Loss of life, property, and resources due to WUI fires can be reduced if planners, developers, fire agencies, and homeowners work together to define, enforce, and maintain reasonable fire safety standards. Reducing or removing fire hazards in the WUI requires an assessment of potential risks, programs and standards for fire safety, and fuel management in the wildland urban interface. These three sets of activities may be conducted at national, state, local or individual levels.

Barriers to fire migitation

Virginia Department of Forestry Fire Danger is Low Sign

Despite the availability of programs and options for reducing hazards, there are many barriers to fire mitigation. Even in areas prone to wildfires, many residents prefer to wait for the event to occur and then respond, rather than take precautions to minimize risk (Jackson 1981). WUI residents may even deny that a wildfire is likely to occur or discount its potential impact. Some people feel that WUI fires are inherently uncontrollable and the resulting damage is essentially random, resulting in little support for investments in firefighting infrastructure and steps to safeguard their properties (Winter, Vogt, and Fried 2000). If a home is destroyed, insurance spreads the costs among a large group of people, encouraging continued residence in high-risk areas. Several insurance companies are beginning to withdraw coverage if high risk factors are not corrected. Actually experiencing a wildfire may be the only modifier of risky behavior (Beebe and Omi 1993).

National standards for creating low fire risk conditions in the Wildland Urban Interface (WUI) have primarily come through the NFPA (National Fire Protection Association) and Firewise Communities Program. Those standards are then implemented through various state or local programs that promote voluntary actions, community action programs, or governmental ordinances and other regulatory mechanisms. The NFPA maintains standards for infrastructure, water supply, and utility lines in residential developments that aim to reduce fire risks.

A House in a Firewise Community in
Oden, Arkansas

Some of the NFPA fire safety standards for infrastructure are:

• adequate access routes for subdivisions, preferably two entrances to the subdivision
• right-of-ways maintained with a minimum width of 60 feet
• dead ends limited to 800 feet in length
• cul-de-sacs with not less than 45 feet radius driveways present with a minimum 10 feet width and clear of vegetation
• bridges must have a minimum 20-ton gross weight load capacity
• roads must be identified with non-combustible signs at all intersections and clearly visible within 100 feet of the intersection
• roads must be maintained for all weather travel

A Dry Hydrant

NFPA water supply fire safety standards include:

• water distribution mains on which fire hydrants are located should have a minimum diameter of 6 inches
• fire hydrants meet the standards of the responsible fire authority with regards to type, size, and location
• individual private water supplies should have a minimum water storage capacity of 2500 gallons within 500 feet of the structure
• tanks and cisterns have a 4.5" diameter capped male hose connection
• garden hose bibbs available near the house that can reach all parts of the structure

A Home with Firewise Landscaping
in Upper Bluff Mountain, Tennessee

Electrical power system fire safety standards set by NFPA include:

• electrical lines installed underground in new developments
• underground power cables at least 30 inches below the surface
• overhead power cables free of encroaching vegetation within 6 feet

These and other NFPA 1144 standards have been adopted by both state and local organizations for community development. As new communities are developed and older ones are retrofitted to create fire-safe communities, fire prevention managers emphasize that meeting fire-safe standards can still be aesthetically pleasing to residents.

Community action programs

Firewise Communities USA is a fire education project of the NWCG (National Wildfire Coordinating Committee), administered by the NFPA whose goals are to prevent and reduce losses to WUI fire and foster community participation in applying Firewise principles. Firewise Communities USA was developed as a way to help stop the wildfire disaster cycle which is the phenomena where fire risks in the WUI remain just as high after a fire as they were before because people who have lost a home in a WUI fire re-build it in the same spot as the original home using money from homeowners insurance or low-cost loans. The Firewise Communities USA program provides citizens with the knowledge necessary to maintain an acceptable level of fire readiness and ensures that firefighters will be able to make efficient use of their equipment during a wildland fire emergency. The national Firewise program has conducted workshops in many states to promote local planning for fire safety. The collaborative workshops include local citizens, financial and insurance organizations, local government officials and fire agency representatives.

A Firewise Workshop in Austin, Texas

Firewise Communities USA recognizes communities or neighborhoods that demonstrate the spirit, resolve, and willingness to take responsibility as a partner in wildfire protection. As of 2004, 20 Firewise Communities had been recognized in the South. Firewise Communities representatives visit recognized communities to assess the site, establish a committee consisting of homeowners and local fire agency officials, create site-specific plans, and implement solutions. Common practices recommended by the Firewise Communities USA program include: removing excess vegetation from road shoulders, replacing wood shake roofs with a non-flammable Class-A alternative (such as asphalt shingles or metal), removing highly flammable trees and shrubs and planting low flammable trees and shrubs, stacking firewood away from homes, and creating a minimum three foot fuel-free area on all sides of structures.

