Report: wildfires pose risk to nearly 900,000 homes in the western U.S.

Whoopup Fire house threatened
Homes were threatened by the Whoopup Fire east of Newcastle, Wyoming, July 18, 2011. Photo by Bill Gabbert.

From CoreLogic:

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.

The CoreLogic Wildfire Risk analysis designates risk levels as “Very High,” “High,” “Moderate” and “Low.” Two additional categories, “Urban” and “Agriculture” indicate homes at even lower risk. Homes designated as “Urban” are located in areas with a dense concentration of buildings and infrastructure to such an extent that little natural vegetation exists to support a wildfire. Homes designated as “Agriculture” are located in areas comprised of row crops, orchards/vineyards or other specific land use that is typically irrigated. Even if it is not irrigated, the crops are nourished and healthy with no ground litter present, and therefore, the vegetation is unlikely to support or enhance a wildfire.

The analysis also assigns a numeric risk score to each property, ranging from 1 to 100. This separate score indicates the level of susceptibility to wildfire, as well as the risk associated with the property being located in close proximity to another high-risk property or area. The score designation is important since wildfire can easily expand to adjacent properties and cause significant damage even if that property was not originally considered high risk. When expanding the analysis to include the numeric score, more than 1.1 million homes fall under the highest Wildfire Risk Score segment (81-100), representing a combined potential reconstruction value of more than $268.5 billion

Total U.S. Properties at Risk and Reconstruction Values by Risk Category

Wildfire Risk LevelTotal PropertiesReconstruction Cost
Very High192,242$49,608,484,867
High704,860$187,661,388,760
Moderate1,351,313$292,811,373,342
Low1,378,104$334,120,053,463
Agriculture993,580$244,167,729,666
Urban23,778,799$6,094,873,170,789
Total:28,398,898$7,203,242,200,887

Total U.S. Properties at Risk and Reconstruction Values by Numeric Risk Score

(1-100)Total PropertiesReconstruction Cost
81-1001,101,131$268,549,008,333
61-801,193,814$338,395,410,748
51-60487,013$131,081,392,801
1-5025,616,940$6,465,216,389,005
Total:28,398,898$7,203,242,200,887

The states most commonly associated with wildfires also contain the most properties at risk – 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

StateLowModerateHighVery HighAgricultureUrbanTotal
AZ43,2734,4438,4888,0895,3321,910,7711,980,396
CA221,104169,468255,02350,905146,0138,208,6259,051,138
CO70,93538,62850,00949,66766,8761,482,3521,758,467
ID37,35222,96815,19711,07886,542384,018557,155
MT60,58818,9039,60110,21822,516194,927316,753
NV17,84520,5208,6532813,166816,975867,440
NM55,96919,55425,7669,48116,200483,282610,252
OK165,00988,642187033,225968,2101,255,273
OR37,13741,16051,87213,788157,749938,6641,240,370
TX332,766829,457261,85535,016175,6915,960,2217,595,006
UT11,18513,5903,4416831,825681,016741,125
WA308,06672,06912,5091,997219,3341,625,3942,239,369
WY16,87511,9112,2591,65429,111124,344186,154
Total1,378,1041,351,313704,860192,242993,58023,778,79928,398,898

Total Properties at Risk by State and Numerical Risk Score

State1-5051-6061-8081-100Total
AZ1,919,35114,30827,15919,5781,980,396
CA8,286,708133,654367,457263,3199,051,138
CO1,454,78752,823122,509128,3481,758,467
ID476,3109,55427,86843,423557,155
MT243,99013,11427,30132,348316,753
NV848,6822,3379,1847,237867,440
NM523,75514,48732,13939,871610,252
OK1,250,8881,4312,2197351,255,273
OR1,091,30022,61646,65579,7991,240,370
TX6,458,363197,548487,247451,8487,595,006
UT693,25614,71324,3118,845741,125
WA2,192,5678,66217,00121,1392,239,369
WY176,9831,7662,7644,641186,154
Total25,616,940487,0131,193,8141,101,13128,398,898

Reconstruction Values by State and Numerical Risk Score

State1-5051-6061-8081-100
AZ$369,191,090,202$2,781,562,044$5,612,822,008$4,002,789,607
CA$2,785,871,424,591$53,258,974,686$153,067,995,013$88,448,970,333
CO$333,552,521,110$13,769,558,737$33,846,313,158$36,107,351,913
ID$102,894,072,845$2,426,687,082$6,899,872,812$10,300,994,948
MT$52,685,950,526$2,997,541,855$6,338,603,322$7,639,941,924
NV$216,436,292,731$624,126,373$3,860,921,144$3,188,829,537
NM$105,891,175,664$3,334,262,905$7,919,619,903$10,468,473,653
OK$230,716,181,496$235,452,854$370,084,424$124,431,936
OR$248,596,738,298$5,247,235,235$11,061,921,922$18,192,420,905
TX$1,276,614,038,497$39,753,699,730$97,535,512,589$82,027,014,100
UT$159,359,659,455$4,309,214,977$7,363,299,947$2,115,609,007
WA$547,066,785,312$1,964,631,216$3,905,374,051$4,938,186,894
WY$36,340,458,278$378,445,107$613,070,455$993,993,576
Total$6,465,216,389,005$131,081,392,801$338,395,410,748$268,549,008,333

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

CBSAVery High # HomesHome Reconstruction Value
Denver-Aurora-Lakewood, CO17,860$5,358,513,217
Riverside-San Bernardino-Ontario, CA14,249$4,233,998,840
Sacramento-Roseville-Arden-Arcade, CA9,698$3,351,781,562
Bend-Redmond, OR9,128$2,328,466,791
Colorado Springs, CO7,296$2,086,189,220
Durango, CO6,052$1,776,710,340
Fort Collins, CO4,609$903,336,600
Truckee-Grass Valley, CA4,569$1,430,020,245
Houston-The Woodlands-Sugar Land, TX4,219$917,157,644
Flagstaff, AZ4,109$753,176,500

Top 10 CBSAs Ranked by Numerical Risk Score

CBSA81-100 Risk ScoreHome Reconstruction Value
Riverside-San Bernardino-Ontario, CA50,605$14,805,549,511
Sacramento–Roseville–Arden-Arcade, CA42,042$15,875,023,943
Austin-Round Rock, TX35,807$9,019,956,767
Denver-Aurora-Lakewood, CO35,174$10,807,628,461
San Antonio-New Braunfels, TX31,350$7,097,211,479
Los Angeles-Long Beach-Anaheim, CA17,006$8,654,562,030
Chico, CA15,103$3,754,593,902
Colorado Springs, CO14,990$4,408,080,237
Truckee-Grass Valley, CA14,671$4,945,547,724
Houston-The Woodlands-Sugar Land, TX14,092$3,063,417,604

*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.

Author: Bill Gabbert

After working full time in wildland fire for 33 years, he continues to learn, and strives to be a Student of Fire. Google+

2 thoughts on “Report: wildfires pose risk to nearly 900,000 homes in the western U.S.”

  1. I would be interested to see the criteria they used for determining the category, which seems to describe hazard within the property line, and hazard scale, which seems to be based outside the property line. They mentioned specifically the potential hazard of fire brands being generated from vegetation fuels.

  2. With any large assessment the devil is in the details. The fact that their maps shows all of Oregon except the Willamette valley as at “High-Very High” risk of wildfire raise some questions. I wish they included some detail on their methods in the report.

Comments are closed.