LOS ANGELES – Wildfires have burned through more than 50,000 acres of Los Angeles County since January 7. Now, weather authorities are forecasting possible rain showers for the weekend. It may be a good time for residents of areas impacted by the wildfires to prepare for the hazardous by-products of fire and rain: flooding, debris flows and mudslides. 

Large-scale Wildfires Can Lead to Flooding and Debris Flows 

Where intense fires occur, soils can develop a top layer that repels water due to charred remnants of organic material. Normally, live vegetation sucks up rain, reducing runoff, but wildfires leave the ground barren. Unable to absorb the rain, the soil succumbs to flooding. The flood risk can remain elevated from two to five years. 

Debris flows are fast-moving slurries of material — water, rock, soil, vegetation, and even boulders and trees — that rush downhill. Mudslides flow down slopes that become saturated and collapse. Californians who live downhill or downstream from burnt areas are at the greatest risk for dangerous debris flows. Even smaller debris flows can be dangerous.

What Individuals in Burn-scarred Areas Can Do

Post-fire flooding can be unpredictable because surface changes from the fire are not always obvious. Wildfire survivors should learn to recognize the signs of coming flood events: soil that is crunchy to walk on; increased slope erosion; or even unusual sounds from the surrounding terrain — mudslides and debris flows can be loud.  

When the rain comes:

• With rain in the forecast, elevate your valuables to higher points in your home, pack a “go-bag” and make an exit plan.
• Watch where the water goes. If you see gullies, rapid flooding, debris flows or mudslides in your area, check local media for alerts and prepare to evacuate. The California Governor's Office of Emergency Services (Cal OES) actively monitors flooding activity and issues alerts when an area is at risk.
• Avoid debris; it can include sharp and heavy hidden objects that can cause serious injury and worse.
• Heed the guidance of local authorities. With flooding events come health hazards, including broken utility lines and disrupted infrastructure. Sign up for local emergency alerts.

Just one inch of floodwater can cause costly damage to your home, but most homeowners insurance does not cover flood damage. You may consider purchasing flood insurance from the National Flood Insurance Program (NFIP), which is managed by FEMA. You can purchase flood insurance coverage at any time. However, there is a 30-day waiting period after you’ve paid the premium before the policy becomes effective. For more information about the NFIP, visit fema.gov/flood-insurance or call 877-336-2627.