Posts Tagged: defensible space
The unspeakable loss of human life and the serious challenges being faced by survivors has dominated the Camp Fire conversation. Now, UC Cooperative Extension is beginning a dialog with many agencies involved to understand how such tragedies can be prevented in the future.
UC Cooperative Extension fire scientists and representatives of many California organizations conduct fire behavior research, study forest treatments – such as prescribed burns, timber harvest and mastication – and share best practices for home and community preparation. In the Butte County area where the Camp Fire took place, cooperating agencies include CalFIRE, the U.S. Forest Service, the Butte County Fire Safe Council, the Yankee Hill Fire Safe Council, Sacramento River Watershed Program, the Sierra Nevada Conservancy, the Bureau of Land Management, and others.
While the Camp Fire was devastating, it could have been far worse. Working together for decades, the partner agencies have improved community safety and resilience.
They have educated the public about defensible space, fire resistant homes, and evacuation plans. They have coordinated fuels treatments along evacuation routes and around the communities. Through their actions, they saved many lives and structures, protected the town's drinking water supply, and in some cases, provided access for hiking in areas that had been overgrown by brush.
“When you drive for miles through blackened, burned trees and then arrive in a thinning project area full of green tree tops, you know that these efforts are worth it, we are having success and we can make a difference together,” said Calli-Jane DeAnda, executive director of the Butte County Fire Safe Council.
Because of the Camp Fire tragedy, the partner agencies learned many lessons that can inform future maintenance and treatments to improve fire resilience in Butte County and other wildland areas. Kate Wilkin, the UC Cooperative Extension fire advisor for Sutter, Yuba, Butte, and Nevada counties, is able to point to projects implemented in the Camp Fire zone that saved lives and structures.
For example, one family in Paradise was featured by the news media for their successful advance fire planning, which even included the installation of sprinklers on top of the house.
“When I think about what saves a house, a sprinkler is a cherry on top of the cake,” Wilkin said. “If a house is constructed with a combustible roof and siding, if unprotected vents allow embers to get into the attic, or the landscape is not maintained, a sprinkler isn't going to save the house. The sprinkler's power from the grid or a generator will likely fail. High winds may even prevent the sprinkler's mist from hitting the house.”
Rather, passive resistance to fires through better building design, materials and maintenance greatly reduce structure loss.
“Maintenance is an unsung hero of fire resilience,” Wilkin said. “Individual actions at our homes matter.”
First 5 feet around a structure
State law requires homeowners in wildfire areas to clear 100 feet of defensible space around their structures. Most towns in wildfire-prone areas also have their own defensible space codes. Wilkin said where she lives in Grass Valley, anyone with less than an acre of land must maintain their entire property as defensible space.
This guideline is a start, but there is more that people who live in wildfire-prone areas can do to make their homes resilient to fire. UC Cooperative Extension scientists recommend creating a five-foot buffer immediately surrounding the home almost completely devoid of plants and anything that can burn - including wooden fences, firewood, deck chairs and pillows, brooms and other wooden tools.
This extra precaution is important as embers from a distant wildfire can land on or adjacent to a house and ignite combustible items which in turn ignite the home. It was evident in the Camp Fire that the first five feet around homes was a critical factor in the survivability of structures.
The zone can include noncombustible materials such as rock mulch, stone pavers, cement, bare earth, gravel or sand. Low combustibility materials, such as irrigated and maintained lawn or herbaceous plants less than five inches high, are okay. All leaves, needles or other vegetation that falls in this five-foot zone must be removed during the fire season.
“The non-combustible space adjoining the house may be the difference between losing it and all the contents to a wildfire versus returning to the property with the home unscathed,” Wilkin said.
Community fire resilience
Fire survival measures can also be taken at the community level.
In Paradise, the Butte County Fire Safe Council funded CalFIRE crews to thin a number of areas in the watershed below Paradise Lake in 2013 and 2014. Taking these actions allowed an area for firefighters to start a defense and start putting out the flame front, Wilkin said.
“A CalFIRE chief told residents, ‘You provide the offense, we provide the defense.' Homeowners and communities need to get everything set up for successful firefighting,” she said.
