditional high-risk areas. Properties located in FEMA Zone A account for the highest volume of claims at 563, with an average payout of $29,938 and an average recorded water depth of 8 inches. Meanwhile, properties designated as Zone X recorded 161 claims with an average payout of $31,632 and an average recorded water depth of 11 inches. Additional claims are distributed across unshaded Zone X (28 claims, average payout of $7,280, average depth of 1 inch), unknown zones (21 claims, average payout of $7,154, average depth of 2 inches), and shaded Zone X (4 claims, average payout of $15,724, average depth of 3 inches).
Homeowners, real estate agents, and journalists should pay the closest attention to properties located within Zone A and Zone X, as both areas account for the vast majority of historical flood insurance claims and significant average water depths during flood events.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
5% of Dorchester County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
597 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 8 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 2015, with 387 claims and $8.7M paid, the year of Severe Storms and 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.
39 NOAA storm reports from Dorchester County describe what happened, in the words of the forecasters who covered it. Read the South Carolina flood stories →
26 federal disaster declarations since 1989, 8 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Winter Storm | Jan 21, 2026 |
| Hurricane Helene | Sep 25, 2024 |
| Hurricane Debby | Aug 4, 2024 |
| Tropical Storm Debby | Aug 4, 2024 |
| Hurricane Idalia | Aug 29, 2023 |
| Hurricane Ian | Sep 25, 2022 |
| Hurricane Dorian | Aug 31, 2019 |
| Hurricane Florence | Sep 8, 2018 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
99 since 1996: 62 flash floods and 12 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | Aug 22, 2025 | — |
| Flash Flood | Aug 16, 2025 | — |
| Tropical Storm | Sep 26, 2024 | $303,000 |
| Flash Flood | Aug 9, 2024 | $60,000 |
| Flash Flood | Aug 9, 2024 | — |
| Flash Flood | Aug 9, 2024 | $20,000 |
| Flash Flood | Aug 6, 2024 | $20,000 |
| Flash Flood | Aug 6, 2024 | $10,000 |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flash Flood · Aug 22, 2025. A slow moving cold front encountering an environment displaying deep moisture and moderate instability supported thunderstorms capable of heavy rainfall across Southeast South Carolina.
Flash Flood · Aug 16, 2025. A weak cold front encountering deep moisture led to slow moving thunderstorms capable of producing heavy rainfall across Southeast South Carolina.
Tropical Storm · Sep 26, 2024. Helene first developed into a tropical storm in the northwest Caribbean Sea in the late morning of September 24, and strengthened into a hurricane near the Yucatan peninsula about 24 hours later. Helene continued to strengthen and became a major hurricane as it moved to the north-northeast across the eastern Gulf of Mexico. Helene made landfall in the Big Bend region of Florida in the late evening hours of Septemb…
Flash Flood · Aug 9, 2024. Debby first developed into a tropical storm about 100 miles west-southwest of Key West, Florida late afternoon on August 3rd, then gradually strengthened to a strong tropical storm while tracking north across the eastern Gulf of Mexico on August 4th. Debby then reached hurricane force strength late on August 4th about 100 miles west-northwest of Tampa, before continuing a north-northeast track across the eastern G…
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 Dorchester 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.