Post-Fire Flood Risk

IMG_2026You may be at risk of flooding due to recent wildfires that have burned in your area.

Normally, vegetation absorbs rainfall, reducing runoff. However, wildfires leave the ground charred, barren, and unable to absorb water, creating conditions ripe for flash flooding and debris flows. Flood risk remains significantly higher until vegetation is restored—up to five years or longer after a wildfire.

Even modest rainstorms over a burned area can result in flash flooding downstream. These floods are typically much larger than they would have been before the wildfire. Flooding is likely to be much more extensive following wildfire, endangering properties previously considered safe from flooding. These floodwaters typically transport surface debris such as downed trees, boulders, mud and gravel.

If you live or work in – or travel through – drainages, valleys, or anywhere downstream of a wildfire, EVEN IF YOU HAVE NOT BEEN AT RISK FOR FLOODING IN THE PAST, you need to be aware of the new flooding hazard. There are steps you can take to reduce flood risk, and resources that may be available to assist you. See the Before, During, and After Flood quick links on this page for more information.