Firewise, USA™ Site Recognition Program
Davis Mountains Resort – Fort Davis, Texas
Introduction
Firewise, USA™ is a voluntary community level program designed to provide an effective management approach for preserving wildland living aesthetics while promoting education, prevention, and safety from wildfires. For a community to be a part of this program they must accomplish several steps including: a risk assessment, development of an action plan, and an annual community investment. Going through these steps in the program prompts the entire community to think about wildfire and other emergency situations and plan ahead for them. Wildfires are inevitable, however through planning and regular preparation, a community can minimize loss of life and property to a wildfire. This document will fulfill the risk assessment section and will be valid for 5 years before the community will need to be reassessed.
The following community assessment is intended as a resource to be used by the Davis Mountains Resort Committee for creating a wildfire safety action plan. The plan developed from the information in this assessment should be implemented on a broad scale across the community in a collaborative manner, and updated or modified as needed, no less than every three years.
The Firewise USA program acknowledges that there are many values that lead a person to live in the Wildland Urban Interface (WUI) and that there may be a desire for certain flammable components to exist on their properties. Individual properties can have differing management goals; however, it is vital that homeowners understand the implications of choices they are making and direct implications that directly impact the ignitability of their home ignition zones during a wildland fire.
One of the main objectives of the Firewise USA program is for residents to focus on the factors that they can directly control. Becoming aware of the threat wildland fire presents and developing a plan of action is the most important step any landowner can take. After that, further implementation of fuel management and mitigation techniques will reduce the change of home or structure loss in the event of a wildland fire.
Assessment Process
This assessment was conducted by Regional Wildland Urban Interface Coordinator Kayla Driver of Texas A&M Forest Service on September 25th, 2024. Other Texas A&M Forest Service representatives in attendance were Area Operations Chief Mike Dunnivan, Task Force Coordinator Cody Lambert, and Resource Specialist Jeremy Williams. The site assessment included discussing local conditions, ongoing and future mitigation projects, scope and long-term efficacy of previous projects. Additionally, the team took a guided tour through the community to assess structure and asset vulnerability, along with broader ecological conditions and evaluation of current fuel collection sites.
Included in this written assessment are observations made while visiting Davis Mountains Resort. The assessment includes the ease with which ignitions could occur under severe wildfire conditions and how these ignitions might be avoided within home ignition zones of affected residents. The assessment does not focus on specific homes, but on the residential community as a whole.
Davis Mountains Resort is in the wildland urban interface, where undeveloped areas of natural contiguous fuels of vacant parcels are intermixed with structures and more rigorously maintained properties. Wildfires are inevitable and unfortunately are not a choice in where ignition takes place. The unknown variables within the scenario are when and where the fire will occur. By addressing community wide vulnerabilities, residents will be able to substantially reduce their exposure to loss. Relatively small investments of time and resources can greatly increase wildfire safety.
Site Description
The Davis Mountains Resort (DMR) is a community comprised of more than 9000 acres with 800 individual tracts and more than 600 property owners and 300 structures. There are currently an estimated 350 full-time residents within the community with a significant number of part-time residents who come to participate in recreational activities. The DMR has more than 75 miles of unpaved roads with an average elevation of 5600ft with their highest elevation estimated at 6500ft on Skyline drive. The DMR is a montane grassland with a mixed forest climax community featuring ponderosa pine, pinyon pine, juniper, as well as several oak species.
Definition of the Home Ignition Zones
A house often burns because of its interrelationship with its immediate surroundings. To avoid a home ignition, a homeowner must eliminate the wildfire’s potential relationship with the structure itself. This can be accomplished by preparing their structure to withstand ember attacks and minimizing the likelihood of flames or surface fire encountering the home itself or any attachments by interrupting the natural path fire takes in the home ignition zone. This zone includes a house and its immediate surroundings within 100 to 150 feet and Davis Mountains Resort Risk Assessment determines the potential for home ignition during a wildland fire. Changing a fire’s path by modifying a home ignition zone is an important task that can result in avoiding home loss.
The Immediate Zone of the HIZ includes the structure itself and the area within 5 feet surrounding it. This is the most important area in which to take immediate action as it is the most vulnerable to embers and where even small flames can come into direct contact with the structure. Both research and firefighter’s first-hand accounts tell us that a well-prepared Immediate Zone makes the biggest difference in home survivability and first responder safety. This can be completed by using rock mulch against structures and removal of vegetation or using fire resistant species. It is recommended that all trees overhanging structures, especially wooden decks, should be trimmed if possible. Trimming will break direct contact with wooden structures thus reducing crown connection and risks of accidental ignition.