Forest thinning has the added benefit of improving recreational opportunities. Near Magalia Pine Ridge School, an 11-acre mastication project in 2018 funded with $30,000 from the Butte County Fire Safe Council cleared overgrown vegetation around the school. This helped strengthen the area's public assembly location, which was identified on the community's evacuation map, and opened up access to a forest hiking trail that was blocked by tangled brush.
The open space dramatically slowed the raging Camp Fire when it approached the school, which is now one of the only schools open in the Paradise Ridge community.
Forest thinning also protected the drinking water for the town of Paradise. A combination of projects undertaken by U.S. Forest Service, Sierra Pacific Industries and the Butte County Fire Safe Council aligned to allow fire fighters to combat the fire and ensure that the source of drinking water was protected.
Concow wildfire safety zone
In 2013 and 2014, the Butte County Fire Safe Council and Yankee Hill Fire Safe Council created a wildfire public assembly safety zone in Concow. The work was completed by inmate crews. During the Camp Fire, dozens of lives were saved when sheriff deputies, firefighters and citizens were able to shelter in the area.
“Wildfire safety zones are pretty uncommon and we may want to create more in wildfire prone areas,” Wilkin said. “But there is a hitch.”
CalFIRE is reluctant to designate temporary refuges because they don't want people to rely on them in place of evacuation. During a quick-moving firestorm, it could be an area where people can shelter if they cannot get out.
“It's a complex and dangerous puzzle,” Wilkin said. “In Australia, they had a similar idea and some places where people sheltered in a fire caused them to die.”
Wilkin is working with Paradise parks to identify areas ahead of time with enough space to meet new national firefighter standards to protect people's lungs from superheated air.
“Historically, we thought sufficient space was four times as great as the flame heights. If you have a Ponderosa pine that's torching 150 feet high, you would need 800 feet around the people,” Wilkin said. “New research has found that the safety zone calculation must also consider potential wind speed and slope. Significantly more space may be needed.”
Shades of brown and grey cast over bricks, cement, remnants of metal roofs and steel beams from manufactured and modular homes, collapsed stucco walls, BBQs, shells of washers and driers, along with an occasional tea pot—that is what you can see in and amongst living, but singed Ponderosa pine and California black oak trees where the Camp Fire burned. How did California's most deadly fire happen and what might be done differently to ensure a better outcome? These are difficult questions that California will wrestle with for a long time to come.
Last week I was able to tour some of the burned area in Paradise and Magalia to evaluate why some homes survived and others did not. This gave me a chance to look at homes that survived largely on their material selection, design details, the owner's maintenance efforts, and not necessarily with the aid of a fire crew or resident that stayed. Many of the buildings that were burned were lost on the first day or two of the fire while emergency response was focused on evacuating the communities. It will take months to make sense of this mess and tragedy, but during my tour some conditions rang true to me.
- Wildfire is not uniform. Not all fires are the same and not all houses experience the same type of fire. When you are looking at home losses and survivors, keep in mind that each home may not have had the same fire exposure. Some homes experienced significant ember exposure, while others ignited because their neighbor's home succumbed to fire and the heat of their neighbor's house caught their house on fire, while others were protected from the wind and its deadly embers. Paradise and Magalia have blocks and blocks of nothing but foundations, but amongst these bleak conditions are a few intact or partially damaged homes that have a story to tell.
- We saw homes that survived that had upgraded attic and foundation vents that meet the California building code for construction in wildfire prone areas. Some of these houses also included some extra efforts where vegetation and combustible mulch was virtually eliminated in the area immediately adjacent to the home. Our inspection team included UC's Dr. Steve Quarles, a national expert in fire-safe construction, who interpreted this to mean that meeting the 2008 Chapter 7 A standards, coupled with the enhanced defensible space, likely made the difference to ward off the assault of the ember-driven Camp Fire. We found evidence that burned homes in Paradise had ¼” mesh foundation and under-eave vent screens. Research has shown that these larger size screens let embers penetrate the attic and ignite the house from within. The 2008 California building code standards specify screen mesh size between 1/8” and 1/16”-inch, or vents that demonstrate their ability to resist embers and flames.
