Environmental Risk Score

What Is the Environmental Risk Score?

The Environmental Risk Score measures a county's exposure to natural hazards and environmental quality concerns — including flood zones, wildfire risk, air quality, severe weather frequency, and industrial pollution. It helps property buyers and investors understand environmental risks that could affect property values and quality of life.

Key Metrics

• Flood Zone Exposure: Percentage of the county's land area within FEMA-designated flood zones.
• Wildfire Risk: The county's wildfire hazard potential, sourced from USGS and state fire agencies.
• Air Quality Index (AQI): Average air quality readings from EPA monitoring stations.
• Superfund Sites: Number of EPA Superfund or brownfield sites in the county.
• Severe Weather Frequency: Historical counts of tornadoes, hurricanes, and severe storms.
• Environmental Risk Score: A composite 0 to 100 index where higher scores indicate greater environmental risk.

Primary Data Sources

Environmental data is sourced from the FEMA National Flood Hazard Layer for flood zones, USGS and state fire agencies for wildfire risk, the EPA Air Quality System for air quality, and NOAA's Storm Prediction Center for severe weather history. The EPA Superfund and Brownfields databases track contaminated sites. CountyFlow aggregates these datasets to produce a composite Environmental Risk Score.

How to Use It

Property buyers use the Environmental Risk Score to understand natural hazard exposure before purchasing. High flood zone exposure may require flood insurance, which affects total housing costs. Wildfire risk affects insurance availability and premiums. Investors use the score to factor environmental risks into property valuations. Homeowners use it to understand long-term quality of life and resiliency concerns.

Methodology Notes

The Environmental Risk Score combines normalized sub-scores for flood exposure, wildfire risk, air quality, and severe weather frequency into a 0 to 100 composite. Flood zone data reflects FEMA's most recent National Flood Hazard Layer update. Air quality uses the annual average AQI from the nearest monitoring station. Counties without air quality monitors use regional estimates and are flagged accordingly.