Southern California Rain Helps Firefighters but Creates Risk of Toxic Ash Runoff
After weeks of windy and dry weather, rain has fallen in parched Southern California and is expected to aid firefighters who are mopping up multiple wildfires. But potentially heavy downpours on charred hillsides could bring new troubles such as toxic ash runoff.
Preparations Underway
Los Angeles County crews spent much of the past week removing vegetation, shoring up slopes, and reinforcing roads in devastated areas of the Palisades and Eaton fires, which reduced entire neighborhoods to rubble and ash after breaking out during powerful winds on January 7.
Rainfall and Debris Flows
Most of the region was forecast to get around an inch (about 2.5 centimeters) of precipitation over several days, but "the threat is high enough to prepare for the worst-case scenario" of localized cloudbursts causing mud and debris to flow down hills, the National Weather Service said on social media. "So the problem would be if one of those showers happens to park itself over a burn area," weather service meteorologist Carol Smith said. "That could be enough to create debris flows."
Flood Watches and Cleanup Efforts
Rainfall that began late Saturday was expected to increase Sunday and possibly last into early Tuesday, forecasters said. Flood watches were issued for some burn areas, while snow was likely in the mountains. Los Angeles Mayor Karen Bass issued an executive order last week to expedite cleanup efforts and mitigate the environmental impacts of fire-related pollutants. LA County supervisors also approved an emergency motion to install flood-control infrastructure and expedite and remove sediment in fire-impacted areas.
Toxic Ash Runoff
Fire crews filled sandbags for communities, while county workers installed barriers and cleared drainage pipes and basins. Officials cautioned that ash in recent burn zones was a toxic mix of incinerated cars, electronics, batteries, building materials, paints, furniture, and other household items. It contains pesticides, asbestos, plastics, and lead. Residents were urged to wear protective gear while cleaning up.
History of Post-Fire Debris Flows
Concerns about post-fire debris flows have been especially high since 2018, when the town of Montecito, up the coast from LA, was ravaged by mudslides after a downpour hit mountain slopes burned bare by a huge blaze. Hundreds of homes were damaged, and 23 people died.
Ongoing Wildfires
While the impending wet weather ended weeks of dangerous gusts and reduced humidity, several wildfires were still burning Saturday across Southern California. Those included the Palisades and Eaton fires, which killed at least 28 people and destroyed more than 14,000 structures. Containment of the Palisades Fire reached 81% on Saturday, and the Eaton Fire was 95% contained.
Conclusion
The rain in Southern California is expected to bring relief to firefighters, but it also poses a risk of toxic ash runoff and debris flows. Authorities are taking precautions to mitigate these risks, and residents are urged to take necessary precautions while cleaning up. The region is still recovering from the devastating effects of the recent wildfires, and the rain is a reminder of the importance of preparedness and safety.
FAQs
Q: What is the risk of toxic ash runoff?
A: The ash in recent burn zones is a toxic mix of incinerated materials, including pesticides, asbestos, plastics, and lead. Residents are urged to wear protective gear while cleaning up.
Q: What is the threat of debris flows?
A: Localized cloudbursts could cause mud and debris to flow down hills, creating debris flows. Authorities are preparing for the worst-case scenario.
Q: How is the region recovering from the recent wildfires?
A: Cleanup efforts are underway, and authorities are working to expedite the removal of sediment and debris in fire-impacted areas.