- Our tour also confirmed that landscaping plants and wood mulch placed right next to the house creates vulnerability. While looking at the rubble of a home, it can be difficult to tell what happened; however, we saw several surviving houses with broken glass or otherwise damaged dual-pane windows that experienced heat exposures sufficient to crack glass in the windows, but the home still survived during these first two days when fire crews were rightly focused on community evacuation and not structure protection. For the houses that did not survive, we can interpret that in addition to the vulnerabilities in vents or a roof, heat can easily break glass in windows, especially if those windows are single pane, and can likely created a pathway for fire to enter the houses.
Wood mulch and landscape plants burned adjacent to this newly constructed home. Several windows were broken from the heat from this fire. The home met the new construction standards and survived, but likely would not have been damaged if there had been a 5-foot zone around the home that did not contain combustible plants or other materials.
- Home placement makes a difference. A home at the top of a canyon or gulch can easily be overwhelmed by wildfire by taking on additional heat as the fire approaches and being blasted with embers. This is not a new concept, but the homes in the broader Paradise region were especially vulnerable when they were located above these gulches and canyons. Enhanced vegetation management is highly recommended that includes a 5-foot non-combustible zone immediately adjacent to the home.
Our team, which also included Dr. Eric Knapp from the USDA Forest Service Pacific Southwest Research Station, has been able to do a quick analysis of home losses by year of construction in Paradise. This cursory analysis shows that many homes built after the 2008 wildfire standards were adopted were lost during this fire, however, without knowing the specific details of each home (e.g., maintenance practices, proximity to other building, etc.), these statistics can be misleading. We will continue to work through the available data to try to look for patterns, however, in the meantime, it seems clear to me that the new construction standards can reduce the probability of ember intrusion and may have helped for some homes in Paradise. This week a new study reported that complying with these standards was not considerably more expensive. Additionally, the codes that help guide construction in California's wildfire-prone areas are dynamic and will be informed by the 2017 and 2018 wildfire seasons.
For me thinking about Paradise in the abstraction was easy. Visiting it was different. The name says it all. After my visit I could understand why someone would choose Paradise or Magalia; the views are awesome, the air is clear, the forest and woodlands are amazing. I can only imagine that the community was (almost) perfect. Rebuilding a more resilient community will take considerable thought, effort, and some radical new ideas.
Reposted from the UCANR News
Newly minted UC fire scientist Kate Wilkin moves into fire country
Fire scientist Kate Wilkin was on the job just a few weeks when ferocious winds whipped up the Northern California firestorm of 2017. The national media focused on Napa and Sonoma counties, where the deadly Tubbs fire became the most destructive wildfire in California history, while devastating fires also broke out in Butte, Nevada, Yuba and other counties.
It was crunch time for Wilkin, who stepped in as the new forestry, fire science and natural resources advisor for UC Cooperative Extension in Sutter, Yuba, Nevada and Butte counties that fall. Four lives and 200 homes were lost in her new work community. Wilkin will now host workshops to help families and businesses recover from the firestorm and rebuild in a way that is more resilient to fire. Fire resiliency will start at her own home.
From the Bay Area to the small town of Grass Valley
Wilkin and her husband Josiah Johnston moved into their first home, a ranch-style rambler atop a hill in Grass Valley, on Sept. 15, three days before Wilkin reported to work in the Sutter-Yuba County UC Cooperative Extension office in Yuba City.
The couple moved from a small apartment in Berkeley, where Wilkin was conducting research as a post-doc in the lab of UC Agriculture and Natural Resources researcher and UC Berkeley fire science professor Scott Stephens. The move from a hyper-urban Bay Area city to a small hamlet in the hills wasn't too much of shock to their systems. Johnston was raised on a farm with chickens and goats. Wilkin grew up in the rural Appalachia community of Abingdon, Va. After completing her bachelor's degree at the College of William and Mary, an internship with the Nature Conservancy in Kissimmee, Fla., introduced Wilkin to fire science.
“In the Disney Wilderness Preserve, the landscape would burn then flood every year,” Wilkin said. “I became fascinated with how these disturbances catalyzed diversity.”
What better place to continue a fire education than California?
Wilkin enrolled at CalPoly, San Luis Obispo, earning a master's degree in biology. She spent the next three years in Yosemite National Park, working with a team of scientists to understand the impacts of packhorse grazing in mountain meadows.
