Debris Flow Hazards Debris flows occur when debris such as trees, soil, and rocks is Flash Floods caught up in a flash flood. Debris flows can move at over 60 miles After the Fires per hour on steep slopes. In an unburned watershed, vegetation anchors soil in place. After fires burn away the vegetation, nothing is left to hold the soil in place during heavy rain. Rapid erosion during intense rain increases the chances for debris flows People can become trapped in Wildfires can wreak havoc on vehicles or caught up in the communities and forests, but debris flows many people are unaware of the Debris flows carrying branches, dangerous flash flood hazard they trees and boulders can be very National Weather Service leave behind. This pamphlet ex- damaging to homes and other amines how flash flooding risks structures Weather Forecast Office may be heightened in and near Billings, MT burned areas for many years after 2170 Overland Ave a fire and what actions Billings, MT 59102 you can take to be better informed and Phone: (406) 652-0851 www.weather.gov/billings prepared. National Weather Service Billings, MT Vehicle trapped in a debris flow Increased Flash Flooding Risk Flash Flooding Impacts How the Soils Change & What You Can Do Burned soils develop a waxy Flash flooding is much more likely characteristic near the surface after a wildfire due to loss of which repels water vegetation and changes in the Severely burned soils that obtain physical properties of the soil this characteristic are called Steeper slopes and severely burned hydrophobic landscapes are at the greatest risk, Rain that falls onto hydrophobic but every area is unique soil runs off more quickly Contact your local National because it cannot soak in Flash flooding after fires can Weather Service office or occur in areas that may not The volume of runoff from Emergency Management officials typically flood, or where one rainfall is much greater from to learn about the risk in your area wouldn’t expect to see flooding hydrophobic soils Explore flood insurance options at Flash flooding is a hazard that www.floodsmart.gov The combination of these two affects motorists, pedestrians, properties of burned soil (more Be prepared www.Ready.gov and structures. Appropriate runoff and faster runoff) leads to measures should be taken by all increased risk of flash flooding Monitor your local weather to avoid flood dangers. forecasts in advance to be ready for This trait of hydrophobic (burned the possibility of intense rainfall Just a reminder as you approach and waxy) soils can remain for and flash flooding flooded roads and streams many years leading to flooding “Turn Around, Don’t Drown.” During times of high intensity issues well into the future rainfall, stay informed of the weather and the latest watches and warnings by monitoring: Water droplet on hydrophobic soil that does not 1. NOAA Weather Radio soak into the soil because of the waxy coating. 2. Your surroundings 3. www.weather.gov/billings 4. Local News Media Oregon State University image. .