Researchers document the effect of pre-fire mitigation on structure losses during 2017 Thomas Fire

Two decades of work in Montecito, California had a positive effect during the fire

Montecito, CA five-mile border with Los Padres National Forest
The northern edge of Montecito, CA shares a five-mile border with the Los Padres National Forest. Looking north. Google Earth/Wildfire Today. Click to enlarge.

In December, 2017 the Thomas Fire burned over 281,000 acres and 1,000 homes in Ventura and Santa Barbara Counties in Southern California. But in Montecito, with a wildland-urban interface stretching for five miles along the Los Padres National Forest boundary, only seven primary residences were destroyed. Considered a success story, this result is due to many factors, including the fact that homeowners and firefighters had days to prepare for the fire entering the city, which meant that firefighters did not have to make a choice between helping residents to evacuate or protecting homes. This is in stark contrast to last November’s Camp Fire that raced into Paradise, California within a couple of hours after being ignited by a PG&E power line. In that case firefighters did not have the luxury of suppressing the fire as it burned homes; they had to concentrate on helping residents evacuate and saving lives.

But another important factor that helped to reduce the number of homes destroyed in Montecito in 2017 was the pre-fire mitigation work that had been ongoing in the community for two decades.

After the fire the Montecito Fire Protection District sought to document and understand the confluence of social, ecological, and biophysical factors associated with implementing fire adaptation activities and how they affected the outcome of the Thomas Fire in their community.

The findings in this study should be considered by all communities in a fire-prone environment. Cities that resist mitigation efforts such as constructing fuel breaks, enacting FireWise building codes, spacing homes more than 10 to 20 feet apart, planning for evacuations, and being proactive in protecting their residents long before smoke is in the air, are doomed to a very unpleasant and rude awakening one day. It is not IF a fire will impact their community, it is WHEN.

Below are excerpts from the Montecito study, conducted by Crystal A. Kolden and Carol Henson. The entire report is open source.


Montecito wildfire vulnerability to fire embers
The Montecito Community Wildfire Protection Plan used fire modeling to geospatially characterize ember exposure and defensibility across the community with respect to structures, in order to prioritize key areas for future vulnerability reduction activities. (From the report)

…Here, we document both the social and the biophysical vulnerability reduction strategies taken by the community of Montecito, California in Santa Barbara County, USA, prior to the 2017 Thomas Fire, and how those strategies translated into outcomes. Montecito is one of the many communities in the United States that has been repeatedly exposed to wildfires over the last several decades, with multiple disastrous events . As such, the Montecito Fire Protection District (MFPD) embarked on an effort to reduce wildfire vulnerability in the community two decades ago. That effort was subsequently tested in the December 2017 Thomas Fire, which consumed over 1000 homes and became the largest wildfire in contemporary California history for several months until it was surpassed in 2018. Most of the homes were consumed at the outset of the Thomas Fire on days when strong downslope winds (i.e., Santa Ana and Sundowner winds) prevailed, and extreme fire behavior including long runs and long-range spotting, occurred, overwhelming fire suppression efforts. By contrast, Montecito experienced relatively little infrastructure damage from the Thomas Fire, despite similar conditions, including extreme fire behavior and the presence of Sundowner winds on the day the fire beset the community (16 December 2018).

Montecito Fire Protection District fuel treatment network
Montecito Fire Protection District fuel treatment network, homeowner defensible space, and locations of residences (both primary homes and guest houses) destroyed by the Thomas Fire in Montecito.

Over the 20-year period between 1999 and 2018, the MFPD expended approximately $1.76 million (mill) USD ($2 mill USD adjusted for inflation to 2018) on wildfire vulnerability reduction activities (Figure 2). We include 2018 here as these are fiscal year totals, where the fiscal year ends June 30 of the year listed, so the Fiscal Year 2018 (FY2018) expenditures were primarily expended in autumn 2017, prior to the December ignition of the Thomas Fire (this also contributes to reduced FY2018 expenditures relative to prior years). When adjusted for inflation, it is clear that funding was inter-annually variable, but generally increasing over time (Figure 2).

Most of the activities undertaken by MFPD addressed more than one component of the vulnerability triangle (i.e., exposure, sensitivity, and adaptive capacity).

  • Any action that specifically identified geospatial patterns of exposure to wildfire (e.g., defensible space surveys), or was designed to reduce direct exposure to wildfire (e.g., defensible space improvements, roadside fuel reduction) addressed exposure vulnerability.
  • Any action that specifically identified populations in the community that are more sensitive to the negative ramifications of wildfire and determined population-specific actions designed to mitigate those ramifications addressed sensitivity vulnerability.
  • Any action that increased the ability of the community to respond to wildfire and reduce the negative ramifications developed adaptive capacity.

