Four years before the Palisades and Eaton fires ravaged L.A., Irvine braced for a blaze of its own.
A bone-dry summer left the landscape parched and primed to ignite as Santa Ana winds roared through the region at 80 mph. On the morning of Oct. 26, 2020, the Silverado fire erupted.
Firefighters deployed. The city initiated its emergency plan. Residents of Orchard Hills — a master-planned community straddling the wildland-urban interface and sitting in the path of the quickly growing fire — fled, not knowing whether they’d ever see their homes again.
Orange County Fire Authority firefighters work to protect homes in the Orchard Hills neighborhood of Irvine during the Silverado fire in October 2020.
All of them would. The flames licked at the neighborhood’s outskirts, toasting a few leaves at the perimeter, but didn’t damage a single residence in the community.
The firefight was an unequivocal victory — a product of the meticulous planning of the neighborhood, the design of its homes and the painstaking plan set in place by the city.
As L.A. looks to fortify itself against future fires, Orchard Hills could serve as the road map to get there.
Of course, the comparison isn’t exact. Irvine is a newer city with modern homes built using lessons learned from dozens of deadly fires over the years. Altadena and Pacific Palisades are communities with tree canopies and century-old houses navigated by narrow, sometimes winding roads chock-full of vegetation.
But as climate change sees Southern California burn time and time again, experts say that success stories should be extracted and mined for all they’re worth.
You could argue that Orchard Hills’ fire resistance began a century ago, when Irvine Valencia Growers planted an avocado orchard in the hills above the community. The orchard grew into one of the nation’s largest avocado producers in the decades since, with roughly 100,000 trees across 800 acres.
It offers the neighborhood a lot more than guacamole.
“The orchards have a built-in irrigation system, so when a fire starts, the landscape is already watered,” said Sean Doran, a fire captain with the Orange County Fire Authority.
Doran, who fought the Silverado fire, said his team had a leg up thanks to a decade-long partnership between Orchard Hills and the fire authority stretching back to when the developer, Irvine Co., broke ground in 2014.
In Irvine, building plans must go through the fire authority as a condition of a developer’s conditional use permit.
“It’s inherent in the process,” Doran said. “If you’re a developer, at some point you’re going to be walking through our door.”
The partnership between the developer and the fire authority brings strict rules for what can and can’t be built, and many homebuyers are grateful for the regulations.
Ron Nestor, an Orchard Hills resident and senior principal at William Hezmalhalch Architects, noticed a small coil of smoke while walking his dog on the morning of the Silverado fire. An hour later, he evacuated his home.
Ron Nestor and his dog, Enzo, enjoy his backyard in Orchard Hills in Irvine this month.
He was gone for three days. When he returned, there was no damage whatsoever.
“It’s a testament to the way this place was planned,” he said.
When Nestor moved into Orchard Hills five months before, the neighborhood’s fire plan, which Irvine Co. touts on its website, was a factor for moving in. The parameters were created by the developer, the fire authority and a third-party fire behavior analyst who examined wind patterns, topography and fire history.
Orchard Hills is designed with numerous levels of defense for an oncoming fire: in the open land surrounding the neighborhood, in the yards and in the homes themselves.
It starts with the fuel modification zone — open space around the community that can be modified to reduce fire risk by replacing combustible vegetation with fire-resistant shrubs. Orchard Hills’ zone is filled with prickly pear cacti, Japanese honeysuckle and Formosa firethorn.
Orange County’s fire guidelines call for three different tiers of fuel modification zones, with different construction requirements and shrub removal rates typically extending up to 200 feet outside the perimeter. If a developer wants to tighten that zone down to 100 feet, they have to make up for it in other ways, such as building an exterior wall around the neighborhood, or adding extra fortification on homes at the edge of the neighborhood, so they don’t ignite and bring the fire inward.
Open space around Orchard Hills is filled with prickly pear cacti, Japanese honeysuckle and Formosa firethorn.
“Not everything is concrete, so we can give some leeway in one area and tighten up another,” Doran said. “We’re here to support a fire-hardened community. Whatever makes that happen is a success for both parties.”
In the case of Orchard Hills, the fire authority worked with farmers to tweak the spacing of avocado trees to have fewer trees per acre and cleared the brush and sage in the orchards to limit flammable objects in the 170-foot fuel modification zone.
The next level of defense comes where the open space meets the outer rim of homes.
