Many tools that identify wildfire risks and hazards across the landscape assume that all houses and properties within a community have the same level of risk. However, there are often substantial differences across properties, such as building materials and distance to overgrown vegetation. Tools that don’t account for parcel-level risk cannot provide the details necessary for informing action on private property, such as maintaining defensible space, posting a visible address sign, or hardening a structure.
To provide practitioners with a practical method for assessing how wildfire risk varies between homes and within an entire community, the Wildfire Research (WiRē) team developed a rapid assessment (RA) that can be conducted by a visual inspection from the road. In the summer of 2019, Colorado’s Grand County Wildfire Council (GCWC) conducted a WiRē RA of the Columbine Lake community, with each house receiving a score, the sum of multiple risk factors. A year later, the East Troublesome Fire burned 23 of the 352 fully assessed homes. At the request of the GCWC, the WiRē team analyzed how the WiRē RA scores related to the fire’s impact on the home.
This retrospective analysis found that a home’s overall WiRē RA score did relate to whether it was destroyed. Additionally, many of the individual risk factors measured by the RA related to whether a home was destroyed, despite being measured at only a coarse scale (e.g., roofing materials were evaluated for flammability, but their gutters were not). Risk factors crossed from properties to their neighbors, demonstrating that mitigation actions taken or not taken by a homeowner can affect neighboring homes. These findings support the use of the WiRē RA as an actionable complement to risk assessments conducted at broader scales. The WiRē RA provides useful information needed by practitioners to offer more targeted recommendations and support programs for homeowners to reduce their risk (e.g., maintaining defensible space and hardening structures to wildfire).