Updated May 2026
Flood Risk in Marlboro, SC
Marlboro, SC has a Flood Risk Score of 16/100 (Grade A), ranking #461 of 3,277 counties nationwide. The risk level is Low. There have been 4 NFIP flood-insurance claims totaling $34,485 in payouts, with 16 federal disaster declarations on record.
Key Data
What the Grade Means Here
Marlboro sits in the lowest-risk tier in the FEMA dataset — composite score 16, ranked #461 of 3,277 counties (where #1 is the riskiest). The county has logged 4 NFIP flood-insurance claims and 16 federal flood-related disaster declarations to date. An A grade does not mean zero risk: flash floods, sewer backups, and rare extreme storms can still cause loss, and FEMA reports more than 25% of all NFIP payouts originate from properties outside Special Flood Hazard Areas.
Within South Carolina, Marlboro carries flood risk roughly typical of the state, where the average composite score is 14. The county ranks #11 of 47 state-internally. The full South Carolina state profile shows how every county within the state compares.
What's Driving the Risk Score?
The single biggest driver of the composite score in this county is federal disaster frequency (25% of the formula, factor score 34). For Marlboro, that means the cadence of federally declared flood-related disasters dominates — large enough events to exceed state and local response capacity have repeated multiple times.
The trend factor sits at 50 of 100 — a moderate signal that recent NFIP claim volume in this county has not been markedly worse than the long-run average. Watch for shifts after major storm seasons.
Score Breakdown
| Factor | Score | Weight |
|---|---|---|
| Claims Density | 0 | 40% |
| Disaster Frequency | 34 | 25% |
| Claim Severity | 0 | 20% |
| Year-over-Year Trend | 50 | 15% |
How This Score Is Calculated
The composite is a weighted average of four FEMA-derived factors. Source data comes from the public FEMA flood-mapping program via the OpenFEMA API. For property-level decisions, layer this with the parcel's FEMA Flood Insurance Rate Map zone and recent crest readings from USGS Water Data. Full math: methodology page.
Frequently Asked Questions
What is the flood risk in Marlboro, SC?
Marlboro, SC has a Flood Risk Score of 16/100 (Grade A), ranking #461 of 3,277 counties nationwide. The risk level is Low. There have been 4 NFIP flood-insurance claims totaling $34,485 in payouts, with 16 federal disaster declarations on record.
Is flood insurance required in Marlboro?
Federal law requires flood insurance for any property in a Special Flood Hazard Area (FEMA Zone A or V) financed by a federally regulated lender. Marlboro's county-wide composite score is 16 (Grade A), which is a county aggregate — your specific parcel's flood-zone designation comes from the FEMA Flood Insurance Rate Map (FIRM) at fema.gov/flood-maps. Even when not legally required, NFIP coverage is often available for a few hundred dollars a year in moderate- and low-risk zones, and FEMA reports more than 25% of all NFIP claims come from outside high-risk zones.
What is driving the flood risk score in Marlboro?
The single biggest driver of the composite score in this county is federal disaster frequency (25% of the formula, factor score 34). For Marlboro, that means the cadence of federally declared flood-related disasters dominates — large enough events to exceed state and local response capacity have repeated multiple times.
Is flood risk increasing or decreasing in Marlboro?
The trend factor sits at 50 of 100 — a moderate signal that recent NFIP claim volume in this county has not been markedly worse than the long-run average. Watch for shifts after major storm seasons.
How does Marlboro compare to other counties in South Carolina?
Within South Carolina, Marlboro carries flood risk roughly typical of the state, where the average composite score is 14. The county ranks #11 of 47 state-internally.
Where does this data come from?
Every figure on this page comes from FEMA's public OpenFEMA API — the DisasterDeclarationsSummaries v2 endpoint (federally declared flood-related disasters) and the FimaNfipClaims endpoint (individual NFIP flood-insurance claims aggregated by county FIPS code). Both are public-domain U.S. government work. Real-time stream-gauge readings that complement these federal aggregates live at USGS Water Data. Last updated 2026-05-16.
Marlboro, SC has a Flood Risk Score of 16/100 (Grade A), ranking #461 of 3,277 counties nationwide. The risk level is Low. There have been 4 NFIP flood-insurance claims totaling $34,485 in payouts, with 16 federal disaster declarations on record.
The data source behind this answer is FEMA OpenFEMA datasets including the National Flood Hazard Layer and NFIP claims. Every figure on the page traces back to that source; the methodology page describes the inputs and the refresh cadence in full detail.
For readers turning this answer into action: cross-reference against the underlying FEMA OpenFEMA datasets including the National Flood Hazard Layer and NFIP claims record before acting on time-sensitive decisions. The site renders the data as it was published; subsequent revisions can shift the picture, and the live federal data is always the authoritative current reference.