Purpose

This page helps households recognize landslide and debris-flow risk, understand official warning triggers, and avoid the most common fatal decisions.

Scope

This is household-level safety guidance only.

It does not provide engineering advice, drainage design, slope stabilization methods, or rescue instruction.

Authority Override

If authorities issue evacuation orders, debris-flow warnings, exclusion zones, or road closures, follow them immediately.

Do not return until officials confirm it is safe.

FAST FACTS THAT AFFECT LIFE SAFETY

• Landslides and debris flows can occur suddenly, especially during heavy or prolonged rainfall, rapid snowmelt, or after earthquakes.

• Debris flows can move faster than a person can run and often follow creeks, gullies, and drainage channels.

• Many fatalities occur when people are inside homes or vehicles located in the flow path.

• Areas burned by wildfire can face increased landslide and debris-flow risk for months to years due to loss of vegetation.

• Roads are often the first infrastructure damaged, delaying rescue and isolating communities.

WHY LANDSLIDES ARE SO DANGEROUS

Rapid onset

• Slides often occur with little warning once soil becomes saturated or destabilized.

Extreme force

• Mud, rocks, trees, and debris move as a dense mass capable of destroying buildings and vehicles.

Repeat events

• A first slide may be followed by additional movement minutes or hours later.

Secondary hazards

• Broken gas lines, downed power lines, damaged water systems, and blocked roads are common after a slide.

HIGH-RISK LOCATIONS

• The base or top of steep slopes, bluffs, or cliffs

• Along creeks, rivers, and drainage channels that exit steep terrain

• Below burn scar areas following wildfires

• Areas with recent construction, grading, or soil disturbance

• Mountain highways, road cuts, and known rockfall zones

WARNING SIGNS THAT REQUIRE IMMEDIATE ATTENTION

If you observe any of the following, leave the area if it is safe to do so and contact local authorities:

• New cracks in soil, pavement, foundations, or retaining walls

• Tilting or leaning trees, fences, or utility poles

• Sudden changes in creek flow, especially water turning muddy or carrying debris

• Accumulation of logs, branches, or rocks in channels

• Unusual rumbling, cracking, or grinding sounds

• Doors or windows suddenly sticking or misaligning

These signs do not guarantee a slide will occur, but they are recognized government warning indicators and should be treated seriously.

WHAT NOT TO DO

This section is the priority.

• Do not remain in known landslide or debris-flow zones during heavy rain, rapid snowmelt, or freeze–thaw cycles.

• Do not drive through flowing mud, debris, or water crossing a road. Turn around and follow official detours.

• Do not stop, park, or linger in signed landslide or rockfall areas, especially during storms.

• Do not go near creek channels or drainage gullies during intense rainfall. These are common debris-flow paths.

• Do not return to an area after an initial slide. Secondary slides are common.

• Do not enter damaged structures or areas with exposed utilities after a slide.

EVACUATE OR SHELTER DECISION FRAMEWORK

Evacuate immediately if:

• Authorities issue an evacuation order, landslide warning, or debris-flow advisory.

• You observe strong warning signs such as increasing rumbling, visible slope movement, or sudden surges of muddy water.

• You are in a valley, gully, or channel during extreme rainfall or sudden runoff changes.

Shelter in place only if:

• You are on stable ground outside slope and channel hazard areas.

• Roads are blocked and authorities advise staying put.

Critical safety note

• In some situations, moving during an active slide may be more dangerous than taking immediate cover. If you cannot safely evacuate, follow official guidance and seek the safest immediate protection available.

BUFFER ZONES AND SAFER POSITIONING

Decision framing only. Not engineering instruction.

• Distance from slopes is the most effective risk reduction strategy.

• Avoid being below steep slopes or bluffs during high-risk weather windows.

• Treat creeks, ravines, and drainage channels as no-go areas during intense rainfall.

• Use local and regional hazard maps, where available, to identify areas your household should avoid during storms.

ESSENTIALS FOR LEAVING EARLY

Focus on items that prevent death or medical crisis:

• Identification and essential documents

• Medications and critical medical supplies

• Phone and backup power

• Flashlight and batteries

• Sturdy footwear and gloves

• Pet leash or carrier supplies

Do not rely on tools or equipment as a solution during an active slide. Avoidance and early relocation save lives.

OFFICIAL GOVERNMENT LANDSLIDE RESOURCES

Canada

https://www.canada.ca/en/services/policing/emergencies/preparedness/get-prepared/hazards-emergencies/landslides.html

https://www.canada.ca/en/services/policing/emergencies/preparedness/get-prepared/hazards-emergencies/landslides/how-prepare.html

https://natural-resources.canada.ca/science-data/science-research/landslides

British Columbia

https://www2.gov.bc.ca/gov/content/safety/emergency-management/preparedbc/know-your-hazards/landslides

United States

https://www.ready.gov/landslides-debris-flow

https://www.ready.gov/sites/default/files/2024-03/ready.gov_landslide_hazard-info-sheet.pdf

https://www.usgs.gov/programs/landslide-hazards/how-do-i-prepare-a-landslide

https://www.usgs.gov/programs/landslide-hazards/what-are-signs-landslide-development-what-do-i-do-if-a-landslide-occurs

Last Reviewed

February 2026