Landslides & debris flows
Landslides tend to happen where they've happened before. Learn the signs and the history of your slope.
Landslides can creep slowly and crack foundations, or move fast as debris flows that carry mud and boulders down canyons onto the alluvial fans where many Utahns live. Wet springs and burn scars raise the risk.
Why it matters in Utah
- Debris flows can occur with little warning. Fifteen people have been killed by debris flows in Utah; 13 died in two nighttime events. UGS (opens source in a new tab)
- The 1983 Rudd Canyon debris flow in Farmington deposited about 90,000 cubic yards of sediment, damaged 35 houses, and caused an estimated $3 million in damage. UGS (opens source in a new tab)
- Debris flows often follow wildfires, and alluvial fans, where flows deposit, are also favored building sites. UGS (opens source in a new tab)
- Many Utah landslides are considered dormant, but recent slope failures are commonly reactivations of older landslides. UGS (opens source in a new tab)
- Landslide insurance is generally not available, though debris-flow damage may be covered by NFIP flood insurance. Be Ready Utah (opens source in a new tab)
Who's most affected
- Homes on or below steep slopes, on benches, at canyon mouths, and on alluvial fans. UGS (opens source in a new tab)
- Areas below recent burn scars, especially during intense rain. UGS (opens source in a new tab)
- Anyone in canyons during heavy rain or rapid snowmelt.
What to do
1 Before
- Check your area on the UGS Geologic Hazards Portal. UGS (opens source in a new tab) Be Ready Utah (opens source in a new tab)
- Drain water from downspouts and driveways away from slopes; don't add water, fill, or yard waste to steep slopes. Be Ready Utah (opens source in a new tab)
- Consult a licensed engineering geologist or geotechnical engineer before altering slopes or buying on a hillside. Be Ready Utah (opens source in a new tab)
- Make an evacuation plan; for fast debris flows, leaving is often the only protection. Be Ready Utah (opens source in a new tab)
2 During
- If you suspect active movement, evacuate and contact local fire, police, or public works. Be Ready Utah (opens source in a new tab)
- Listen for rushing water, cracking trees, or a faint rumbling that grows louder, and watch for a sudden change in stream flow or water turning from clear to muddy. If caught, move uphill fast. Ready.gov (opens source in a new tab)
- Never ignore an evacuation order. Be Ready Utah (opens source in a new tab)
3 After
- Stay away from the slide area; more movement can follow. Ready.gov (opens source in a new tab)
- Listen to local radio or TV for the latest emergency information. Ready.gov (opens source in a new tab)
Warning signs on your property
Be Ready Utah lists signs that land may be moving. One sign isn't proof, but several together deserve a professional look: Be Ready Utah (opens source in a new tab)
- Cracks in walls, floors, soil, sidewalks, or foundations; doors and windows that suddenly stick
- Tilted or bent trees, leaning utility poles, sagging or taut lines
- New springs, wet ground, or water seeping into the basement
- Bulging retaining walls; broken water or sewer lines