Irvine Co. erected a 6-foot wall around an enclave on the north part of the neighborhood — where a Santa Ana wind-driven fire would most likely hit first — to protect the most vulnerable properties from radiant heat and keep low-flying embers out of the development.
It beefed up the homes along that rim beyond the fire-hardening standards required in the rest of the neighborhood. These sections call for fire-rated exterior doors and stringent guidelines on outdoor features such as decks and trellises.
The last line of defense comes inside the neighborhood.
You won’t find wood-shingled Craftsmans in Orchard Hills. In fact, there’s not much exposed wood at all, and if there is, it’s treated to be fire-retardant. Masonry walls and vinyl fences separate properties, and the few wooden gates are isolated by metal posts so they can’t spread fire to the house, Nestor said.
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1. A view of asphalt shingle vents that are placed on roof tiles on homes. 2. Masonry walls and vinyl fences separate properties, and the few wooden gates are isolated by metal posts so they can’t spread fire to the house. 3. Ron Nestor’s home, which was built to be fire-resistant.
Orchard Hills homes are constructed with two factors in mind: radiant heat and ember intrusion. Radiant heat is the heat projected by fire; if a home’s exterior is made of flammable materials, the house can heat up to the point of igniting. So houses are mostly Mediterranean, wrapped with stucco or fiber cement — noncombustible materials — with a few splashes of stone and brick thrown in.
The other factor, ember intrusion, is when embers enter a home through an opening and ignite it from within. Orchard Hills homes are outfitted with tempered glass, which is stronger than single-pane windows that tend to break in fires. Roof vents have mesh filters that block embers. And roofs are laid with either concrete or clay tile. The concrete tile lies flat, stopping embers from entering. With the barrel clay tiles, the opening on the bottom of each row is plugged with a bird stop, which keeps out birds — and embers.
The HOA guidelines are rigorous and firm, dictating acceptable plant types and where trees are allowed to be planted. Nestor said he appreciates the precautionary measures.
“People are confident that their homes will survive because when the neighborhood was put to the test, it held up,” Nestor said. “Everything went exactly according to plan.”
Doran said the fuel modification zone, combined with the wall, helped stop the Silverado fire in its tracks.
“I watched the fire burn up to the edge of the wall and then die down,” he said.
Fire after fire has shown that one of the most crucial aspects of the emergency are the roads. In the Camp fire in 2018, eight of the 84 people who died were stuck in a traffic jam when the flames roared over them.
Most of Irvine is navigated by smooth, wide roads, making it much easier for people to evacuate and firetrucks to get to the fire. In Orchard Hills, 7-foot-wide paths run behind the properties, so fire crews and vehicles can better access the back sides of homes.
Bobby Simmons, Irvine’s emergency services manager, helps coordinate the city’s strategy.
In 2019, in the wake of the Camp and Woolsey fires and a year before the Silverado fire, Simmons helped form a 25-person initiative to create an all-inclusive wildfire plan so if one ever broke out in Irvine, every city department would know its role exactly.
Firefighters defend homes in Orchard Hills in 2020. The Silverado fire licked at the Irvine neighborhood’s outskirts but didn’t damage any houses in the community.
The police department dispatches patrols to specific intersections to aid evacuations. The traffic management center remotely controls signals, avoiding traffic jams by turning all the lights green for street lanes going away from the fire. Simmons said the Office of Emergency Management mobilizes an emergency operations center and activates an emergency landing page on its website leading to a real-time evacuation map — with bandwidth for more than 3 million visitors over three days without crashing.
“We developed the plan, challenged it and tested it so much that when rubber met the road on Oct. 26, we provided a structured process for a chaotic event,” Simmons said. “All things considered, it went smoothly.”
During the Silverado fire, the city evacuated 90,000 people in four hours from northern Irvine communities such as Orchard Hills and Portola Springs.
The Silverado fire turns the sky orange as it burns close to a home in Orchard Hills in 2020.
Ultimately, the Silverado fire still took a toll. Although there was no damage in Orchard Hills, five structures were destroyed elsewhere, 11 were damaged, and two firefighters were critically injured. And although traffic quickly flowed out of the neighborhoods, cars were backed up for more than a mile because the lights getting onto the 5 Freeway were controlled by Caltrans, not Irvine, and couldn’t be programmed to accept the droves of cars coming from the northeast.
There’s always more to learn.
“Now, we identify the lessons we learned to get ready for the next one,” Simmons said.
