Thursday, February 13, 2025

LA County Deploys Unprecedented Storm Runoff Protection System Ahead of Major Storm

Officials brace for most intense rainfall of recent atmospheric river series with unprecedented environmental protective measures

Los Angeles County crews have rushed to implement extensive and unprecedented measures to protect Altadena and Pasadena from flooding, mudslides, and debris flows as the region faces its third and most intense atmospheric river storm this week.

The National Weather Service has issued a flash flood watch through Thursday evening, with the heaviest rainfall expected Thursday afternoon into Friday.

The Eaton Fire burn zone devastation creates a situation fraught with potential dangers and damage.

“This is unusual. We don’t … want any debris to end up in the streets. We do use the streets to drain the area clear flow,” Mark Pestrella, Director of Public Works and Chief Engineer of the Los Angeles County Flood Control District, said at livestreamed meeting early Wednesday morning.

The County has installed thousands of linear miles of K-rails and hundreds of thousands of sandbags in a temporary system across burn scar areas, including the Palisades and Eaton fire zones. These structures are designed to capture debris and sediment before they can enter storm drains.

“And then when we know it will reach the streets, we’re diverting those flows. First, separating sediment from them so that what will occur is you will see sediment in the street captured, sitting in the street, keeping it from getting into our waterways and into the ocean,” Pestrella explained.

Public Health officials have issued warnings about residents’ exposure to hazardous materials in burn areas.

“Fire debris can contain asbestos, lead hazardous chemicals, and fine particular matter,” officials said during the briefing, urging residents to wear appropriate PPE or avoid these areas during debris removal.

The County’s 154 debris basins have been prepared for the storm, though some areas face particular challenges. The Eaton wash dam has reached concerning levels, prompting plans to remove 150,000 cubic yards of material. Officials will conduct 24/7 trucking operations for two weeks starting next Monday, February 17, in the Sierra Madre area.

Residents can report storm-related issues to the Public Works Dispatch Center at 800-675-HELP.

For real-time updates and preparation information, visitors can access ready.la county.gov.