Landslide
Landslides occur across all U.S. states and territories, triggered by factors such as earthquakes, storms, wildfires, and human land modifications. They range from slow-moving slides that cause gradual property damage to fast, deadly events that strike with little warning. Wildfires can increase landslide risk for years, making certain areas more vulnerable. Protecting against landslides depends on their type, with zoning, professional inspections, and proper design helping mitigate risks, though evacuation is often necessary for fast-moving debris flows.
- Sign up for Humboldt Alert emergency notifications.
- Have your emergency kit ready to sustain you and your household for at least 2 weeks.
- Make an emergency plan for your household, including your pets, so that you and your household know what to do, where to go, and what you will need to protect yourselves from landslides.
- Prepare for landslides by following proper land-use procedures – avoid building near steep slopes, close to mountain edges, near drainage ways or along natural erosion valleys.
- Become familiar with the land around you. Learn whether debris flows have occurred in your area by contacting local city or county officials. Slopes where debris flows have occurred in the past are likely to experience them in the future.
- Get a ground assessment of your property if possible.
- Consult a professional for advice on appropriate preventative measures for your home or business, such as flexible pipe fittings, which can better resist breakage.
- Protect your property by planting ground cover on slopes and building retaining walls.
- In mudflow areas, build channels or deflection walls to direct the flow around buildings. Be aware, however, if you build walls to divert debris flow and the flow lands on a neighbor’s property, you may be liable for damages.
- If you are at risk of property damage from a landslide, talk to your insurance agent. Debris flow may be covered by flood insurance policies from the National Flood Insurance Program.
- Changes can occur in landscape such as patterns of storm-water drainage on slopes (especially the places where runoff water converges) land movement, small slides, flows, or progressively leaning trees.
- Doors or windows stick or jam for the first time.
- New cracks appear in plaster, tile, brick, or foundations.
- Outside walls, walks, or stairs begin pulling away from the building.
- Bulging ground appears at the base of a slope.
- Water breaks through the ground’s surface in new locations.
- Fences, retaining walls, utility poles, and/or trees tilt or move.
- A faint rumbling sound that increases in volume is noticeable as the landslide nears.
- The ground slopes downward in one direction and may begin shifting in that direction under your feet.
- Unusual sounds, such as trees cracking or boulders knocking together, might indicate moving debris.
- Collapsed pavement, mud, fallen rocks, and other indications of possible debris flow can be seen when driving (embankments along roadsides are particularly susceptible to landslides).
- Pay attention and listen to emergency alerts, Humboldt Alert notifications [link] and NOAA weather radio for current emergency information and instructions.
- Stay alert and awake during storms that could trigger landslides, as many landslide-related incidents happen while people are asleep.
- Listen for unusual sounds that might indicate moving debris, such as trees cracking or boulders knocking together.
- Recognize that if you are certain a debris flow is approaching, it may be too late to evacuate safely. Avoid crossing roads with flowing water or mud and never cross a bridge if a flow is approaching, as it can quickly increase in size and speed.
- Avoid river valleys and low-lying areas.
- If you do get stuck in the path of a landslide move uphill as quickly as possible. If you are unable to escape, curl into a tight ball and protect your head.
- Wait until officials say it is safe to go home.
- Stay away from the slide area. There may be danger of additional slides.
- Watch for flooding. Floods sometimes follow landslides and debris flows because they may both be started by the same conditions.
- Check for injured and trapped persons near the slide, without entering the direct slide area. Direct rescuers to their locations.
- Report broken utility lines and damaged roadways and railways to appropriate authorities. Reporting potential hazards will get the utilities turned off as quickly as possible, preventing further hazard and injury.
- Check a building’s foundation, chimney, and surrounding land for damage to assess the safety of an area.
- Replant damaged ground as soon as possible since erosion caused by loss of ground cover can lead to flash flooding and additional landslides in the near future.
- Seek advice from a geotechnical expert for evaluating landslide hazards or designing corrective techniques to reduce landslide risk.