Emergency Preparedness and Response
Landslides and Mudslides
The purpose of this resource page is to provide comprehensive guidance for individuals, families, and communities to prepare for, respond to, and recover from landslides and mudslides effectively.
Landslides occur when gravity overcomes the stability of the slope, causing materials to move rapidly downhill. They can be classified into different types based on their movement and the materials involved, including:
- Debris flows: Fast-moving masses of loose mud, rock, and organic material.
- Rockfalls: Sudden free-fall of rocks from steep cliffs or slopes.
- Slumps: Slow-moving slides of water-saturated earth and rock that leave a curved scar on the slope.
Factors increasing landslide risk include deforestation, construction on unstable slopes, and changes in water drainage patterns.
Mudslides, also called debris flows, are fast-moving landslides made up of water, rock, soil, and debris. They pose significant risks to people, homes, and infrastructure, especially in areas with steep terrain or loose, saturated soil. Mudslides occur when heavy rainfall, rapid snowmelt, or activity destabilizes slopes, causing a sudden flow of debris down hillsides. Mudslides can happen quickly and without warning, making them particularly dangerous. Key factors that increase the risk of mudslides include:
- Prolonged or intense rainfall
- Recent wildfires or deforestation
- Poor land management and construction
- Earthquakes or seismic activity
Home and Property Protection
Landslides and mudslides are unpredictable and can be devastating, but with the right preparation, you can protect yourself, your family, and your property. The Federal Emergency Management Agency provides information on how you can protect different areas of your home. Note: This is not a complete or comprehensive list.
- Slope stabilization: Plant deep-rooted vegetation to help anchor soil and prevent erosion.
- Retaining walls: Install retaining structures to support steep slopes and divert water away from unstable areas.
- Drainage improvements: Ensure proper drainage systems around your home such as clearing gutters to reduce water accumulation.
- Reinforce your home: When rebuilding, use techniques to make your home more resilient to future mudslides, such as improved drainage systems and foundation reinforcements.
- Work with local authorities: Engage with local planning and zoning offices to ensure safe land use practices that reduce the risk of future events.
Susceptible Populations
Landslides and mudslides occur in every state and U.S. territory including the Appalachian Mountains, the Rocky Mountains, the Pacific Coastal Ranges, and some parts of Alaska and Hawaii. Any area composed of steep slopes or very weak geologic materials will likely experience landslides.
U.S. Landslide Inventory and Susceptibility Map
The U.S. Geological Survey provides an interactive, high-resolution map of landslide susceptibility throughout the United States and its territories. [url; USGS]
Federal Programs
USGS Landslide Hazards Program
The U.S. Department of the Interior Geological Survey Landslide Hazards Program provides information to homeowners and governments on causes of ground failure and suggests mitigation strategies to reduce long-term losses from landslide hazards.
Understanding Recent Landslides and Mudslides
The articles below describe recent landslides or mudslides and provide explanations on their occurrences.
Hurricane Helene
The Landslide Hazards Program provides information about the landslides produced by Hurricane Helene. [url; USGS, 2024]
Pedersen Lagoon
The Landslide Hazards Programs explains a landslide in Alaska and the tsunami that followed afterwards. [url; USGS, 2024]
Latest page update: July 31, 2025.