An action such as hiring a Wildland Fire Specialist, whose primary position is to build relationships with community members and facilitate programs to reduce vulnerability, addressed all three components of vulnerability.

Evacuation and ingress/egress issues were key elements of two other activities undertaken by MFPD prior to 2017.

First, MFPD improved ingress/egress and evacuation and fire suppression effectiveness by delineating pre-attack zones across the community in their wildland fire initial attack plan. MFPD utilized these pre-attack zones (which are essentially sub-units of the community that were delineated prior to firefighters attacking a future, hypothetical wildfire) in their community education efforts, planning process, and printed high-resolution paper maps of each zone that were pre-packed in a portable file box for distribution to non-MFPD fire suppression resources in the event of a wildfire. Nine of the interviewees noted the utility of these maps in facilitating greater life safety for firefighters and increased suppression effectiveness, because the maps were able to help resources not familiar with the area to navigate the community safely and quickly and find the pre-designated water sources and equipment staging areas in Montecito, which were also marked on the map.

Second, while MFPD implemented several new fire codes focused specifically on structures (e.g., banning cedar shakes for roofing and siding, requiring boxed eaves), a new requirement for wider driveways focused on reducing exposure through improved evacuation, and increasing adaptive capacity by facilitating firefighter safety during fire suppression activities and post-fire clean up. In Montecito, as in many WUI communities, many of the homes are located at the end of long (>100 m), narrow, winding driveways that terminate at garages. Increasing driveway width and turnaround space supports larger fire apparatus and other large equipment allowed firefighters access these areas, and safely use a tactic referred to as “fire following.” Fire following is frequently used during extreme conditions, wherein firefighters (1) prepare homes to resist an oncoming wildfire, (2) retreat from the home or neighborhood when extreme fire behavior and direct flames from the fire front threaten their life safety, and then (3) “follow” behind the flaming front and re-engage with the home or in the neighborhood. During this re-engagement, they focus on extinguishing portions of the structure that are on fire, extinguishing spot fires on the property, remove flaming debris from structures (e.g., flaming palm fronds on the roof or deck), and wetting down vegetation if there are additional threats for re-ignition (e.g., additional spot fires). Fire following depends on firefighters being able to safely navigate to a home and turn around so that they can evacuate rapidly if needed; driveway design is paramount to this dependency.

The effectiveness of fire suppression efforts was directly supported by the pre-fire vulnerability reduction efforts undertaken by MFPD. Interviewees noted that they were able to use fire following tactics because homes were fire-resistant, giving firefighters time to engage and remove flammable debris before a structure became fully involved with fire. Firefighters also described being able to engage because most homes had sufficient defensible space to make it safe for them to do so, without fear of entrapment. This was of particular concern due to entrapment of firefighters that occurred on the nearby Jesusita Fire in 2009, which was associated with lack of defensible space and evacuation routes.

Interviewees also noted that suppression effectiveness was amplified by the reduction of roadside fuels, which allowed them to conduct backfiring operations along some parts of the road system and hold the fire along other segments. Interviewees described the difference between other portions of the Thomas Fire in Santa Barbara County, where heavy roadside vegetation created a “tunnel effect” that inhibited large fire apparatus passage (leading to over a dozen homes destroyed in one nearby canyon), and Montecito, where roadside clearance eliminated vegetation tunnels and facilitated two large city fire apparatus being able to pass each other on narrow roads. Videos taken by some interviewees further demonstrated how such clearance improved firefighter safety given the low visibility created by heavy smoke. Several firefighter fatalities in the US have been attributed to exiting the roadway due to lack of visibility in smoky conditions.

Both defensible space and roadside fuel treatments were supplemented by the community fuel treatments implemented by MFPD, which served to “link” together with the fuel reductions undertaken by residents and along roadways. All but one interviewee described this network of fuels reduction as being vital to effective suppression efforts and structure protection, specifically because it allowed firefighters to engage the fire safely. Of the seven primary residences destroyed in Montecito, two were located below a ‘gap’ in the fuel treatment network, and the loss of the remaining dwellings was primarily attributed to the presence of fuels immediately adjacent to the structure, and inaccessibility for firefighters to support the fire following tactic. These losses were attributed to fire exposure that was not mitigated.

Investigators determine that a power line caused the Thomas Fire

The fire burned 281,893 acres near Santa Barbara, destroyed 1,063 structures, and caused the death of one civilian and one firefighter

Thomas Fire
Thomas Fire, Ventura, CA, Los Padres National Forest, 2017. USFS photo.

