Susan Smith has worked as an editor and writer in the technology industry for over 16 years. As an editor she has been responsible for the launch of a number of technology trade publications, both in print and online. Currently, Susan is the Editor of GISCafe and AECCafe, as well as those sites’ … More »
CoreLogic Wildfire Risk Analysis Data Pinpoints High Risk Areas in the U.S.
April 2nd, 2015 by Susan Smith
CoreLogic recently released new wildfire data, the CoreLogic Wildfire Risk Analysis, that states that nearly 900,000 single-family homes across 13 states in the western U.S. are currently designated at “High” or “Very High,” risk for wildfire damage, representing a combined total reconstruction value estimated at more than $237 billion. Of the total homes identified, just over 192,000 homes fall into the “Very High Risk” category alone, with total reconstruction cost valued at more than $49.6 billion. Other categories include “Moderate” and “Low” risk. GISCafe spoke with Dr. Tom Jeffery of CoreLogic to find out the scoop on this important new information for homeowners, insurance companies and other stakeholders.
Dr. Tom Jeffery: In the past we used what’s called the assessed property value which is based on tax assessment. We’ve actually changed that so it matches what we do with storm surge which is reconstruction value of these homes. This is going to be the cost of labor and materials in each of the different locations to replace the structure that would be lost in the event that a wildfire destroyed the whole thing. California is right at the top of the list, in most cases, because of wildfire risk throughout the state, but Colorado and Texas are also states that are usually ranked very high. They continue to do so through this report. There is one overarching factor that pops out whenever we do these reports. When we see results for the first time, we see how many homes are at risk in the total U.S. and what those values are. They are exceptionally high in those areas.
GISCafe Voice: What determines what states are ranked high?
TJ: Because you have large population centers in California, Texas and Colorado, and those urban areas that continue to grow, the pace of the growth is going to grow from year. All three of those states continue to have urban expansion and new homes constructed continue to push out into areas that have higher risk. There’s a lot of risk in those three states as well. A lot of people and a lot of risk is a combination that put those three to the top of the list.
GISCafe Voice: How do you assess the risk score?
TJ: The risk score itself is really based on several factors we combine, the first is the risk on the property, and that determines our categories of high, moderate high and very high, those determine the risk on the property. It’s based on what fuel is there, based on vegetation, if there’s change of terrain, if there’s a steep slop which enhances the risk, that determines the category. But for the score we actually want to look outside the property boundary to risk in close proximity to that property. So if you own a property maybe you have a nice manicured lawn, decorative trees, you don’t have any risk on the property. But just outside the boundary there could be a lot of chaparall in Southern California, for instance, a dense conifer or pine forest, in other areas. If that exists really close to your property that raises the risk value.
So we measure the distance from a property to what’s around it in terms of risk and then we add that to the category or risk on the property, and we add that to the score. The score is going to be 0-100 numeric-based and anything that’s 80 and above is extremely high risk. We have those broken out in the tables, so you can see even though if you look at the U.S. as a whole, there are going to be 192,000 properties that are listed as very high. And that’s looking at the risk on the property. As soon as we look at the score – and the score 81-100, we go from 192,000 all the way up to 1.1 million. So really those homes on the urban edge pushing out in to the wilder areas are the ones that the score is picking up and that’s why the scores are jumping from 192,000 to 1.1 million. It’s the homes that don’t have the risk within their borders and boundaries but have it just outside that are at most risk.
GISCafe Voice: What are insurance companies concerned with when they consult with you?
TJ: Most of those discussions with insurance company representatives revolve around mitigation, which is, how can homeowners reduce the risk on the property and which properties need that? More and more insurance companies have to write these policies and there are so many high risk policies they can’t ignore. What they’re trying to do more and more is identify the high risk properties, then identify ways they can talk to land and homeowners and clear brush around the homes, make sure it’s not a wood shake roof, all these things do to reduce the risk on higher risk. It helps homeowner in the long run because it’s less risk for their home, also helps insurance companies so they both benefit from things homeowners can do to reduce risk on property.
GISCafe Voice: In looking at the properties, is one of the factors that you taking into account in terms reconstruction costs, the cost of the area in terms of real estate?
TJ: The reconstruction costs don’t factor in the costs of the land or the ground land sits on, it is the assessed value taken into account. We were looking at a better way to know what the risk is for the property owner and when we went to reconstruction costs, they have values that are different depending upon where you are geographically as you would expect. It may cost more in terms of labor and materials to build a home in parts of California as opposed to Idaho where labor and materials may be cheaper. All those geographic differences are factored into the cost. The cost of reconstructing a home in LA is going to be higher than doing it in Boise, Idaho.
Also, Montana, Idaho and Utah have a lot of risk, but they don’t have the population.
GISCafe Voice: Do you have your own geographic information system?
TJ: Yes, both of the models we use to create categories and the score are models we’ve created in house –proprietary information. We use GIS extensively to do modeling and run the values of the properties, etc.
From CoreLogic company materials:
Total U.S. Properties at Risk and Reconstruction Values by Risk Category
Total U.S. Properties at Risk and Reconstruction Values by Numeric Risk Score
The states most commonly associated with wildfires also contain the most properties at risk â“ California, Colorado and Texas have the largest number of residential properties categorized as “Very High Risk,” with a combined reconstruction value exceeding $36 billion. Including homes located in the “High Risk” category, the reconstruction value is more than $188 billion for these three states. When analyzed by risk score, 816,515 homes with reconstruction costs valued at more than $206.5 billion fall into the highest risk segment of 81-100.
Limiting the evaluation to property-level risk strictly in the “Very High” category, California tops the list of states analyzed with a total of 50,905 homes falling into that group. Comparatively, when assigning the Wildfire Risk Score, Texas takes the top spot with 451,848 homes scoring in the 81-100 highest-risk range.
Total Properties at Risk by State and Risk Category
Reconstruction Values by State and Risk Category
Total Properties at Risk by State and Numerical Risk Score
Reconstruction Values by State and Numerical Risk Score
At the CBSA (Core Based Statistical Area) level, Denver-Aurora-Lakewood, Colo. ranks first for the most number of homes at “Very High” risk out of the 258 CBSAs analyzed. Riverside-San Bernardino-Ontario, Calif. comes in a close second, followed by Sacramento-Roseville-Arden-Arcade, Calif.
When ranking CBSAs based on Wildfire Risk Score, Riverside-San-Bernardino-Ontario, Calif. takes the top spot for the most number of homes that fall under the highest risk segment of 81-100, followed by Sacramento-Roseville-Arden-Arcade, Calif. and Austin-Round Rock, Texas.
Top 10 CBSAs Ranked by Homes at Very High Risk
Top 10 CBSAs Ranked by Numerical Risk Score
*Additional CBSA-level data may be available upon request.
To enhance accuracy, this CoreLogic wildfire analysis has been expanded from prior annual analyses to encompass additional categories of single-family residential structures including mobile homes, duplexes, manufactured homes and cabins, among other non-traditional home types. The values represent estimates of reconstruction costs, taking into account labor and materials, and are based on 100-percent or total destruction of the residential structure. Depending upon the size of the wildfire, there may be less than 100-percent damage to the residence, which would result in a lower realized reconstruction cost.