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HomeMy WebLinkAboutWildfire Mitigation Plan 04.2006WILDFIRE MITIGATION PLAN©
Elk Meadows LLC
Glenwood Springs, Colorado
April 2006
Prepared By:
ANCHOR POINT GROUP
3775 IRIS AVENUE, SUITE 2A, BOULDER, CO 80301 (303) 665 -FIRE
TABLE OF CONTENTS
EXECUTIVE SUMMARY 1
INTRODUCTION 2
Statement of Needs 2
Project Objectives 2
Background 2
Location 2
Regional History 3
Climate 4
FOREST MANAGEMENT AND WILDFIRE MITIGATION 5
Forest Management and Wildfire Mitigation Objectives 5
Current Risk Situation 5
Fire Regime and Condition Class 5
Condition Class Description 7
Fire Behavior Modeling 8
Fire Behavior Inputs 10
Fuel Models and Fire Behavior 13
FUEL MODEL 1 15
FUEL MODEL 2 17
FUEL MODEL 4 19
FUEL MODEL 6 21
FUEL MODEL 8 23
26
30
WILDFIRE MITIGATION RECOMMENDATIONS 31
Fire Behavior Outputs
Fire Behavior Interpretation and Limitations
ii
APPENDIXA -- PRESCRIBED BURNING ..A-1
APPENDIX B -- STRUCTURE PROTECTION FROM WILDFIRE B-1
APPENDIX C -- FIRE BEHAVIOR POTENTIAL ANALYSIS METHODOLOGY C-2
Purpose C-2
Model Description C-2
BEHAVE C-3
FlamMap C-3
APPENDIX D -- FIREWISE PLANT MATERIALS D-1
Quick Facts D-1
Fire Resistance D-1
Conifers D-2
Plants for a FireWise Landscape D-2
Additional FireWise Guidelines D-3
Don't Forget Maintenance D-3
Additional FireWise Publications D-4
Cooperative Extension D-4
Colorado State Forest Service D-4
FireWise Plant List D-5
Flowers and Ground Covers D-5
Shrubs D-8
Large Shrubs and Trees.. D-9
APPENDIX E -- CREATING WILDFIRE -DEFENSIBLE ZONES E-1
Quick Facts E-1
Defensible Space E-1
Defensible Space Management Zones E-2
Prescriptions E-3
Zone 1 .E-3
Zone 2 .. E-4
Zone 3 E-6
Special Recommendations E-7
Brush and shrubs E-7
Grasses E-8
Windthrow E-8
Maintaining Your Defensible Space E-8
Defensible Space and FireWise Annual Checklist E-9
References E-9
APPENDIX F -- FIRE-RESISTANT LANDSCAPING F-2
Quick Facts F-2
Landscaping Defensible Space F-2
Grasses F-4
Ground Cover Plants F-4
Wildflowers F-5
Shrubs F-5
Trees F-6
Structural Elements of a FireWise Landscape F-6
Maintenance F-7
References F-8
iv
Figure 1. Reserve at Elk Meadows at Glenwood Springs, Colorado
Regional History
The properties were settled in the 1880's and ranching became the main use. According to the
present owner, a large wildfire swept across the eastern area in the late 1800's or early 1900's.
By 1899, a railroad was constructed just west of Fourmile Road. It ran between Glenwood
Springs and Marion. A small spur called the Sunshine Spur ran west into the foothills near the
south property line. The railroad was abandoned in the 1930's and the tracks and trestles were
removed. The abutments for bridge crossings remain. A power line was constructed across the
southern portion of the upper Bershenyi property and was used along parts of its length as an
alternative route to the Bershenyi property; however, at several locations the grade in the right-
of-way is too steep for vehicles.
Timber and other wood products were removed on both properties for fences, fuel, and
construction. Cattle stocking appears to have been moderate depending on snow depth.
Livestock was moved between the Bershenyi properties depending on snow and range condition.
