Creating Fire-Safe Defensible Space
by Denise Healy
Seasoned residents know the threat of forest fires to home and private property, as well as to the forest areas we all enjoy. We´re reading daily headlines about new wild fires and the damage they´re causing. Fire departments are enforcing laws pertaining to Defensible Space and insurance companies are choosing to not renew policies on properties that do not conform to defensible space guidelines.
But more importantly, people are realizing the benefit of creating defensible space to help protect their homes and investments. Being informed can help to take the mystery and fear out of the subject of protecting homes and property from the very real threat of wildfire. Being fire savvy requires us to know how to protect our personal interests. And it calls us to be an asset in helping to keep our community from experiencing the devastation of forest fire. Yet, knowing what it takes to be “Fire Safe” can be daunting.
According to “Living with Fire in Tuolumne County,” Defensible space is; “the area between a house and an oncoming wildfire where the vegetation has been modified to reduce the wildfire threat and to provide an opportunity for firefighters to effectively defend the house. Sometimes, a defensible space is simply a homeowner´s properly maintained backyard.
While our laws set defensible space at 100 feet or to the property line, defensible space is definitely site specific. The rule is, the steeper the terrain, the wider the area needed. Fire personnel have general guidelines for the amount of area needed to maintain a fire safe distance. A slope of 0-20% is considered level to gently sloping. 21-40% is moderate to easy to walk in and to work, and above 40% is considered steep, a challenge to climb. Checking with a local fire department can help figure the defensible space that an individual house site needs.
People erroneously think defensible space means space that is devoid of all vegetation. While bare ground does prevent the approach of oncoming wildfire, it creates other problems such as erosion, compaction and unsightly landscapes. Sensible placement and management of vegetation on the property will allow for both fire safety and beauty. It is also important to note that landscape that is kept green and watered will help in the effort to retard an approaching fire and should be part of an overall fire prevention strategy. In fact, fire agencies refer to the 30 foot boundary around buildings as needing to be “lean and green.”
Use of fire-retardant building materials and fire-resistant shrubbery is a part of a fire safe strategy. Fire retardant plants include: trees such as bigleaf maple, western redbud, or the California live oak; shrubs like yarrow, artemisia, trumpet vine, daylilies, privet or oleander. Ajuga reptans or Mexican evening primrose is a good choice for ground cover. Call the Tuolumne County Master Gardener office at 533-5696 for a list of less-flammable plants.
An “oasis” area should surround the home. Landscape that requires the most water is best planted here, providing a green and moist area which would help keep a fire at bay. The Home Ignition Zone is considered to be the home plus 10 feet. Lumber, firewood, and other flammables should not be stored here.
Beyond the home, to thirty feet, is an area of landscaping using moderate water. In this area all dead or dying plants and other combustible materials need to be removed. This includes firewood, scrap lumber, pine needles and anything else that is flammable. Landscape should be well watered and kept in shape, weeds minimized. Branches of shrubs and trees that are dead or decaying should be trimmed, keeping their habit open and loose. Avoid conifers that are highly flammable. Trees close to the home should clear the roof, allowing at least 10 feet of space between the roof and the branches. Keep the roof and rain gutters free of leaves and debris.
From 30 feet to a minimum of 100 feet from the house (or to the property line) is an area that needs to be kept clear of brush and debris in order for fire hazard to be minimal for the home´s safety. Trees should be limbed 8 to 10 feet from the ground. If shrubs are under the trees, the trees should be limbed to 8 to 10 feet higher than the tallest shrub. This eliminates what is called “ladder fuel”. Fire heat moves upward, so removal of ladder fuel reduces the ability of fire to climb into trees. Do not allow the seasonal accumulation of dead vegetation to build up. Maintain this area yearly to keep the volume of vegetation low. In this area remember to place plants so that there are pockets of space between groupings of plants to create fuel breaks.
Once the needs of private property are addressed, each citizen can further cultivate fire prevention habits by following these guidelines:
Vegetation burning is currently suspended
Do not use lawn mowers on dry grass. The blades can scrape on rocks, causing a spark. Ensure that spark arresters are working on all equipment.
Park vehicles so that the exhaust system does not come in contact with dry grasses or weeds.
Make sure vehicles are properly tuned up so they don´t back fire and cause a spark to fall into dry vegetation
Do not throw burning cigarettes out of car windows. (Better yet, quit smoking.)
Notify the electric power company when dead trees or overhanging limbs endanger electric wires.
Be sure barbecues are used well away from overhanging tees and shrubs.
Notify the proper authorities if a fire is spotted, or you see smoke in an unusual place.
Remember “Defensible space is Sensible space.” Implementing ways to reduce the threat of fire only takes a short period of time. Rebuilding and reforesting takes years. As Smokey aptly put it more than 40 years ago, “Only you can prevent forest fires.” Working together we can.