Fire-Damaged Areas Now in the Path of Flooding : Erosion: Efforts are under way to reseed charred hillsides and expand debris basins. Officials say a downpour could endanger 140 homes.

Government agencies are racing to reseed, clear drainage basins and erect barriers to protect homes before the first major downpour threatens floods and mudslides along San Gabriel Valley mountainsides denuded by fire last month.

County public works officials say about 140 foothill homes between Altadena and Sierra Madre are threatened by a wall of mud, rock and debris if a prolonged rainstorm pounds the charred slopes.

Fire and public works officials say that heavy showers this winter could wreak worse devastation than the Oct. 27 blaze. And meteorologists warn that the El Nino weather phenomenon appears to be returning for the second consecutive year. (Last winter’s drenching storms destroyed homes and buried highways in Los Angeles and Orange counties.)

“We could be in the same situation as with the fire,” said Capt. Michael Minore of the County Fire Department’s Station 66 in Eaton Canyon. “We’d be stretching our resources to deal with floods or slides here and in other hillside areas in the county that were burned (last month).”

“We’re talking about very steep terrain and (the burned area) is going to cause problems, whether it’s just flooding or mud coming down, if we have an intense storm for a prolonged period,” said Donna Guyovich, a public works spokeswoman, referring to the Altadena area.

“We’ve told people that, in the worst-case scenario, we’ll just ask them to evacuate,” she said. “If people have valuables they don’t want damaged, they should move them elsewhere now.”

County engineers estimate that about 1,300,000 cubic yards of earth and debris from the charred mountainside will come down this winter if the Altadena area is hit with heavy rain. Debris basins and other barriers along the base of the mountain can contain all but an estimated 200,000 cubic yards of debris. Still, even that amount can do enormous damage.

Moving like the inexorable flow of lava, the mud--laced with boulders, trees and brush--can invade houses and garages and inundate yards, swimming pools and automobiles.

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In an effort to capture that soil and debris, federal officials plan to spend more than $1 million to enlarge existing debris basins and erect new barriers. The county, the city of Sierra Madre and the U.S. Forest Service will also help pay for additional facilities to control erosion on their lands.

Federal and local authorities have tried to stabilize the scorched hillsides by scattering more than 20,000 pounds of quick-germinating ground cover seed on about 65% of the slopes by helicopter. Weather permitting, another seed drop of that size was scheduled for this weekend.

Looming in stark contrast to the increasingly green slopes beside it, the vast swath of brown, barren mountainside left in the wake of the blaze is an awesome reminder for hundreds of foothill residents that the fire’s devastation may have only just begun. Many longtime residents say the potential for floods and mudslides has never been greater, given the size of the burned area.

“We’re just praying the rains are not as heavy as last year,” said Altadena resident and Town Council member James Iamurri.

Residents and volunteers organized by charitable organizations and homeowner groups have placed tens of thousands of sandbags around threatened homes along the foothills. The county has already sent out about 110,000 sandbags to fire stations in the foothill areas around Altadena.

However, authorities say the bags are useful only to divert water that may inundate homes, or to build up the sides of stream beds or drainage structures. The bags will not stop a torrent of water, mud and debris in the case of a heavy downpour.

“If there’s a large hillside and it decides to come down in the rain, there’s no amount of sandbags or cement walls that will keep that hill intact,” said Minore of Station 66 in Eaton Canyon, where thousands of sandbags have been handed out over the past week.

“Our real problem is debris and mud flows to the extent it could block culverts and roads,” said Karl Dietzel, a Kinneloa Mesa resident and a member of the ad-hoc Eaton Canyon Fire Erosion Committee set up by homeowner groups.

“There’s a possibility that residents here could be isolated for periods.”

Dietzel has two packed suitcases in his car.

In past years of heavy rains, mudslides and floods have swept through homes, picked up cars and jammed them into swimming pools, and carried car-size boulders off the slopes and into neighborhoods.

In 1968, wildfire destroyed two homes in Pasadena Glen. The next year a torrent of boulders, mud and water washed through the area during heavy rains, crashing into some houses and floating cars away.

In the winter of 1978, a family in a mountain area of La Crescenta was trapped in their house as mud and rocks oozed through doors and windows.

That calamity was described by New Yorker magazine writer John McPhee in his 1989 book “The Control of Nature.” Guyovich recommends the book to residents who want to know more about debris flows and other hazards of living in the shadow of the San Gabriels.