With rainy season looming, residents of Lake Elsinore and other burn areas wait for the next disaster: mudslides

With the Holy fire drawing closer, Julie Hamilton was preparing to leave her house when an air tanker dumped pink retardant all over her white pickup. It was officially time to go.

For weeks in August and September, the fire prompted mandatory evacuations as it burned through canyons and mountainous terrain in Orange and Riverside counties, scorching 23,136 acres and at least a dozen structures.

Hamilton’s house near Leach Canyon in Lake Elsinore was spared from the flames. But now, like many others all over California who have endured the worst wildfire season in modern state history, she’s waiting for the next potential disaster: debris flows and mudslides.

In advance of a predicted storm that’s taken its time arriving, Riverside County officials issued a voluntary evacuation warning Tuesday afternoon for the Laguna, El Cariso, Amorose, Withrow A, Rice, AlberHill, Horsethief B, Glen Eden, Grace, Maitri and Glen Ivy areas of Temescal Valley and Lake Elsinore.

Crews in Hamilton’s neighborhood worked Wednesday afternoon to dig trenches and clear culverts in anticipation of the storm, ratcheting up work they’ve been doing in the area for weeks.

Hamilton is among many residents who remain hopeful that the Holy fire’s damage wasn’t severe enough to cause major instability to the hillsides near their homes that were once full of brush and trees.

“We’re hopeful we’ll get a nice light rain so everything will start to grow again,” she said. “I’m going to have faith that it will be OK.”

Rain clouds loomed over Lake Elsinore, the nearby Santa Ana Mountains and throughout the Southland all day Wednesday. At a parking lot at Storm Stadium baseball park, fire engines and California National Guard tactical trucks sat waiting to respond.

Officials have cautioned residents living in an 11-mile area between Ortega Highway, also known as State Route 74, and Horse Thief Canyon to remain alert.

That region hadn’t burned for more than 70 years. When the Holy fire came through, it left the soil waxy and primed for mudslides. In some areas, the fire burned almost two feet into the ground, killing off chaparral and other shrubs’ root systems that provide stability to hillsides.

Throughout the state, residents living near burned areas will have to remain alert throughout the rainy season. Emergency managers try to anticipate potential debris flows, based on weather reports and an area’s terrain, but they can’t be certain if or where a mudslide will happen.

“What we want residents to be concerned with is, when we issue some kind of warning, be cognizant of that,” said Jeff La Russo, a public information officer with the Riverside County All Hazards Incident Management Team.

“Know that we’re not here just trying to disrupt life. We’re here to make sure we’re protecting you and your property — and you cannot outrun debris flow.”

Once a mudslide begins, it’s almost impossible to avoid the avalanche of dirt and rock. Whether residents will respect the risk remains to be seen.

At the Temescal Valley Nail Salon, owner Holly Hoang stood outside Wednesday pointing to an area near her business that regularly floods. Next to her shop, a yellow sign warns drivers that the area is subject to flooding. She and her husband had discussed whether they should get sandbags to protect their two businesses.

Hoang said she was worried that because the scars of the Holy fire are less visible, and because no one died, people might not take the risk of flooding and mudslides seriously.

“A fire, humans can stop,” she said. “But the water, no one can stop.”

Near Horsethief Canyon Creek, northwest of Lake Elsinore, residents have already been busy clearing drainage ditches and laying out sandbags.

Peter Rasinski, a Horsethief Canyon resident and owner of So Cal Sandbags, said he and his neighbors have worked together to ensure they’re as safe as they can be when the storms come. Any runoff will drain into the Horse Thief Wash, which runs next to the neighborhood.

Rasinski wasn’t upset that the Holy fire burned a substantial amount of the 80 acres he owns in the Temescal Valley. It needed to burn. Brown and dry, the area used to be full of citrus trees, he said.

“The problem is, the fire was nothing — the flood is going to be way worse than the fire 10 times over,” he said. “It’s going to happen sooner or later. If not this time, next time.”

jaclyn.cosgrove@latimes.com

Twitter: @jaclyncosgrove