While the first 0-5 feet away from the structure is important to embers, your intermediate 5–30-foot zone is where you can make the most difference in stopping a surface fire from approaching your home. Creating islands of vegetation in your landscaping to decrease the fire’s ability to move toward the structure. Firewood and other flammable items should be kept 30 feet or more from a structure when not actively being used, and potted vegetation should only be kept in this zone if alive and healthy. Patio furniture and other appliances should also be treated as fuel in the event of a wildfire. Store patio furniture pillows inside when not in use, and during times of high fire danger move flammable items such as grills, gardening supplies, and home improvement supplied to a garden or shed. Remember that porches and any attachments are part of the structure, thus are the starting point of the home ignition zones and their relative boundaries.
It is important to pay attention to bushes planted around a structure’s foundation. If these shrubs are not maintained by annual pruning to remove dead growth and keep growth from touching the structure, they can act as ladder fuel. Ladder fuels function as a stepping on point where a low intensity surface fire can climb vertically in a receptive fuel bed. The higher off the ground a fire is, the more risk to the structure and first responders. Ladder fuels include anything flammable growing or stored under another flammable objects. Spare lumber and firewood often act as ladder fuels when stored under wooden porches or near sheds much like how shrubs and small trees do the same when under or near mature canopies and near eaves, wooden fences, etc. When choosing a new ornamental shrub consider something with less dense branching patterns, and low volatile oils such as those found in evergreens. Keep shrubs healthy, pruned, and away from vulnerable spots in structures like windows and vents that could fail under high heat or allow embers into a structure. The area 30-100, and up to 200 feet, from the home is identified as the extended zone. The goal of management in this area is not to eliminate fire but to interrupt fires’ path and keep flames smaller and on the ground. To achieve this, it is recommended to dispose of heavy accumulations of ground litter or debris as these areas of collected fuel are an energy sink where heat can sit and even act as a ladder fuel. In this area it is important to keep trees pruned appropriately and have smaller branches pruned up to generally around one and half the height of surrounding fuels or objects. For example, if your grass is a foot tall then there should be a foot and a half of clearance between the grass and tree limbs. Please note this example excludes any ladder fuels, as it is recommended these be completely removed in residential areas. Trees located between 30 and 60 feet from the home should have at least 12 feet between canopy tops. While trees 60 to 100 feet from the home should have at least 6 feet between canopy tops. These distances are designed so that if ladder fuels do ignite single tree, then the space between canopies reduces the risk of carrying fire from canopy to canopy causing an aggressive crown fire. Thus, limiting the progress to the lower intensity burning fine fuels, typically grasses.
Characteristics of a Severe Wildland Fire that Threatens the Area
Fire intensity and spread rate depend on the fuel type and condition (health, moisture content, etc.), weather conditions prior to and at time of ignition, as well as the topography. Generally, the following relationships hold between the fire behavior and the fuel, weather, and topography.
▪ Fine fuels, defined as fuel with a diameter less than 1/4in (ex. grasses, needles, twigs), ignite more easily and spread faster with higher intensities than coarser fuels, generally fuels greater than 1/4in in diameter (ex. large branches, logs, shrubs). For a given fuel, the more there is and the more continuous it is, the faster the fire spreads and the higher the intensities. Fine fuels take a shorter time to burn out than coarser fuels.
▪ The weather conditions affect the moisture content of the dead and live vegetative fuels. Dead fine fuel moisture content is highly dependent on the relative humidity and the degree of sun exposure. The lower the relative humidity and the greater the sun exposure, the lower will be the fuel moisture content. Lower fuel moisture produces higher spread rates and fire intensities.
▪ Wind speed significantly influences the rate of fire spread and fire intensity. The higher the wind speed, the greater the spread rate and intensity.
▪ Topography influences fire behavior principally by the steepness of the slope. However, the configuration of the terrain such as narrow drainages, saddles and so forth can influence fire spread and intensity. In general, the steeper the slope, the higher the uphill fire spread and intensity.
Anticipated wildfires in the Trans-Pecos region of Texas are expected to be driven by the combination of high wind speeds, low relative humidity, and long periods of time with elevated temperatures. The combination of these weather characteristics with dry fuels such as grasses, shrubs, and trees, especially those near a house, can often lead to structure loss. Due to the rugged terrain common in this area, access for structural and wildland firefighters is often an issue. Fire in the mountains can be expected to move quickly uphill in vegetated canyons and will often have unpredictable movement due to shifting wind patterns manipulated by changing topography.
Initial Observations and Recommendations
The fire resiliency of structures within the Davis Mountains Resort will be heavily dependent on the fuels within the Home Ignition Zone and how resistant the structures are to embers. Homes in the Davis Mountains Resort differ greatly in size, structure type, and materials. Some of which do have rated non-combustible roofs as well as elements of low flammability landscaping such as rock mulch and preferential vegetative selection for ornamental landscaped areas. Several homes represent exemplary Home Ignition Zones. The extent of choosing how to landscape, and management of the Home Ignition Zone is the responsibility of the individual landowner. Individual preferences can drive vegetation selection as there is no single landscape choice that is the only fire-resistant option. Fire mitigation is about taking an accumulation of choices by individual landowners to reduce risk at the community level. There are many ways to achieve the same management goal with a sliding scale of action and input driving results.
