safety tips to prepare for mudslides
how fast can they go?
Debris flows (also referred to as mudslides, mudflows, or debris avalanches) generally occur during intense rainfall on water-saturated soil. They usually start on steep hillsides as soil slumps or slides that liquefy and accelerate to speeds as great as 35 miles (56 km) per hour. Debris flows commonly begin in swales (depressions at the top of small gullies) on steep slopes, making areas downslope from swales particularly hazardous.
What you can do
Prior to intese storm
- Become familiar with the land around you. Learn whether debris flows have occurred in your area by contacting local officials, State geological surveys, or departments of natural resources, and university departments of geology. Slopes where debris flows have occurred in the past are likely to experience them in the future.
- Watch the patterns of storm-water drainage on slopes near your home, and note especially the places where runoff water converges, increasing flow over soil-covered slopes. Watch the hillsides around your home for any signs of land movement, such as small landslides or debris flows or progressively tilting trees.
- Contact your local authorities to learn about the emergency-response and evacuation plans for your area and develop your own emergency plans for your family and business. If a flood is likely in your area, listen to the radio or television for information. (See AlertMarin below)
During intense storms
- Stay alert and stay awake! Many debris-flow fatalities occur when people are sleeping. Listen to a radio for warnings of intense rainfall. Be aware that intense short bursts of rain may be particularly dangerous, especially after longer periods of heavy rainfall and damp weather.
- If you are in areas susceptible to landslides and debris flows, consider leaving if it is safe to do so. Remember that driving during an intense storm is hazardous.
- Be especially alert when driving. Embankments along roadsides are particularly susceptible to landslides. Watch the road for collapsed pavement, mud, fallen rocks, and other indications of possible debris flows.
If you suspect imminent landslide danger
- Contact your local fire, police, or public works department.
- Inform affected neighbors.
Alertmarin - Emergency alert program
Get alerted about emergencies and other important community news by signing up for our Emergency Alert Program. This system enables us to provide you with critical information quickly in a variety of situations, such as severe weather, flooding, wildfire, earthquakes, missing persons and evacuations of buildings or neighborhoods.You will receive time-sensitive messages wherever you specify, such as your home, mobile or business phones, email address, text messages and more. You pick where, you pick how. For more information and to register, visit www.alertmarin.org.