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Climate and Environment

How LA County Prepares For Rain and Major Storms

A cityscape is shrouded in dark and rain.
Pedestrians on Sunset Avenue in Silver Lake during a small reprieve from the rain on Wednesday, January 4, 2023.
(Samanta Helou Hernandez
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Preparation for major storms in Southern California happens year round.

How LA County Prepares For Massive Rainfall — Like The Storm Hitting Us Now

Los Angeles County Public Works is the agency responsible for keeping many area roadways clear and flood-free. It oversees roads, building safety, planning, waste disposal, and infrastructure meant to stop flooding in unincorporated areas of the region.

LAist talked to the agency's public information officer, Steven Frasher, about how the county helps residents — and how residents can help protect themselves — during a big storm.

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Patrols, With Community Help

L.A. County Public Works deploys trucks with blades on the front— like a snowplow — to clear rocks and other debris from county roadways. If you see a blocked roadway or dark traffic signal, call the 24-hour hotline at 800-675-HELP (4357) to report it.

Stopping Floods In The Foothills

The county has a network of more than 200 debris basins. “These are like neighborhood dams,” Frasher said. “As water rushes out of the mountains [debris basins] capture water and debris… and allow the water to seep out in a manageable pace.”

When the storm season ends, usually in late spring or early summer, those debris basins are cleared out, Frasher said.

Water Conservation

Southern California needs fresh water, and storms provide it — but, Frasher says, the first storms of the year don’t often provide much, because “your trees, your shrubs on the mountainside, they're thirsty and and take up that a lot of that first rainstorm.”

But the recent rain means more saturated ground. “Your city streets are part of that flood control infrastructure,” he said, as street water drains into spreading grounds or into the San Gabriel and L.A. rivers for later use.

How effective are those techniques? Here's how much winds up in the ocean, and here’s a little history lesson.

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Monitoring Burned Area

Burned areas "are always a concern because there isn't greenery to hold on to the soil,” Frasher said. “This coming storm adds an extra layer of concern because there [have] been these previous storms that have soaked into the soil a bit.”

Several areas the county is keeping a close eye on are Lake Hughes, Azusa, Duarte and the parts of the San Gabriel and Antelope Valleys where the Bobcat Fire burned in 2020.

Residents can sign up for emergency alerts and see the latest mud and debris flow forecast online.

A big pile of sand with a shovel sticking out of it.
Residents can bring bags to fill up from piles of sand at their local fire stations, like this one at LAFD's Station 28 in Porter Ranch.
(Ryanne Mena

Providing Sandbags

Los Angeles County fire stations offer sandbags to residents — stock up before the storm gets worse. You can also get sand for sandbags from any LAFD fire station.

Be advised that you might need to bring your own shovel and/or your own bags — it's worth calling ahead.

What questions do you have about the weather we're experiencing?
A massive winter storm is hitting Southern California. We're here to answer your questions.