Governmental actions

The fire management policies and regulations of state, county, and local governments guide land use decisions. Local governments exercise their authority over land use through zoning ordinances (Kundell and others 2002) which are increasingly used to apply fire safety standards to new and existing residential developments. In 2004, Louisa County, Virginia approved subdivision guidelines/ordinances for communities in wildfire sensitive areas. The guidelines apply to any new subdivision or construction and are designed to protect the life, safety, and welfare of citizens and property. The guidelines address design and development plans, defensible space, fuel modification, liquified petroleum gas installations, roads, driveways, overhead power lines, and fire hydrants. Recommended fuel modification treatments include the removal of any pine or cedar trees within 20 feet of any residential dwelling and the removal or pruning of vegetation or woody growth under trees.

In 2003, Alachua County, Florida, added an amendment to its Comprehensive Plan that incorporates wildfire mitigation to “protect life, property, and the economy by eliminating or minimizing the present and future vulnerability to wildfire hazards” (Alachua County 2003). The amendment addresses current areas of wildfire hazard and requires new developments to complete a wildfire mitigation plan to include defensible space, fuel breaks, plant material suggestions, and the placement of structures. This plan is subject to review and approval by the Alachua County Fire Rescue Department. Other requirements include outdoor sprinkler systems, fire-resistant building materials or treatments, landscaping with appropriate vegetation, appropriate roads for access by fire fighting equipment, and increased public awareness of the benefits of prescribed burning.

Fuel management modifies the hazard posed by vegetation and structures by:

• reducing the available fuel (dead and living) in broad areas using prescribed fire or other methods
• creating defensible space by converting the vegetation to a less-flammable type and distribution that is less hazardous
• by modifying structural features

Despite the availability of programs and options for reducing hazards, there are many barriers to fire mitigation.

Fuel reduction methods

Fuel reduction techniques are used to decrease hazardous fuels (i.e., flammable vegetation). Fuel management is especially critical in forest ecosystems located adjacent to residential areas because of the increased risks to people and property, enhanced resource values, and the increased difficulty of fire control and suppression (Kalabokidis and Omi 1998). Fuel modifications may be broadcast across large areas, applied to small selected lots, or designed as strips of various widths to impede fire spread into a developed area. Mechanical, chemical and biological methods are used to reduce hazardous fuel loads. Some examples of common fuel reduction methods follow:

A Wildland Urban Interface Home That
Needs to Reduce Fire Risks

• Prescribed burning is the careful application of fire to achieve land management goals. Fire is a natural component of most southern ecosystems that encourages the growth of some native plants and enhances wildlife habitat in addition to reducing accumulated fuels. Prescribed fire can usually be completed at comparatively low-cost. Disadvantages to using prescribed fire include smoke management and public health issues, limitations on the number of acres that can feasibly be burned each year, the necessity for repeat treatments as vegetation grows back, and the risk of fire escapes. Smoke problems from a prescribed burn in the wildland urban interface are minimized by burning during favorable, daytime, smoke dispersal conditions.
• Herbicides have longer lasting effects on the vegetation than other methods, and they may be the only treatment for invasive exotic species. Herbicides do not modify the soil structure, nor do they enhance the regeneration of most fire dependent organisms unless chemical treatments are combined with prescribed burning. Herbicides do not reduce dead biomass accumulations; in fact, they temporarily increase dead fuels and the potential fire danger for one to three years. Herbicides have comparatively moderate costs and generally low public acceptance.
• Mechanical fuel treatments such as mowing, disking, roller chopping, and hand removal are generally risk free, have a high level of public acceptance, and are the only methods that modify or disturb soil, if that is needed. Disadvantages to using mechanical treatments include the necessity of repeat treatments, moderate to high costs, limitations on wet sites and steep slopes, follow-up burning is often required, and personal safety concerns associated with the use of hand tools such as machetes and chainsaws.
• Using livestock to maintain fuels at an acceptable level is an uncommon, but effective method. Livestock grazing offers a semi-natural alternative that is usually lower cost and safer than other methods. Pastures that have recently been converted to pine plantations are often still dominated by grasses and grazing cattle reduce competition and fuel load. Disadvantages to using livestock include the need for fencing and water supply for the animals, local grazing restrictions, and re-sprouting vegetation.