The Ventura County Fire Department (VCFD) has determined that an arcing power line caused the Thomas Fire that destroyed 1,063 structures and caused the death of a civilian and a firefighter.

Investigators found that strong winds on December 4, 2017 forced Southern California Edison power lines to come in contact with each other, resulting in molten metal falling to the ground which ignited vegetation. The common term for this is “line slap.”

Measured east to west the Thomas Fire spread for over 42 miles, stretching between Fillmore and Santa Barbara in Southern California.

map Thomas Fire
Map of the west side of the Thomas Fire. The red line was the perimeter on December 23, 2017. Click to enlarge.

CAL FIRE Fire Apparatus Engineer Cory Iverson of the San Diego/San Diego County Fire Authority was overrun by fire and killed December 14, 2017 while battling the blaze. A 70-year-old woman died in a car accident while fleeing the fire on December 6, 2017.

At one point nearly 9,000 emergency personnel were working on the fire.

The investigative team was comprised of four agencies: CAL FIRE, Ventura County Sheriff’s Office, Santa Barbara County Fire Department, and the U.S. Forest Service.

Wildfires can be part of a series of cascading events

Maximum Wildfire Elevation
Maximum Wildfire Elevation. MBTS & Nature.

In the natural world one environmental event or disturbance can initiate or be part of a series of cascading events that intensify the impacts of natural hazards, possibly turning them into disasters.

An article at The Conversation explores how these effects can be enhanced by a warming climate. Below is an excerpt from an article written by Amir AghaKouchak (UC Irvine) and Farshid Vahedifard (Mississippi State University).


“Multiple hazardous events are considered cascading when they act as a series of toppling dominoes, such as flooding and landslides that occur after rain over wildfires. Cascading events may begin in small areas but can intensify and spread to influence larger areas.

[…]

“Also, the severity of these cascading weather events worsens in a warming world. Drought-stricken areas become more vulnerable to wildfires. And snow and ice are melting earlier, altering the timing of runoff. This has a direct relationship with the fact that the fire season across the globe has extended by 20 percent since the 1980s. Earlier snowmelt increases the chance of low flows in the dry season and can make forests and vegetation more vulnerable to fires.

“These links spread further as wildfires occur at elevations never imagined before. As fires destroy the forest canopy on high mountain ranges, the way snow accumulates is altered. Snow melts faster because soot deposited on the snow absorbs heat. Similarly, as drought dust is released, snow melts at a higher rate, as has been seen in the Upper Colorado River Basin.

[…]

“When landscapes are charred during wildfires, they become more vulnerable to landslides and flooding. In January, a debris flow event in Montecito, California killed 21 people and injured more than 160. Just one month before the landslide, the soil on the town’s steep slopes were destabilized in [the Thomas Fire]. After a storm brought torrential downpours, a 5-meter high wave of mud, tree branches and boulders swept down the slopes and into people’s homes.”


More Information

Google Earth acquires imagery of Thomas Fire

Google Earth, the software that has aerial imagery from all over the world, now has satellite photos of the Thomas Fire. The photo above is from December 13, 2017. To see the fire images you will need to zoom in fairly close and select imagery from December, 2017 (View/Historical Imagery). The photos are from December 4 through 18, 2017.

The Thomas Fire burned 281,893 acres in December, 2017 near Ventura, California, making it for a surprisingly short time, the largest wildfire in recent California history. It destroyed 1,063 structures, damaged 280 more, and set in motion the factors that led to a series of flash-floods and landslides that killed 21 residents. Seven months later the Ranch Fire east of Ukiah became the largest in the recent history of the state, burning 410,000 acres.

Thanks and a tip of the hat go out to Robert.
Typos or errors, report them HERE.

Ranchers affected by Thomas Fire file lawsuit against California utility

Thomas Fire. Photo credit: Ventura County Fire Department.

Ranchers in Ventura County who lost cattle and property during the devastating Thomas Fire filed a lawsuit this week against Southern California Edison, claiming the utility’s outdated equipment and lagging fire mitigation efforts were to blame for what became the largest blaze in modern state history.

“The Thomas Fire was the inevitable byproduct of SCE’s willful and conscious disregard of public safety. SCE, although mandated to do so, failed to identify, inspect, manage and/or control vegetation growth near its power lines and/or other electrical equipment. This created a foreseeable danger of trees and/or other vegetation coming into contact with SCE’s power lines and/or other electrical equipment and causing electrical problems, including ignition of fires,” the complaints state.

The lawsuit, filed on behalf of two ranchers, is the latest in a series of suits lodged against the utility provider.

