Create a defensible space
to protect lives and property!
Wildfire Mitigation is the implementation of various measures designed to minimize the risk and destructive effects of a wildfire on your property. Some measures are designed to modify the forest environment and reduce the fuel load surrounding a structure or group of structures that puts the structures at risk from destruction by a wildfire. Others focus on modifying the construction of a structure itself or changing its location to improve its ability to withstand a wildfire without being dependent upon fire suppression resources. These efforts principally apply to the construction or remodeling of a home, and are governed by local building codes.
We will focus on efforts to reduce the fuel load, which lessens the intensity of the fire. Another goal is to keep the fire on the ground. Once a crown fire develops, it is nearly impossible to stop without aircraft support.
Defensible space is the area around a structure where fuels and vegetation are treated, cleared or reduced to slow the spread of wildfire towards the structure. This also provides firefighters enough room to safely access and defend the structure from approaching fire. Creating an effective defensible space involves developing a series of management zones in which different techniques are used. As a mountain property owner, your first defense against wildfire is to create and maintain a defensible space around each building on your property.
Zone 1 – The Safety Zone:
This area is where you will do the most modification and treatment. It consists of an area of 15 -30 feet around the structure, in which all flammable vegetation is removed. This 15 – 30 feet is measured from the outside edge of the home’s eaves and any attached structures, such as decks. Within this zone, several specific treatments are recommended:
- · Plant nothing within three to five feet of the structure, particularly if the building is sided with a flammable material. Opt for weed barrier covered with rock or gravel instead.
- · Make sure there are no areas of continuous grass adjacent to plantings in this area and frequently prune plants in this zone to ensure vigorous but low growth. Keep grasses mowed to four to six inches.
- · Remove dead branches, stems and leaves.
- · Enclose or screen decks with metal screening and extend gravel coverage under the decks. Do not use the area under decks for storage of anything that will burn.
- · Do not store firewood in this area, particularly in sheds built onto the structure.
- · Keep foundations, decks, stairs, gutters and roofs clear of leaves, pine needles and debris.
- · Remove all trees from this zone, or if you keep trees, consider them part of the structure and extend the distance of the defensible space accordingly. Isolate trees from each other, prune to at least 10 feet above ground, and remove branches within 10 feet of any chimney.
- · Remove all ‘ladder fuels’ from beneath the trees. Ladder fuels are small shrubs, trees, limbs and other materials that allow a fire to climb on the tree crown of branches and foliage.
Zone 2 – The Transition Zone:
This is an area of fuel reduction and a transitional area between Zones 1 and 3. The size of Zone 2 will vary depending on the slope of the ground where the structure is built. The defensible space should extend from a minimum of 75 feet from the structure (on flat ground) to 125 feet or more on sloped ground. Within this zone, the arrangement of vegetation (fuel) should be modified. This will help reduce the continuous fuel surrounding a structure and also enhance home safety and the aesthetics of the property.
- · Remove stressed, diseased, dead or dying trees and shrubs.
- · Thin and prune the trees and large shrubs in this zone so that there is at least 10 feet of distance between the crowns.
- · Thin along both sides of your driveway all the way to your main access road.
- · Blend the treatment of Zones 1 and 3 by gradually decreasing the thinning of trees as you near the outer part of Zone 2.
- · Mow or cut down grasses through the growing season to keep them no higher than six to eight inches. This is especially important in the fall when grasses dry out and after the spring thaw, when snow is gone, but before plants green-up.
- · Stack firewood uphill or at the same elevation as the structure, but at least 30 feet away. Keep flammable vegetation at least 10 feet away from the firewood pile. Dispose of excessive slash and other dead vegetation by hauling away, chipping, or piling and burning. See discussion on fire restrictions and burn permits later.
Zone 3 – The Management Zone:
This is an area of traditional forest management and is of no particular size. It extends from the edge of your defensible space to your property boundaries. In this area, you are encouraged to manage your forests in a more traditional manner. The actions you take will be determined by your objectives for your property. At minimum, you may want to:
- · Remove trees that are diseased, insect-infested, and those of poor form or low vigor.
- · Thin trees for forest health. Maintain age and species diversity.
These actions will sanitize and improve
the health of the forest on your land.
Lyons Fire Mitigation Team:
Lyons Fire will conduct a free homeowners assessment and provide mitigation recommendations. (This does not provide sufficient documentation for the wildfire mitigation plan required to obtain a boulder county building permit.) Lyons Fire has a wildfire mitigation team that will perform mitigation projects such as thinning, limbing, removal of hazard trees, and constructing fuel breaks.
Contact 303-823-6611 to arrange for a cost estimate.
*NOTE* Homeowners are encouraged to improve ignition resistant construction of residences. Where possible or when remodeling, replace wood shake shingles, siding, decks, connecting fences and structures with ignition resistant materials.