“We found that the current policies led to meadow degradation,” Wilkin said. Yosemite then changed its policy to reduce the amount of horse grazing on these tender, sensitive mountain resources.
In 2011, Wilkin started work on her doctorate at UC Berkeley, where she studied the relationship between fire, forest diversity and water. Wilkin signed up for the pilot Graduate Students in Extension program at Berkeley, launched in 2014 to train and recruit graduate students for careers in research and outreach.
“The … internship gave me an amazing set of professional skills that I could practice, including media relations, public speaking to different audiences, and conference organizing and facilitating,” Wilkin told Science Magazine for an article about the innovative program. “Many of my colleagues and I see environmental problems and want to do applied research because we want to help find solutions.”
Beginning at home
With full knowledge of the dangers of living in fire-prone areas, Wilkin and Johnston purchased a home close to the outdoor amenities they adore – hiking, backpacking and skiing.
“Tahoe is just an hour away,” Wilkin said. “I love the view from the house and the wooded setting. But we live in an area CalFire has designated as very high fire danger.”
As a fire scientist, Wilkin was well equipped to make changes to the home and landscape to minimize the risk.
“We moved in during peak fire season,” Wilkin said. “We didn't hang artwork. My priority was to make the home and deck more fire resistant. We put in one-eighth-inch mesh over the vents, caulked around doors and windows, blew leaves off the roof and deck, removed lattice wrapping the deck and cleaned the gutters. Then we created defensible space starting close to the house and working our way outward."
The couple labored about 200 hours and spent about $800 in the first six weeks buying and renting tools, including a chipper, saw and a truck to haul away tinder-dry lattice, foliage and pine needles. With the most critical fireproofing completed, the couple is now tallying the work that should be done to further enhance the fire safety of their home.
“We probably need another $6,000 to $7,000 of work,” Wilkin said.
When the North Winds blow
Wilkin recalled the terrifying time about a month after moving into their new home when howling winds whipped around the house and fires were breaking out across Northern California.
“The North Winds are haunting,” she said. “I hadn't felt wind like that since I lived in Florida and experienced hurricanes.”
Wilkin and Johnston were fortunate. The closest fire to their home was the McCourtney Fire, which burned 76 acres in Grass Valley. The wildfire stayed two miles away.
California law requires homeowners in wildfire-prone areas to create 100 feet of defensible space around their dwellings. UC Agriculture and Natural Resources (UCANR) experts suggest going a bit farther by creating a five-foot buffer immediately surrounding the home completely devoid of plants and anything that can burn.
Few people think about creating the non-combustible zone, said UC ANR Cooperative Extension advisor Yana Valachovic, because they are so accustomed to foundation plantings. “Plants are used to anchor the house visually on the landscape. Without them, a house can look naked,” Valachovic said.
But the non-combustible space adjoining the house may be the difference between losing it and all the contents to a wildfire versus returning to the property with the home unscathed. This extra precaution can be important, Valachovic explains, because, “embers from a distant wildfire can land on or adjacent to your house and ignite combustible items.”
In the five-foot non-combustible zone, even such common items as firewood, deck furniture, a wooden ladder, , brooms and other wooden tools should be absent during the fire season.
Rock mulch, decorative stone “hardscape,” and concrete paths can be aesthetically pleasing alternatives.
“We have to simplify our landscapes and accept less vegetation to improve fire safety,” Valachovic said.
UC Agriculture and Natural Resources is involved in fire research and education statewide, helping enhance understanding of fire's role in human communities and natural areas. A range of UC ANR publications and online tools address wildfire risk, fuels impacts of forest diseases and home wildfire mitigation. UC ANR is part of the California Fire Science Consortium, a network of fire science researchers, managers, and outreach specialists tasked with improving the availability and understanding of fire science and management knowledge.
Valachovic, the UC ANR forestry advisor in Humboldt and Del Norte counties, recently hosted a webinar (recording available online) for homeowners in areas at wildfire risk, during which she said a five-foot non-combustible zone around the home increases the likelihood of home fire survival and provides several additional benefits to rural homeowners.
“If you have five feet of non-combustible area immediately next to the house, you don't have to cut back plants for siding maintenance and there's ample space for placement of a ladder to clean the gutters,” she said. “The open space also provides access for cleaning up any accumulation of pine needles and leaf litter, also a significant fire risk.”
