CALIFORNIA : Hillside residents fear more mudslides : Six foothill homes in La Canada Flintridge are damaged after a surprise downpour triggers a debris flow.

On his drive home from a football game Thursday night, Phil Markgraf noticed light rain falling on his windshield.

Although torrential mudslides are feared by residents of La Canada Flintridge and other communities below hillsides charred by the Station fire, Markgraf didn’t think the drizzle was enough to trigger a debris flow.

Once he arrived home, however, the sprinkles turned into a downpour that “thundered” on his roof, Markgraf said.

Then the phone rang. It was his neighbor Steve Brown, and he needed help.

Earth was flowing toward his home despite the tiered wooden walls he had built on the hill just above his residence, and the sandbags and railroad ties he had stacked on his back patio.

Markgraf, 43, a software engineer, put on boots and rain gear and grabbed a shovel.

“Once the rain started, it immediately started flowing mud down, so they had to rush,” Markgraf said.

In the end, Brown’s home was safe -- thanks largely to the precautions he took -- but debris flows caused minor damage to six other homes in La Canada Flintridge.

Brown, 52, said it was good that the rain dislodged some of the debris without “burying my house.”

Thursday night’s rain was unexpected. Forecasts had called for light rain, but as a weak cold front moved through the area, a storm cell formed. Showers began to fall at 10 p.m. and as the storm neared hillsides, the rains increased in intensity, causing a third of an inch to fall in a 20-minute span, said Eric Boldt, a meteorologist at the National Weather Service’s Oxnard office.

No mandatory evacuations were ordered, said Inspector Matt Levesque of the Los Angeles County Fire Department, though six homes were self-evacuated. In the end, the incident proved that it doesn’t take much rain to trigger a mudslide.

“This was a small storm,” said Arthur Vander Vis, an on-site engineer for the county Public Works Department. “It’s a wake-up call for the residents. We’re not joking when we put all these K-rails out here. It’s serious.”

Officials have said the concrete barriers will stay in place for three to four years because the hillsides are completely barren in the wake of the Station fire, which charred more than 160,000 acres. It was the worst wildfire in L.A. County’s history.

Many measures had been put in place, including the clearing of debris basins, the notification of residents in high-risk areas, the distribution of sandbags and the laying of several thousand feet of K-rails.

On Thursday, the nearby debris basins and inlets captured much of the mud, officials said. “The system stood up. It worked,” Vander Vis said.

In the next few days, the Public Works Department will clean out those inlets. In the next two weeks, crews also will clean out the Mullally Debris Basin, which can hold 9,400 cubic yards of material but was filled within roughly 30 minutes Thursday night.

The speed of the cleanup is important as more rain could arrive in the area by the middle of next week, Boldt said. There also is the issue of El Nino rains, which National Weather Service spokesman Bill Hoffer said are expected by the end of this year or early 2010.

Among those who voluntarily evacuated Thursday night were Gary and Diane Stibal, who had spent $35,000 on precautionary measures to protect against mudslides. That included installing a chain-link fence, erecting walls of sandbags and building a large concrete gutter into a hillside that sits against their backyard.

When the rains came Thursday, they seemed prepared.

“We thought it was going to be sprinkles and my husband loves the sound of rain,” Diane Stibal said. “He said, ‘Oh, I love that sound’ and I said, ‘Gary, I hate that sound because we don’t know what’s going to happen.’ ”

She said the rain was so loud that her husband ran to close their new storm windows. But the mud was already flowing, so they left. By about 11 p.m., they called 911 and waited on fire trucks before following them back up Ocean View Boulevard.

At their home, much of the fence was bent, the sandbags were buried and the backyard sat beneath a thick layer of black mud. A few ferns poked through, and Diane Stibal’s lemon boy tomato plants along the edge were spared.

“This was a beautiful lawn,” she said. “This was $32,000 worth of landscaping. I had just planted my pansies.”

Although their house sustained minor damage, Diane Stibal said she wasn’t upset about not being warned earlier by city officials. “It happened so fast,” she said. “They would have had to have been God to know this was going to happen because it was 15, 20 minutes, then boom.”

An evacuation plan for mudslides in the foothill communities is “very close” to being finalized, said Bob Spencer, chief of public affairs for the Public Works Department.

Pat Anderson, who lives at the top of Ocean View Boulevard, said Thursday night was deja vu after her home was damaged by 1974 mudslides that destroyed the front lawn. She has three K-rails in front and can put a temporary one across the driveway if need be, but her home was safe.

For Brown, who began building barricades shortly after the Station fire was declared contained, the task now is repairing the damage and fortifying the defenses.

“They were saying we’re in for El Nino, so we’re going to dig it out today [and add] more sandbags because we realized we could have used some more,” Brown said. “I haven’t figured out where I’m going to put the mud yet. I think I’m just going to put it out on the street.”

--

baxter.holmes@latimes.com