On the lower Bershenyi-Martino property, the gently sloping meadows of native grasses and
wildflowers were plowed up or interseeded with non-native plants. In the early 1990's the
meadow east of Fourmile Road and near the Martino residence was cultivated. The meadows
3
At-
were irrigated by ditches that captured spring snowmelt and periodic summer thunderstorm run-
off. The meadows were used for both hay production and pasture at different times.'
Climate
Garfield County has mountain climate, temperature and precipitation, which vary with altitude
and aspect. Higher elevations are typically cooler and receive more moisture; northern aspects
are cooler than southern aspects. Climatic data for the area are presented below.
Monthly Climate Summary for Glenwood Springs, Colorado
Period of Record: 1/2/1900 to 3/31/2005
GLENWOOD SPRINGS # 2, COLORADO (053359)
Average Max.
Temperature (F)
Average Min.
Temperature (F)
Average Total
Precipitation (in.)
Jan
Average Total Snow
Fall (in.)
Average Snow Depth
(in.)
36.9
11.7
rFeb
42.6
16.7
Mar
Apr
May
Jun
Jul
51.4
24.3
61.61
31.1
72.1
82.4
88.5
Aug
[Sep
Oct
86.1
78.4
38.2
1.27
1.41
1.64
1.44
18.2
5
11.4
3
6.5
0
1.9
0.3
0
44.0
0.0
50.6
r
1.26
[66.4
Nov
49.8
Dec
3 8.2
49.4
41.8
31.9
22.2
13.4
1.50
0.0
0.0
1.59
1.45
0.0
1.1
1.16
5.4
1.30
15.3
0
0
0
0
0
3
Annual
62.9
31.3
16.60
60.2
1
Table 1. Monthly Climate Summary for Glenwood Springs
Percent of possible observations for period of record.
Max. Temp.: 90.5% Min. Temp.: 90.3% Precipitation: 91.7% Snowfall: 87.7% Snow Depth: 41.6%
Retrieved on September 15th 2005 from http://www.wrcc.dri.edu/cgi-bin/ciiRECtM.pl?c:ogEen
1 Applied Ecological Services, (AES)
4
WILDFIRE MITIGATION
Wildfire Mitigation Objectives
1) Mitigate the risk of severe, uncontrollable wildfires by managing surface fuels and
enhancing open meadow areas.
2) Promote responsible development through FireWise Concepts.
3) Develop a holistic fire management package which includes:
a. Fuels Reduction
b. Construction Materials
c. Defensible Space
4) Minimize impacts to soils and the environment throughout the mitigation process.
Current Risk Situation
The majority of the study area is at moderate risk for wildland fires. The town of Glenwood
Springs is listed in the Federal Register as communities at high risk from wildfire (see
http://www.fireplan.govlreports/351-358-en.pdt). This cannot be directly extrapolated to the
Elk Meadows development, however many of the same parameters that arrive at a significant
risk are present. For the purposes of this report, the following definitions apply:
Risk is considered to be the likelihood of an ignition occurrence. This is primarily
determined by the fire history of the area.
Hazard is the combination of the wildfire hazard ratings of the WUI communities and fire
behavior potential, as modeled from the fuels, weather and topography of the study area. The
majority of the district is at a moderate risk for Wildland Urban Interface (WUI) fires.
Fire Regime and Condition Class
A system's historical range of variability provides a window for understanding the conditions
and processes that sustained ecosystems prior to significant human alteration. These reference
conditions serve as a guide for establishing future goals that will protect ecological systems and
meet societal objectives.3 Reference conditions serve as a guide for restoration of current
landscape conditions to improve ecological sustainability, and mitigate wildfire and post fire
erosion hazards.4
The fire -regime condition class (FRCC) is an expression of the departure of the current condition
from the historical fire regime. It is used as a proxy for the probability of severe fire effects
(e.g., the loss of key ecosystem components - soil, vegetation structure, species; or alteration of
2 Swanson et al. 1994.
3 Kaufmann et al. 1994, Kaufmann et al. 1998, Landres et al. 1999, Moore et al. 1999, Morgan et al. 1994.
4 Kaufmann et al. 2000a.
5
key ecosystem processes - nutrient cycles, hydrologic regimes). Consequently, FRCC is an index
of risk to the status of many components (e.g., water quality, fish status, wildlife habitats, etc.).
