Dorchester County Disaster Risk

Dorchester County has a FEMA National Risk Index rating of Relatively Moderate, placing it in the 94th percentile nationally out of 3,144 counties. This composite score reflects the county's overall exposure to natural hazards including floods, wildfires, tornadoes, earthquakes, and hurricanes, weighted by expected annual loss and social vulnerability.

Dorchester County is evaluated for five major natural hazard types: earthquake (98th percentile), hurricane (98th percentile), wildfire (79th percentile), flooding (79th percentile), tornado (75th percentile). The highest-risk hazard is earthquake at the 98th percentile nationally. These scores are derived from FEMA's National Risk Index, which analyzes expected annual loss, social vulnerability, and community resilience for each hazard type.

Dorchester County's composite risk percentile is 94th, compared to the South Carolina state average of 71th percentile. The state's overall risk rating is Relatively Low. This means Dorchester County faces higher natural disaster risk than the typical county in South Carolina.

Yes, Dorchester County's earthquake risk is at the 98th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Dorchester County is at the 79th percentile.

FEMA's National Risk Index (NRI) calculates risk scores for 18 natural hazard types across all U.S. counties and census tracts. The composite score combines Expected Annual Loss (estimated dollar losses from each hazard), Social Vulnerability (demographic factors affecting disaster impact), and Community Resilience (ability to recover). Percentile scores rank each county against all 3,144 U.S. counties, and risk ratings range from Very Low to Very High.

Dorchester County's composite risk score of 94th percentile is above the South Carolina state average of 71th percentile. This elevated risk is driven by earthquake exposure (98th percentile), along with hurricane and wildfire and flooding and tornado risk. Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.