Ten years ago, California extended the defensible space rule from 30 feet to 100. The area within 30 feet of the home should be maintained in a way authorities call “lean, green and clean.” Dry grass, leaves, brush and dead wood should be cleared. Open areas should be left between islands of vegetation in the 30-foot-zone to disrupt the path of a fire to the home. Trees within six feet of the house should be cut back or removed entirely.
Beyond 30 feet, in the extended 100-foot reduced fuel zone, fire officials ask that landowners remove dead wood, debris and low tree branches. Small trees and plants growing under trees should be removed, as they act as ladders giving ground fires access to tree crowns.
Valachovic said “fire resistant” plants can be characterized as having low growth, open structures, not holding on to dead leaves and having leaves with high moisture content. But she said no vegetation is truly fire safe.
“Landscape maintenance is essential,” Valachovic said. “All plants can burn under the right conditions.”
An initiative to maintain and enhance healthy families and communities is part of the UC Division of Agriculture and Natural Resources Strategic Vision 2025.
Wildfire Summit pulls together Tahoe basin residents and agencies on the fourth anniversary of the 2007 Angora fire to improve implementation of defensible space
The Lake Tahoe Wildfire Summit was held in Tahoe City on June 24th, 2011, four years after the Angora fire which started on June 24th, 2007 in South Lake Tahoe. The summit drew together over 100 basin residents, agency staff and policy makers to focus on ways to reduce wildfire risks to Tahoe homes and communities. Presentations centered on wildfire issues in the Tahoe Basin and how to reduce risk to homes and communities by creating defensible space, improving building materials and design, and implementing forest fuels reduction projects. Participants also went on field trips to the nearby Washoe fire, to a forest fuels reduction project implemented at Granlibakken resort (the hosting venue), and to a nearby neighborhood to examine the flammability of home construction.
After reaching a highpoint in 2007 due to the Angora fire, the level of concern about wildfire and motivation to do defensible space seems to be tapering off at the lake according to many fire agency staff. Participants cited residents’ and homeowners’ attitudes as the foremost barrier, saying that people don’t care about fire hazards, don’t think of natural vegetation as needing maintenance, or would rather recreate than do yard work. This attitude may be deeply ingrained at Lake Tahoe, a community where leisure and recreation in the “natural” outdoor environment is deeply valued.
Lack of understanding about the issue and denial that a wildfire could happen again were also cited with some reporting time they had been told by locals that Tahoe had an “asbestos” forest and wouldn’t burn. Other concerns are that vegetation removal for defensible space will look unsightly or reduce privacy. Also, there is a perception that defensible space actions are illegal or clash with water quality best management practice requirements required by local and regional government to preserve Lake Tahoe’s famed clarity.
Ownership patterns, including second home ownership and a high percentage of rental properties, reduce the opportunity and ability for some to complete defensible space. Costs are a factor for some residents, especially during the current recession (though there are currently rebate programs in place that can pay up to half of the cost of defensible space treatments). Disposing of materials can also be difficult.
Attendees at the Summit brainstormed and prioritized strategies to overcome these barriers to defensible space implementation. Education was cites as the major need to increase implementation. Education should focus on increasing awareness and understanding of the fire issue at Tahoe and highlighting the attractiveness of defensible landscapes. A major goal should be to develop a culture that doing defensible space is just a part of living at Lake Tahoe. Helping residents understand that defensible space is not only legal, it’s required and will eventually be enforced was also key. Following up with actual enforcement actions was identified as critical to this effort.
At the end of the day, all participants said the summit helped to clarify wildfire issues in the Tahoe Basin. 88% said it will help their communities work together to reduce wildfire risk and that they personally had a better idea of how to reduce wildfire hazards in their community.
Partner agencies included the seven local fire agencies in the basin, CalFire, the Nevada Division of Forestry (NDF), the Tahoe Regional Planning Agency (TRPA), the US Forest Service and both the University of California and University of Nevada Cooperative Extension. Funding for the event was provided by the NDF, TRPA, fire resistant construction material manufactures, and local defensible space contractors.
For a full account of the event, please download the Summit Report
For more information on how to implement defensible space at Lake Tahoe, go to: www.livingwithfire.info/tahoe