Figure 2 displays graphically the return interval and condition class of the study area.
Figure 2. Condition Classes Map
Condition Class N
Condition Class 1
; Condition Class 2
Condition Class 3
Agriculture & Non -Vegetative Areas
Elk Meadows Property Boundary
Deriving fire -regime condition class entails comparing current conditions to some estimate of the
historical range that existed prior to substantial settlement by Euro -Americans. The departure of
the current condition from the historical base line serves as a proxy to likely ecosystem effects.
In applying the condition class concept, we assume that historical fire regimes represent the
conditions under which the ecosystem components within fire -adapted ecosystems evolved and
have been maintained over time. Thus, if we project that fire intervals and/or fire severity has
changed from the historical conditions, we would expect that fire size, intensity, and burn
6
patterns would also be subsequently altered if a fire occurs. Furthermore, we assume that if these
basic fire characteristics have changed, then it is likely that there would be subsequent effects to
those ecosystem components that had adapted to the historical fire regimes. As used here, the
potential of ecosystem effects reflect the probability that key ecosystem components may be lost
should a fire occur. Furthermore, a key ecosystem component can represent virtually any
attribute of an ecosystem (for example, soil productivity, water quality, floral and faunal species,
large -diameter trees, snags, etc.). The following classes of condition are used to qualitatively
rank the potential of effects to key ecosystem components:
■ ,��p p
LIp I ` r
co
11,(' nni1din[1.' 7'r 1 1 I ti.nfulEEShii`K$ 1 R Cnrffllion -!rlli
II iia. HU.,," :. KC
s;T ; I f
,tiei {
-; 1 %, -
CIPMIt1GO1A t ass DearriiAim]
1
Fire regimes are within their historical range and the risk of losing key
ecosystem components as a result of wildfire is low. Vegetation
attributes (species composition and structure) are intact and functioning
within an historical range. Fire effects would be similar to those
expected during historical times.
2
Fire regimes have been moderately altered from their historical range.
The risk of losing key ecosystem components as a result of wildfire is ,
moderate. Fire frequencies have changed by one or more fire -return
intervals (either increased or decreased). Vegetation attributes have
been moderately altered from their historical range. Consequently,
wildfires would likely be larger, more intense, more severe, and have
altered burn patterns than that expected during historical times.
3
Fire regimes have changed substantially from their historical range.
The risk of losing key ecosystem components is high. Fire frequencies
have changed by two or more fire -return intervals. Vegetation
attributes have been significantly altered from their historical range.
Consequently, wildfires would likely be larger, more intense, more
severe, and have altered burn patterns than that expected during
historical times.
Table 2. Condition Class Descriptions
7
Together, reference conditions and current conditions are used to identify desired future
conditions, which are ecologically sustainable and congruent with desired land uses. Parameters
that require evaluation include vegetation density, fuel load, fire return interval, species
composition, landscape distribution, age distribution and habitat value. Monitoring and adaptive
management are necessary to ensure that goals are met. Adaptive management is a critical
component of ecological restoration because ecosystems are constantly changing in both time
and space.
The Glenwood Springs area has a significant fire history. Major fires in the area since 1994
include the Storm King Mountain fire, Coal Seam Fire, Black Mountain (West on I-70) and the
Center Mountain fire.
Fire Behavior Modeling
Fire behavior modeling provides a landscape level assessment of wildland fire hazards within the
project area. Potential fire behavior was analyzed in order to determine which areas are most
likely to burn and with what intensity.
A BEHAVE simulation was run to compute potential fire behavior characteristics over the entire
landscape for constant weather and moisture conditions. BEHAVE is a nationally recognized
methodology for estimating a fire's intensity and rate of spread given topography, fuels and
weather conditions. In order to model potential fire behavior across the project area, GIS data
layers including elevation, slope, aspect, fuel models and canopy closure were utilized in
FlamMap (see Figure 3). This modeling procedure yields three maps: 1) rate of spread, 2)
flame length and 3) crown fire activity. These output maps illustrate the potential for fire
behavior for the entire project area; they are used to prioritize treatment areas and guide fuel
treatments, which in turn reduce fire intensity. Two fire scenarios were modeled for the
property, one under moderate conditions and one under extreme conditions.