Defensible space

Arkansas Firewise Home of the Month
(February 2004)

Defensible space is the area of modified vegetation between wildland fuels and structures that can reduce the intensity of fires close to structures, provide firefighters the chance to stop a wildfire quickly and efficiently, and reduce a structure fire when firefighting personnel and equipment are not immediately available to help (Bailey 1991; Randall 2003). Homeowners need to take proactive, preventative actions to reduce the wildfire risk to their property by modifying structures and creating a defensible space. Materials for roofing, siding, decks, and vents, plant selection, landscape design, and maintenance are the most critical elements for a fire-safe home (Hagen 1993). Defensible space can be a 30-foot clearing with tree islands or a greenbelt surrounding a planned community. A study in Florida showed that structures with less than 10 feet of brush clearance were 60% more likely to burn during a wildfire than homes with at least 30 feet of cleared brush (Abt and others 1987). Homes with non-flammable roof coverings (asphalt shingles, metal, tile) that are surrounded by 30 to 60 feet of modified vegetation are over 85% more likely to survive a wildfire than homes with flammable roofs and no vegetative clearance (Foote and others 1991). Defensible space can include firewise plants and native species that are low in flammability. Firewise plants have a high moisture content in the leaves and branches, broad and thick leaves, open and loose branching patterns, deciduousness, low amounts of dead materials, and low amounts of resin. Some less flammable plants are dogwood, viburnum, redbud, sycamore, magnolia, oaks, red maple, wild azalea, sweetgum, winged elm, black cherry, persimmon, wild plum, and ferns. Fire-prone plants to avoid near structures are junipers, young pine trees, cedars, palmetto, wax myrtle, rhododedendron, mountain laurel, tall ornamental grasses and yaupon holly (U.S. Department of Agriculture, Forest Service 2003). Landscaping tips for mitigating fire hazard and creating defensible space include:

• Space plants carefully - use shrub islands or patches of perennials rather than continuous beds or plantings.
• Prune plants regularly - thin trees so branches do not touch each other.
• Remove all ladder fuels - trim lower branches up to 10 feet on tall trees, remove vines from trees and keep shrubbery away from pine trees so a fire in surface fuels cannot climb up these ladder fuels to the treetops.
• Remove dead leaves and other litter from around trees, shrubs and vines, and from a 3-5 foot strip next to the structure.
• Provide the landscape with sufficient moisture when fires are imminent

Fire resistant construction tips

Structural modifications to improve fire resistance include:

Cedar Shake Roofs Replaced with
Non-Flammable, Class-A Roofing

• metal, asphalt shingle, or tile roof
• balconies and decks constructed of materials approved for 1-hour fire resistance in accordance with the American Society of Testing Materials Standard E 119
• attic vents, soffit vents, foundation openings and other such openings covered with 1/8" mesh noncombustible corrosion-resistant metal screen
• street address clearly posted on the main street
• dual or triple pane thermal or tempered glass windows and glass doors, or fireproof shutters for windows
• sprinkler systems installed on roof or around eaves.

Risk is defined as the likelihood that a particular home or community will experience a fire in the wildland urban interface in the foreseeable future (Long and Randall 2004). The assessment of risk helps establish priorities for: 1) guiding community development, 2) assisting landowners with their landscaping and home design, 3) planning fuel modification treatments, and 4) allocating fire suppression resources. The traits of a home and its surrounding environments that can affect the risk of fire include:

Remove Excess Fuels from Roadsides

• types, arrangement, size, and volume of vegetation and fuels
• likelihood of ignition (either by lightning or humans)
• design and construction materials of individual homes
• infrastructure such as roads, signs, water sources, and utilities
• topography and related environmental factors
• resource or asset values that would be impacted by fire

The importance of these 6 factors varies depending on whether the risk assessment protocols have been developed for the region and states, communities, or individual home sites.

Regional and state level risk assessments

Completed in 2004, the Southern Wildfire Risk Assessment (SWRA) is a regional effort commissioned by the Southern Group of State Foresters that allows agencies and organizations to assess the overall potential for wildfire and its associated problems (Southern Group of State Foresters 1998). The SWRA establishes a process to assess fire hazards and the values to be protected. The assessment provides managers with a strategic view of the region to improve public safety and protect homeowners from property losses. The SWRA uses Geographical Information Systems (GIS) to create data layers that are analyzed to classify and identify areas of relative danger from wildfire risk. The GIS layers include: population density, historic fire occurrence, values at risk, topography, fuel types, available suppression resources and response times, and structural density (Space Imaging 2003).

