WASHINGTON, D.C. – The U.S. Department of Commerce issued a report Saturday concerning the Camp Fire that destroyed more than 18,804 structures on Nov. 8, 2018, causing the deaths of 85 residents of Butte County.
The National Institute of Standards and Technology (NIST) report called, “A Case Study of the Camp Fire – Fire Progression Timeline,” was authored by NIST and representatives from the United States Forest Service, CAL FIRE, the University of Washington, and the University of Maryland.
According to the report, it took approximately six hours for the Camp Fire to consume a “significant fraction” of the Town of Paradise. It also caused considerable damage in Magalia, Concow, and other Highway 70 communities, and in Butte Creek Canyon.
In the report, the Camp Fire was reference as the most destructive and deadly fire in California history.
The 421-page in-depth case study was created to increase understanding of wildland-urban interface (WUI) fire spread, fire behavior, evacuation, and structure response. More than 2200 observations about the Camp Fire’s spread and behavior were collected during the case study.
In reference to fire danger in WUI areas, in the report it is states that, "In the United States, over 44 million homes, housing 32 % of the US population, were in the WUI in 2010. In the early 2000s, over one thousand structures per year on average were lost to WUI fires in California alone. The WUI fire problem is growing nationally each year; in the 2010s, multiple single fire events have caused losses in the thousands of structures."
According to the study’s authors, the Town of Paradise and the County of Butte were “well prepared to respond to a WUI (wildland-urban interface) fire.” This was a major finding in the report.
Here is a conclusion from the report concerning the preparedness of entities in the Butte County WUI: “This study has identified that Butte County and the Town of Paradise were well prepared to respond to a WUI fire, that the Camp Fire grew and spread rapidly and that multiple factors contributed to the rapid growth and spread of the Camp Fire. Additionally, this study identified the importance of the wildland fire ignition location relative to the community, that multiple parcel-level fire spread pathways caused structure ignitions, and that WUI fire spread impacted the affected communities in multiple ways beyond the destruction of residential and commercial properties.”
Extreme winds of 50 mph, dry vegetation, and long-range spotting of a distance of almost four miles were identified as contributing factors to the damage and destruction caused by the Camp Fire.
The dry vegetation was blamed upon a period of 200 days without any significant precipitation, which authors said increased the fuel ignition potential around and within Concow, Paradise, and Magalia.
The fire spread rates for Paradise and Magalia could not be “readily computed,” according to the authors, due to extensive spotting fire behavior. The fire traveled and spotted more than seven miles downwind of its origin in Pulga in the Feather River Canyon, reaching the Town of Paradise in less than 1.5 hours.
Though the communities and the County were found to be well-prepared for prompt evacuations, “burnovers” were identified as the major reason civilian evacuations and first responder operations were so greatly hindered.
The definition of a “burnover,” according to the National Wildfire Coordinating Group (NWCG), is an event in which a fire moves through a location or overtakes personnel or equipment where there is no opportunity to utilize escape routes and safety zones, often resulting in personal injury or equipment damage.
The report's findings revealed that there were multiple burnovers during the Camp Fire, which adversely affected pre-planned evacuation routes and led to the use of Temporary Refuge Areas (TRAs).
One of the recommendations in the report is an urging to characterize fire behavior that leads to burnovers and to quantify burnover severity. Authors say this information would help to inform fuel setback guidance for primary egress arteries and provide technical input necessary for community evacuation plans.
The intense vegetation and structure fires along roadways, along with downed utility poles, resulted in multiple road closures which adversely impacted response and evacuation activities.
The fire spread from parcel to parcel was fueled by vegetation, including ornamental shrubs, bushes, and trees; structural fuels, including homes, garages, detached auxiliary buildings, commercial occupancies; and cars, trucks, and campers.
It was discovered that the separation distances in the WUI between fuel packages within an individual parcel and between parcels were not sufficient enough to prevent rapid fire spread.
The newly released report utilized post-fire field data and first responder observations to identify structure ignition vulnerabilities including a close look at structure-to-structure ignition pathways.
A recommendation in the report states that a standardized community WUI hazard evaluation framework would improve the assessment of fire risk for communities.
Here are nine recommendations from the NIST report:
- Characterize fire behavior that leads to burnovers and quantify burnover severity (This information will inform fuel setback guidance for primary egress arteries and provide technical input to evacuation plans)
- Develop technical guidance to quantify parcel-level exposures
- Quantify fire spread within parcels with a focus on fire exposures
- Quantify exposures from adjacent parcels, specifically from neighboring structures, and develop design guidance for structure separation distances
- Develop a methodology to connect field-collected ember-data, such as ember flux and size distribution, to laboratory scales and develop worst-case ember exposure criteria
- Develop spacing/hardening cost-benefit relationships for high energy release sources (fences, woodpiles, sheds, vehicles, RVs, and residences) and target structures (residential and commercial)
- Characterize the relationships among fire history, fuel treatments, and fire behavior
- Develop a standardized methodology for assessing the exposures from ornamental vegetation
- Develop a plant list for vegetation with unacceptably high fire hazard for northern California and other locations with wildland-urban interface fire risks
The full report is available online here.