After a wildfire or during intense storms, the landscape can change quickly—and dangerously. Southern California’s steep terrain, especially in areas like Burbank, is vulnerable to sudden flows of mud and debris that can threaten homes, roads, and lives. Preparing ahead of time and knowing what to watch for during storm events can make all the difference when every second counts.
What Is a Debris Flow?
A debris flow—often called a mudslide in the media—is a fast-moving mix of mud, rocks, sand, soil, water, and air that rushes downhill due to gravity. For it to be classified as a debris flow, more than half the solid material must be larger than sand grains and capable of flowing like a liquid.
A mudflow is similar, but contains finer, sand-sized particles and more water, making it faster and more fluid. The terms “mudslide” and “debris flow” are often used interchangeably in the media, but they describe different types of movement.
Characteristics
Debris and mud flows are like wet concrete – thick, fast-moving, and packed with destructive power. They can strike with little or no warning, much like flash floods. In places like Burbank, large debris flows are more likely to occur on hillsides that have been burned by wildfires, where the vegetation and root systems that normally stabilize the soil have been destroyed.
How to Prepare
- Make a plan for what you and your household will do in an emergency, and have a disaster preparedness kit ready.
- Use sandbags to direct water and debris away from your home, especially if you live near slopes or recently burned hillsides. For sandbag information, visit the City of Burbank Public Works Flood Control page or call (818) 238-3800.
- Watch nearby hillsides for warning signs like tilting trees, shifting ground, or changes in water runoff patterns.
During Heavy Storms
- Stay alert. Many fatalities occur at night—keep a battery-powered radio or NOAA Weather Radio handy for warnings.
- Listen for unusual sounds like cracking trees or shifting rocks—these could signal debris is on the move.
- Watch creeks or streams for changes in water color or flow speed—muddy water could indicate upstream debris activity.
- Avoid driving during intense storms; roadside slopes are especially prone to collapse. Be on the lookout for mud, rocks, or fallen debris.
If You Suspect Danger
- Call 9-1-1 immediately.
- Warn your neighbors. They may not be aware of the risk.
- Evacuate early. Don’t wait—get to higher, safer ground. If you're inside, try to move to an upper floor away from slopes.
Getting out of the path of a debris flow is the most important thing you can do to protect yourself and your family.