According to The Ventura County Star newspaper, a spokesman for Edison said the company would not comment until the official cause of the blaze has been released.

“The Thomas fire obviously has had an impact of many individuals, but the origin and cause of the fire continue to be under investigation and no report has yet been issued,” a spokesman said in a statement, as reported by the newspaper. “This and other lawsuits are not based on findings related to an investigation. Therefore, it would be premature for SCE to comment on the origin or cause of the recent wildfires.”

The Thomas Fire burned 281,893 acres, making it the largest wildfire in recent California history. It destroyed 1,063 structures, damaged 280 more, and set in motion the factors that led to a series of flash-floods and landslides that killed 21 residents. 

A report on the official cause may still be several weeks away.

Report released on Thomas Fire Fatality

Above: A map from the report showing the entrapment location. The red line was the firefighter’s path of travel. It leads from the black circle, which was the site of the first spot fires, to a drainage.

(Originally published at 6:25 p.m. MST January 8, 2018)

CAL FIRE has released a “Green Sheet” preliminary report for the line of duty death of CAL FIRE Fire Apparatus Engineer Cory Iverson of the CAL FIRE San Diego/San Diego County Fire Authority. Engineer Iverson was overrun by fire and killed December 14, 2017 while battling the Thomas Fire in Ventura County north of Fillmore, California.

While working with a hose lay along a dozer line he was attempting to suppress a  spot fire across the fireline. As one spot fire became multiple spot fires he attempted to escape but was not successful.

The entire 2.6MB report is here. The portion of the document that describes the entrapment is below. Fire Apparatus Engineer Iverson is “FAE1” in the report.


…FAE1 responded on the assigned tactical frequency, that he saw the spot fire. He engaged the spot fire that was on the edge of the dozer line with his hand tool.

Immediately after the report of the spot fire, a second spot fire was reported approximately 20 feet into the green.

At some point, before leaving the dozer line, FAE1 dropped a 100 foot length of hose from his hose pack on the dozer line. This action left 200 feet of hose still in his hose pack.

As FAE1 reached the second spot and began to take action, it erupted. At the same time, additional spot fires erupted along the dozer line west of the original spot fire. FF1 sprayed in the direction of the spot fires. The spot fires rapidly increased in size and the hose stream was ineffective. FAE1’s escape route back to dozer line was cut off. FAE1 began traveling southwest, paralleling the dozer line. Due to fire intensity, FAE1 turned and headed down slope to the south. FAE1 made a request, on the assigned tactical frequency, for immediate air support. This was the last confirmed radio transmission by FAE1. STL1 contacted HLCO for immediate air support. HLCO responded, he had additional copters coming in and they too would begin to work the area.

At approximately 9:25 AM, FC1 reported to FAE1 on the assigned tactical frequency, additional spots were below him and he told FAE1 to “Get out of there.”

The fire intensity increased in the green along the dozer line. FF1 and FF4 retreated along the dozer line, while FF2 and FF3 retreated along the dozer line and then up into the black, towards the mid-slope road. All four FF’s dropped their hose packs on the dozer line while retreating.

At approximately 9:27 AM, FC1 declared, on the assigned tactical frequency, “Mayday, we’ve got a firefighter down.” FC1 then clarified, “We have a firefighter trapped.” STL1 confirmed with DIVS X he copied the “Mayday” of a firefighter trapped. DIVS X acknowledged the traffic with STL1 and requested, through Thomas Communications, an ALS ambulance to the address of the staging area below the avocado orchard.

At 9:28 AM, the response from Ventura County Fire Station 27 was started.

Copter 1, and two CWN copters, continued working the area below the dozer line attempting to provide an escape route for FAE1. These copters saw FAE1 retreating down through the green.

At that time, two spots erupted down slope and south of FAE1, in his path, causing him to turn southwest and start down slope toward the eventual entrapment site.

FC1 saw FAE1 fall and lost sight of him. Copter 1 also saw FAE1 fall, but get back up and continue down slope toward the eventual entrapment site.

It was described by those who saw FAE1 moving through the vegetation that the height was chest to head high; and in some cases, all that could be seen was the top of his helmet.

Prior to the fire, the vegetation height and thickness masked the view of the deep gulch in the drainage, which was the location of the eventual entrapment site.

STL1 contacted HLCO, re-confirmed a firefighter was trapped, and was told by HLCO, six helicopters were enroute.

The additional CWN copters arrived and each copter began working the area where FAE1 was last seen. Those copters dropped retardant at first, and then switched to water due to a faster turnaround time.


Thanks and a tip of the hat go out to Tom.
Typos or errors, report them HERE.