The Florida Division of Forestry’s Fire Risk Assessment System (FRAS) completed in 2003 is an information system that assists fire managers in prioritizing mitigation projects throughout the state and also functions as a planning tool for local fuel reduction efforts (McLellan and Brenner 2003). FRAS is composed of the following GIS layers: wildfire susceptibility, population density, land value, and fire response accessibility. These factors are weighed, ranked, and combined to develop levels of concern. FRAS is flexible to allow the adjustment of input values and can be run iteratively to produce new estimates of risk.

The Virginia Department of Forestry (VDOF) developed a similar GIS model that incorporates maps of wildfire risk with areas of moderate to high population, and forest cover. The wildfire risk map input layers include: slope, aspect, landcover, distance to railroads, distance to roads, population density, and historical fire occurrence. Synthesizing the spatial relationship of these and other features allows VDOF to concentrate their prevention education, resource allocation, and emergency response efforts where fire poses the greatest risk.

Risk assessment for communities

The most efficient and cost-effective time to make the preparations to protect the home from fire is during the initial development of a wildland property. Florida’s DOF distributes a helpful guide for home protection to developers and fire departments that suggests how to plan access routes, utilities and fuelbreak zones.

Standards and rating systems for the different factors that influence community susceptibility to a fire have been developed by the National Fire Protection Association (NFPA), the Firewise program, the U.S. Department of the Interior, the International Fire Code Institute, and a number of different states. Many community risk assessments developed by individual states or local governments follow the NFPA standards or have modified them to fit particular situations.

NFPA 1144 Standard for Protection of Life and Property from Wildfire was developed to provide minimum planning, construction, maintenance, fire education, and management elements for the protection of life, property, and other values that could be threatened by wildfire (NFPA 2002). NFPA 1144 recommends a numerical rating system to define the relative contributions to hazard severity of the following factors, listed by the possible score each individual factor can contribute to the severity rating with 0 being the lowest severity:

• 0 - 25 points each: roofing materials, vegetation (types and defensible space)
• 0 - 10 points each: slope, water sources, siding, and deck construction
• 0 - 7 points each: subdivision design (ingress, road width, grade, turnarounds, lot size, signs)
• 0 - 5 points each: special topographical and weather features; utility placement

Risk assessment for individual homes

Whether or not a wildfire ignites a home depends on the length of time it is exposed to high heat or firebrands, direct flames, and the home’s properties as a fuel (Long and Randall 2004). Firebrands that land on a roof, attached structure (e.g. deck) or vegetative fuels adjacent to a structure account for the majority of homes burned in the wildland urban interface (U.S. Department of Agriculture, Forest Service 2003).

Homeowners can assess and rank their individual levels of risk from an approaching wildfire by using one of several risk assessment programs. These programs focus on only those factors over which individual homeowners have control:

• The Wildfire Risk Assessment Guide for Homeowners in the Southern United States focuses on two sets of risk factors:  the vegetative fuel component and the structural
  

  Reducing Fire Risks Around the Home
  component. The fuel component includes ratings for the natural plant communities and defensible space around homes. The structural component includes ratings for firebrand ignition factors (i.e., wood shingles, wood deck); indirect ignition factors (i.e., slope, wood fence); and heat-related or direct ignition factors (i.e., wood siding, vinyl siding). A numeric score is determined for each factor and the total risk rating is related to four levels of fire risk (low to very high) (Long and Randall 2004).
• The USDA Forest Service’s Structure Ignition Assessment Model (SIAM) uses an analytical approach that relates the potential for sustained structure ignitions to the location (rather than the potential for structural survival) and characteristics of adjacent fires and the structure’s materials and design (Cohen 1995). The model is based on research and the principle that a homes characteristics and the 100 to 200 foot area immediately surrounding a home determine a homes ignition potential during a severe wildfire.
• The University of Florida developed a simple system in 1999 that allows landowners unfamiliar with risk assessment to determine the ignition risk to their home using a checklist of risk factors (Monroe and Long 1999). A home is then ranked as being at low, medium, or high risk of wildfire.
• The USDA Forest Service has also developed the NED DSS (Decision Support System) fire risk program for homeowners and landowners across the South to evaluate and mitigate their particular landholding. The NED DDS applies to both wildland urban interface and rural forest situations and is based on vegetation conditions, local topography, and structural characteristics.