While there are still buildings made partially of non-fire-resistant materials, that does not mean that those individual residents are powerless to decrease potential damage or structure loss from wildfires. Neither does the presence of fire-resistant construction exclude the possibility of fire impact if the home ignition zone is not properly managed. Flammable items such as dead vegetation must be removed from the area immediately around the structure to prevent flames from contacting it. Also, reducing the volume of live vegetation and ladder fuels will affect the intensity of the wildfire as it enters the home ignition zone. To decrease the risk, flammable items should be thinned or removed from around the structure. Clearing vegetation in direct contact with the house will reduce the chance of flames physically connecting with the structure. Creating patches of fuel using isolated garden beds will cut down fire intensity by breaking up the continuous fuel leading up to the structure. Small groups of trees will be less likely to ignite leaving fire in the grass which gives off less radiant heat when it burns. If a group of trees were to ignite, having adequate distance between the groupings can reduce the threat of a larger crown fire moving through the tops of the neighboring trees. Reduction of ladder fuels, vegetation and other flammable vegetation that connect the tree canopies to the ground also helps with this. Some of these landscaping activities are currently active in the Davis Mountains Resort site.
Buildings do have openings to the interior of the structure, such as vents to an attic, dryer shoots, or vent access under the structure to allow air. These vents should be covered with a 1/8th inch screen. A 1/8th inch screen provides a reasonable amount of protection while not restricting air flow or requiring much upkeep to clean screens. A 1/16th inch screen provides better protection but at the drawback of more intensive maintenance requirements. The smaller screen size can lead to more common clogs and require cleaning more often to allow air flow. Screen is a cheap resource, and installation can be accomplished in a matter of hours on a weekend. This step is inexpensive, quick to install, and can significantly improve a structure’s chances of survival.
Beyond radiant heat and direct flame contact, ember wash is a considerable threat to the home. Embers are another characteristic of a wildfire that are not often considered by homeowners. Embers are small burning pieces of vegetation or wood that are carried by the wind ahead of a wildfire. An ember shower can be carried over a mile away from a wildfire and creates spot fires. When these embers land, depending on where that is, they can ignite vegetation on the roof, the gutters, the interior of the attic, or the garden beds around the house. These embers can be produced by a fire that is outside the boundaries of the community. Research in home ignitions through post fire assessments has shown that ember wash is the leading cause of structure loss in a wildfire.
Important Considerations
There is a herd of wild donkeys that reside within the resort that have been noted to help reduce fine fuels such as grasses and forbs, which are main carries of wildfire. However, there are areas where grasses are so sparse, assessors noted signs of erosion. While the largest direct cause of such stressors is unknown, the ambiguous population size of the herd should be considered. With local wildlife and donkeys present, the level of defoliation, especially in times of drought and low vegetation production rates should be closely monitored. Larger ecological impacts such as erosion, soil loss and degradation of the seedbed can happen rather quickly with long term detrimental effects as a result of improper stocking rates. In the future, the community could consider contacting a range specialist to calculate the carrying capacity of the Davis Mountains Resort to ensure that the herd size is appropriate and sustainable for the land to support without the need for residents to feed or care for the herd.
Wild donkeys in Davis Mountains Resort.
There are also several characteristics of the Davis Mountains Resort that residents are unable to change:
Site leadership should plan for and prepare for evacuations. With a single access point into a different subdivision, evacuations will likely be complicated. A pre-developed evacuation plan and regular drills will ensure that site planners and staff will be confident with the plan should the need for evacuations arise. Some helpful resources for this process are Ready, Set, Go (https://www.wildlandfirersg.org/) and the Texas A&M Forest Service Evacuation Resources webpage (https://tfsweb.tamu.edu/evacuationresources/). Another potential Davis Mountains Resort Risk Assessment www.facebook.com/wildfireeducation.prevention). All these resources have good videos and topics showing what needs to be in your evacuation kit and how to be aware of what evacuations may entail.
Next Steps
After reviewing the contents of this assessment and its recommendations, Davis Mountains Resort will determine whether to continue to seek Firewise, USA™ recognition. If the site assessment and recommendations are accepted and renewal is sought, Davis Mountains Resort will create an area-specific solution to the Firewise, USA™ recommendations and create an action plan in cooperation with the Texas A&M Forest Service.
To maintain national Firewise, USA™ recognitions status, DMR leadership it will integrate the following standards into its plan of action:
Additional Resources
For more information on the Home Ignition zone topic visit: https://tfsweb.tamu.edu/protectyourhome/
For an interactive, virtual course, register at https://nfpa.org/wildfirepreapredness for “Reducing Wildfire Risk to Property: Protecting Your Home or Business” a free, 1-hour session.
Kayla Driver Wildland Urban Interface Coordinator-San Angelo, TX325-304-4914