What are some of the warning signs of a potential landslide or debris flow?

After a fire and before and during the rainy season, property owners in impacted areas should examine their properties and be aware of the following landslide warning signs:

  • Springs, seeps, or saturated ground in areas that have not typically been wet before.
  • New cracks or unusual bulges in the ground, street pavements, or sidewalks.
  • Soil moving away from foundations.
  • Ancillary structures such as decks and patios tilting and/or moving relative to the main structure.
  • Tilting or cracking of concrete floors or foundations.
  • Broken water lines and other underground utilities.
  • Leaning telephone poles, trees, retaining walls, or fences.
  • Offset fence-lines.
  • Sunken or dropped-down road beds.
  • Raid increase in creek water levels though rain is still falling or just recently stopped.
  • Sticking doors and windows, and visible open spaces indicating door-jambs or frames are out of plumb.
  • A faint rumbling sound that increases in volume as the landslide nears.
  • Unusual sounds, such as trees cracking or boulders knocking together, may indicate debris movements.

For more information, visit the USGS landslide preparedness page

Show All Answers

1. How should we prepare our property for rain?
2. How does fire contribute to flooding and erosion hazards?
3. What does fire do to the soil?
4. What are hydrophobic soils?
5. How does fire turn soil hydrophobic?
6. How do I tell if my soil is hydrophobic?
7. What is a flash flood?
8. What is debris flow?
9. What is a mudflow?
10. Debris flows and mudflows sound similar. How are they different?
11. What is the difference between a debris flow and a landslide?
12. Why are debris flows and mudslides so dangerous?
13. Where do debris flows occur?
14. What are the flooding and debris flow impacts that could potentially occur after a fire? For how long after the fire am I facing potential threats?
15. What type or size of storm event should I be concerned with?
16. What are some of the warning signs of a potential landslide or debris flow?
17. What effect does fire have on the trees on my property?
18. What steps should I take before removing trees on my property?
19. Can I remove trees that do not pose a health and safety hazard?
20. Does it matter what type of trees I would like to remove?
21. Can I remove burned trees and install a vineyard or other project in their place?
22. My property did not burn. Should I be concerned with post-fire debris flow and/or erosion?
23. Are there other organizations and agencies that can provide financial and technical assistance tree removal and watershed protection?
24. How do I protect my property from erosion, flash flooding, mudflows, and debris flow?
25. I'm concerned that using straw mulch as erosion control will increase my fire risk.
26. What is the purpose of the debris flow mitigation advice that Engineering offers in fire-affected areas?
27. I rent or lease my home. Will Napa County notify me and provide me debris flow mitigation advice?
28. Will Napa County install the erosion control measures for me on my property?
29. Where can I get assistance in placing erosion control measures on my property?
30. What do I do about debris that deposits on my property?