16-05-2025
Living Near a Burn Scar: What to Know About Future Risks
After wildfires sweep through parts of Los Angeles County and surrounding areas, the burned hillsides and open spaces left behind can continue to affect nearby neighborhoods.
These scorched areas, or burn scars, are more vulnerable to flooding, erosion, and other environmental changes, especially during rainy months. If you live near recently burned land, here's what to know about the risks and how to take simple steps to help protect your property.
A burn scar is the charred land left behind after a wildfire. The blackened soil is stripped of vegetation and has changed chemically, altering the way it functions.
When a wildfire burns down trees, grass, and bushes, it removes the speedbumps that slow rainfall, reduce runoff, and hold soil in place. With the vegetation gone and land now bare, there's an increased risk of erosion, landslides, and water contamination.
Rainwater slides quickly across burn scars because wildfire heat makes the soil hydrophobic, meaning that it repels water instead of absorbing it. Without vegetation to slow the runoff, rainfall can quickly pick up ash, loose soil, and debris, which then become debris flows, often described as 'liquid concrete.'
Even less than half an inch of rain per hour can trigger flash flooding and debris flows. These events are most common in the first two years after a fire, but the risk can last longer depending on the terrain and how quickly vegetation recovers.
Burn scars can contaminate local water systems. Ash, heavy metals, and other toxic debris may wash into rivers, reservoirs, and private wells. Burned structures add chemicals and toxic materials to the runoff.
During and after wildfires, do-not-drink notices are put in place to protect residents until proper testing is completed. Even with an all clear, more bans or boil notices may be put in place by local officials during later storms in areas with burn scars.
Standard homeowners insurance on its own does not cover flood damage from mudslides or debris flows. Consider purchasing National Flood Insurance Program (NFIP) coverage, especially if you live below a burn scar.
During forecasted heavy rainstorms, take extra precautions to avoid damage from floods. Install sandbags, retaining walls, or debris barriers to divert water away from your home and keep drains and gutters clear to prevent backups.
If you live downhill, downstream, or near a canyon or drainage path, it's especially important to stay informed. Sign up for alerts from LA City Emergency Management and LA County Ready LA Alerts to know about floods in your area.
If heavy rain has already begun or is in the forecast, don't wait for an official evacuation order — leave as soon as you feel unsafe.
