Crews Hustle to Clear Flood Channels : Weather: Engineers labor around the clock to clean up debris from last storm as forecasters predict more rain today and next week.

Emergency crews continued mopping up from the last storm Friday and made hasty preparations for the next one, as forecasters predicted more heavy rain this morning in the still-sodden Southland.

The National Weather Service said the wet, blustery weather system expected to arrive before dawn today probably will not match the one that overburdened Southern California’s complex urban flood-control system Wednesday night, although it will pack a punch.

“We could have some more flooding, although probably not as severe as Wednesday’s,” said Curtis Brack, a meteorologist with WeatherData Inc., which provides forecasts for The Times. “Maybe some mudslides too.”

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With that in mind, and the prospect of another storm early next week, flood-control engineers were working overtime Friday, clearing channels of the mud, brush and debris that piled up this week, deploying heavy equipment to threatened areas and making sure that pumping stations were functioning properly.

“As we learned a couple of days ago, we never know where the heaviest rain will fall, so we want to be prepared for anything,” said Jean Granucci, a spokeswoman for the Los Angeles County Department of Public Works.

She said Wednesday’s storm--which dumped up to 5 inches of rain in some areas within a few hours--was too much to handle, even for the network of 15 dams, 129 debris basins, 470 miles of open channel and 2,300 miles of underground storm drains that make up what she calls “one of the most sophisticated flood-control systems in the world.”

“It was just a matter of too much water too fast,” Granucci said. “You can’t design a system that will handle that intense a rainfall in that short a period of time, especially where you don’t expect it.”

Rainfall usually is heaviest in the mountains and foothills of Southern California, but Wednesday the low-lying areas--such as Carson, El Segundo, Long Beach, San Pedro and Torrance--took the brunt of the storm.

The runoff flooded scores of homes and businesses, inundated vehicles and claimed the life of a man who apparently succumbed to carbon monoxide poisoning while his car was stranded in a flooded Long Beach intersection.

Granucci said the downpours knocked out electrical power to some key pumping stations used to lift floodwaters in the low-lying areas into adjacent storm-drain channels, and that compounded the flooding problem.

By Friday evening, the pumping stations were all back on line, and the debris basins, flood channels and storm drains were largely cleared, Granucci said. “We’re monitoring the weather and the crews are on standby.”

One of the places hardest hit by Wednesday’s flooding was the Food Bank of Southern California in Long Beach, where more than a million pounds of food for the needy was destroyed by the rising water.

“This is just devastating to us,” said Jane Roosevelt, whose husband, Delano Roosevelt, chairs the food bank board. “For the most part, anything sitting on the floor was lost.”

The food bank, one of the largest in the nation, has been shipping about 3 million pounds of food to 300 charitable organizations in the Greater Los Angeles area every month, she said.

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Lyn Mattox, a Los Angeles County fire inspector, said the hillsides stripped of soil-binding vegetation in the devastating brush fires of 1993 were still holding, “but the ground up there is starting to become saturated, and if these storms keep up, it’s very possible there will be some problems.”

Brack said the first rain from the approaching storm system should start falling by dawn today, with the heaviest downpours expected before noon, accompanied by winds that could gust up to 50 m.p.h. at higher elevations.

“There should be about an inch of rain in the coastal areas, with up to three inches of rain in the foothills,” he said. “That translates to a foot or more of new snow in the San Gabriel Mountains.”

Brack said that although the effects here will be substantial, the main force of the storm will hit Central and Northern California, where heavier precipitation and stronger winds are expected. He said that while ocean swells as tall as 13 feet are forecast off Southern California, swells of up to 27 feet are predicted north of San Francisco.

Waves 10 feet tall are expected to pound the beaches of Southern California, and officials warned of possible damage to oceanfront property.

Skies will remain at least partly cloudy over Southern California on Sunday and Monday, Brack said, and another storm could bring some heavy showers by Tuesday.

He said the continuing series of storms is the product of two jet streams converging over California.

“The one from the south is bringing in moisture,” he said. “The one from the north is bringing in storm energy. Where they converge, there’s a lot of rain.”