The City of Orange enjoys a natural “wildland” environment on the eastern end of the city. This environment affords wonderful views, a feeling of getting away to the country, and plenty of opportunities for recreation. However, the City of Orange, as well as California as a whole, has experienced very real and sobering property losses due to wildland fires. Most of us remember the firestorms of 1993. Orange lost eight homes in the Stagecoach Fire, while Laguna Beach was hit even harder with the destruction of 366 homes. These losses caused the fire service to look long and hard at the safety of structures in the urban-wildland interface.
Fire behavior is dictated by three factors: 1) the lay of the land, 2) weather, and 3) fuel. Southern California experiences some of the fiercest wildland fires in the nation largely due to the chaparral native to the region, and also due to the infamous Santa Ana winds. Fortunately, we can tame fire behavior by controlling the fuel in and around our structures.
Controlling the types, density, and moisture content of plants – or fuel – is called “fuel modification.” By modifying the fuel around our homes, we can create a “defensible space” in which firefighters can work. The fuel is modified in four zones: A, B, C, and D.
The “D” zone is essentially the thinning of the naturally growing vegetation by 30%. All dead and dying plants are removed, as well as undesirable species. This is the zone designed to initially slow the fire, and is generally 50’ wide.
The “C” zone is thinned to 50% to further slow the fire. It is also 50’ wide.
The “B” zone is irrigated, and planted with a selected number of fire resistant plant species. Combustible construction is not allowed in the “B” zone. This zone is a minimum of 50’ in width.
The “A” zone (also known as the “set back” zone) is closest to structures and, as such, is the most highly fire resistant. This zone is 20’ wide, automatically irrigated, contains no combustible construction, and is pruned to reduce fuel load. Builders occasionally place this zone within the back yards of houses when planning neighborhoods.
Fuel modification zones are carefully designed fire breaks between wildland areas and structures – namely homes. The zones are initially proposed to the fire department by the builders, in blueprint form, when neighborhoods are developed. The plans are then approved by fire department plan checkers just as any other fire protection system would be. Homeowners’ associations generally assume the responsibility to maintain those zones as originally approved by the fire department. If the “A” zone falls within homeowners’ back yards, the association is responsible for ensuring that the homeowner maintains the approved landscaping, and that no combustible construction occurs.
The mission statement of the fire department is “to prevent or minimize the loss of life and property from the adverse effects of fire, medical emergencies, and dangerous conditions created by man or nature.” One way this mission statement is fulfilled is by ensuring the safety and well being of families living in the urban-wildland interface. Nature can be fierce and unforgiving. Fuel modification is the most effective step our community can take to prevent loss of life and property in the future.
Please contact Fire Safety Specialist Janna Doty via email, or contact her through the Fire Prevention Bureau at (714) 288-2541 with any questions or comments you might have.