According to Arizona Firewise, “a defensible space is an area, either man-made or natural, where the vegetation is modified to slow the rate and intensity of an advancing wildfire. This space is the property owner’s first defense in the protection of their property against the ravages of wildfire because it will slow the advancement and the intensity of the approaching fire and creates a space for the firefighters to work safely and also protects the surrounding forest areas from a fire beginning in a home or other structure. The size of the defensible space can vary according to the characteristics of the area to be defended, but it is recommended that a minimum of 75 feet be established around a home. (If the structure is on a slope, the space needs to be larger).
How To Create Defensible Space
The first line of defense is to remove all flammable vegetation within 15 feet of all structures. This measurement is done from the outside edge of the eaves of any structure on the property. This distance needs to be increased to 30 feet if the property is in an area of chapparal vegetation.
In this area, the reduction of flammable materials or fuel is implemented. First, remove all dead, dying trees and shrubs. Thinning and pruning the shubs and trees that are left is important as it eliminates the fuels that may cause fire to threaten the home.
Thin all trees within the space to 10-12 foot crown spacing. This means thinning the trees so that the tops (or crowns) of the trees are no more than 10-12 feet away from each other.
Mow or remove dry grass and weeds to a height of no more than 6 inches for at least 30 feet from the buildings.
Remove “ladder fuels” (i.e. small trees, shrubs and other flammable vegetation) from beneath all trees, and prune tree branches to 10 feet above all such fuels. Trim branches that reach over the roof and remove all within 15 feet of the chimmney. Clean all pine needles and leaves out of gutters.
Stack firewood at least 30 feet away from all structures and clear all flammable materials at least 10 feet away from all woodpiles.
Propane tanks and other fuel storage containers at least 30 feet away from all structures, and clear flammable vegetation away from these containers.
Dispose of all “slash”, or woody debris, through chipping or by burning. Contact local fire officials for infomation on proper methods of slash burning.
Your defensive space must be maintained regularly, at least once year, as vegetative growth will return.
Questions about creating or maintaining a defensible space should be directed to your local fire department, State Lands Fire Management, or county extension office.
Below is a Defensible Space and Firewise Annual Checklist
(Provided by College of Agiculture & Life Sciences, The University of Arizona)
Issued by Alix Rogstatd, Fire Education Specialist
Defensible Space and Firewise Annual Checklist
__ Trees and shrubs are properly thinned and pruned within the defensible space. Slash from the thinning is disposed of.
__ Roof and gutters are clear of leaves, needles, and other debris.
__ Branches overhanging the roof and chimney are removed.
__ Chimney screens are in place and in good condition.
__ Grass and weeds are mowed to a low height.
__ An outdoor water supply is available, complete with a hose and nozzle that can reach all parts of the house.
__ Fire extinguishers are checked and in working condition.
__ The driveway is wide enough. The clearance of trees and branches is adequate for fire and emergency equipment. (Check with your local fire department.)
__ Road signs and your name and house number are posted and easily visible.
__ There is an easily accessible tool storage area with rakes, hoes, axes and shovels for use in case of fire.
__ You have practiced family fire drills and your fire evacuation plan.
__ Your escape routes, meeting points and other details are known and understood by all family members.
__ Attic, roof, eaves and foundation vents are screened and in good condition. Stilt foundations and decks are enclosed, screened or walled up.
__ Trash and debris accumulations are removed from the defensible space.
For further information on defensible space for the Prescott area, go to:
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