Pamela And, a La Canada resident, stands next to a temporary barrier she
purchased. (Photo by Madeleine Scinto)

Sandbags lined streets in La Canada. (Photo by Madeleine Scinto)

Weeks after the Station Fire burned 250 square miles, Los Angeles County now braces for potential flash floods and mudslides as the fall's first rains rolled into the area Tuesday.

The National Weather Service said Tuesday flash flood advisories are in effect for the areas recently burned by the fires.

The county Public Works Department has been preparing foothill communities, especially La Crescenta, for mudslides the past three weeks, by setting up several thousand feet of concrete barriers, spokesman Kerjon Lee said.

Engineers have also visited 400 homes in La Crescenta, advising people on how to protect their property and explaining how many sandbags each house needs. The public works department of La Canada Flintridge has been taking similar measures, even barricading certain homes with up to 500 sandbags.

The fire departments of La Canada Flintridge and La Crescenta are distributing tens of thousands of sandbags and are sending fire trucks around neighborhoods as a precaution.

While the storm is expected to end Wednesday, Captain Bruce Davis of the La Canada Fire Department warned residents about the ongoing threat of mudslides.

"If this rain doesn't produce what they're thinking, there will be more later," he said. "Get your valuables out sooner rather than later. Be prepared."

Because of the fires that ravaged L.A. County in August and September, mudslides prove particularly threatening this year. The fires created a three-inch layer of waxy ash and completely scattered the roots of any vegetation that could hold the weakened soil together.

When it rains, the water carries debris like boulders and tree trunks down canyons, dragging dirt along with it to create a mudslide.

The U.S. Geological Survey found that Pacoima Canyon, Big Tujunga Canyon, the Arroyo Seco, the west fork on the San Gabriel River and Devils Canyon all have an 80 percent likelihood of mudslides, which could spill into La Canada Flintridge and La Crescenta.

The Public Works Department and the county Flood Control District have been working together to manage the geological problems. The flood district controls the dams and storm drains to prevent mass flooding. Public Works manages the foothill debris basins and recently has been reinforcing them with concrete.

The La Crescenta basin alone can hold up to 5,000 cubic meters of debris and is designed to catch mudslides coming down the canyon before they reach homes.