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Defensible Space for Farms or Ranches

Defensible space describes the area surrounding a structure or asset where vegetation and combustible materials are carefully maintained to eliminate pathways that wildfire can burn directly to structures, reduce potential for ignition of nearby vegetation and combustible materials from embers, and provide a safe zone to easily evacuate and for firefighters to defend structures.

DSPACE
A) Before and B) after implementation of the three-zone defensible space strategy.

Preparing your defensible space does not have to be costly. Below are recommended actions you can take to implement an effective defensible space strategy within different sones within 0-100 feet of your structures.

Zone
Recommended Actions
Zone Zero

0-5 ft from structure

  • Remove and dispose of woody vegetation and combustible mulches.
  • Relocate wood piles, unprotected hay, and other flammable material.
  • Consider concrete, gravel, or rock mulch around buildings to keep the area free of vegetation.
  • If fences are attached to the building, upgrade the attachment point with a noncombustible panel or gate.
  • Aboveground fuel tanks should also have a 5-foot noncombustible zone (Zone Zero).
Zone One

5-30 ft from structure

  • Remove and dispose of all dead and dying vegetation.
  • Space shrubs two times the height of mature plants, increasing spacing on steeper slopes.
  • Remove limbs of tall trees from 6-10 feet off the ground. For younger, smaller trees, prune over time, but only remove branches in the lower one-third of the tree.
  • Remove branches of trees that are within 10 feet of a structure.
  • Mow or graze grasses to a maximum height of 4 inches.
Zone Two

30-100 ft from structure

  • Remove and dispose of all dead and dying vegetation.
  • Thin trees so all branches or groupings of trees are separated by at least 10 feet.
  • Limb lower branches of taller trees up to a height of at least 10 feet.
  • Mow or graze grasses to a maximum height of 4 inches.
  • Store hay or other flammable feedstock on bare ground. If not possible, mow or graze fuels next to storage areas.
  • Aboveground fuel tanks should be kept on a noncombustible pad and clear of all vegetation.
  • Large equipment should be spaced 20 feet apart from each other and adjacent structures and be kept on a noncombustible surface (bare ground, gravel, concrete).

 

Additional Resources

Check out these additional defensible space-related resources from UC ANR Fire Network Members and our colleagues!