AI can show where wildfire risk is greatest in Colorado
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Homes and property torched in the Aspen Acres Fire in Colorado City. Photo: RJ Sangosti/Denver Post via Getty Images
Colorado is now requiring wildfire-prone communities to adopt new building and property standards — and an AI analysis, exclusively shared with Axios, shows how much work remains.
Why it matters: The updated rules are designed to prevent fast-moving wildfires like the 2021 Marshall Fire by building a buffer zone from trees and other plants that can catch fire and spread embers.
Driving the news: In Jefferson County, for example, more than 50% of structures have tree canopy hanging over their roofs, according to a report from Colorado-based Vexcel, a data analysis firm.
- 78% of the roughly 255,000 structures analyzed in the county have trees within 5 feet — considered the most critical buffer for defensible space to reduce ember ignition and direct flame contact.
Threat level: The proportion of homes at risk "can definitely be eye-opening," said Ford Freyberg, a Vexcel product manager based in Denver.
Zoom in: Even though wildfire risk is lower in Denver, the city's homeowners are far from prepared.
- 53% of structures have trees overhanging rooflines.
- 76% of the 250,000 structures analyzed have trees within 5 feet, and 93% have other structures within the same space.
- 94% have vegetation within 30 feet, an important setback that can minimize the fire's intensity and ability to spread.
Meanwhile, El Paso County is better prepared. Just 34% of its structures have overhanging trees.
- 57% have trees within 5 feet of structures.
- 77% have no buffer from vegetation within 30 feet.
What they did: Vexcel — formerly owned by Microsoft — used its proprietary aerial images collected by fixed-wing aircraft and applied an AI algorithm to identify at-risk properties.
- By using planes, it provides a higher resolution than satellite imagery, allowing a more detailed analysis.
The big picture: Such an analysis is critical after Colorado began requiring wildfire-prone localities to implement baseline rules for new construction and substantial renovations. Local authorities can also make the rules more stringent.
- "I think these codes will save lives, I think they will save property, I think they will save people money," Crystal Lambert, Colorado's Wildfire Resiliency Code Board chair, told CPR.