8
Figure 3. Fire Behavior Modeling
Elevation Slope
Aspect Canopy Cover Fuel Type
Canopy Bulk Canopy Base
Density Height
Local
Climate
Data
(R.A.W.S.)
Stand Height
Fire Behavior Analysis
Spread Rate Flame Length
Crown Fire
Activity
Images are not specific to this project
9
Fire Behavior Inputs
Fire behavior is dependant upon aspect, slope, elevation, canopy cover and fuel type.
Figure 4. Percent Slope
Pir >60
Elk Meadows Property Boundary
Parcel Boundaries/Future Roads
• •
M
0 1,000 2,000
Feet
Slopes are shown here as percent (rise/run x 100). Steeper slopes intensify fire behavior and thus
will contribute to a high wildfire hazard rating. Spread rate of a fire for a slope of 30% are
typically double those of flat terrain when all other influences are equal.
10
Figure 5. Aspect
Aspect
1111. North
West
- South
111111/ East
Elk Meadows Property Boundary
I Parcel Boundaries/Future Roads
0 1,000 2,000
Feet
Aspects are shown as degrees from North ranging from 0 to 360 according to their orientation.
Aspects are influential in the type and quantity of vegetative fuels. Fuels on south facing slopes
tend to be drier and more lightly loaded than fuels on north facing slopes when all other
influences are equal. Aspect also has an influence on species dominance.
11
Figure 6. Elevation
Elevation (ft)
MIL6,000
6,000 - 6,500
6,501 - 7,000
I1> 7,000
L__11 Elk Meadows Property Boundary
Parcel Boundaries/Future Roads
I}tl•
:'1!!4'R 17 I i t 1
lA 11
0 1,000 2,000
Feet
Elevations within the study area vary from approximately 6,000 feet to over 7,000 feet. As
elevation increases, fuel loading and species change. Above tree line, fuels become sparse and
the natural burn interval is measured in centuries.
12
Air
Fuel Models and Fire Behavior
Fuel models are a set of numbers that describe fuels in terms that a fire behavior model can use.
There are seven characteristics that are used to categorize fuel models.
• Fuel Loading
® Size and Shape
* Compactness
• Horizontal Continuity
• Vertical Arrangement
* Moisture Content
® Chemical Content
The study area is represented primarily by 5 fuel models (FM): FM 1, 2, 4, 6, and 8. Each of the
major fuel types present are described below with a table showing a range of surface fire
behavior based on the BEHAVE system. (See Appendix C for more information.) Figure 7
displays the fuel types graphically for the Elk Meadows development.
13
Figure 7. Elk Meadows Fuel Models
14
FUEL MODEL 1
Figure 8. Annual Grasses/Forbs
Characteristics
Grasslands and savanna are represented along with stubble, grass -tundra and grass -shrub
combinations.
Common Types/Species
Annual and perennial grasses are included in this fuel model.
Fire Behavior
Fire spread is governed by the fine, very porous and continuous herbaceous fuels that have cured
or are nearly cured. Fires in this fuel model are surface fires that move rapidly through the cured
grass and associated material. Very little shrub or timber is present, generally less than one-third
of the area.
15
Rate of s ' read in chains/hour 1 chain=66 ft
Mid -flame Wind Speed
28.8
22.0
19.4
16.7
11.0
92.9
71.1
62.4
53.9
35.6
203.6
155.7
136.8
118.1
64.8
362.4
277.0
243.4
198.7
64.8
570.1
345.1
270.1
198.7
64.8
665.6
345.1
270.1
198.7
64.8
10 hr fuel=5%, 100 hr fuel=6%, herbaceous fuel moisture=100%, slope=l0%
2.0
4.0
•
0.0
8.0
10.0
Flame Len th in Feet
Mid -flame Wind Speed
2.0 4.0
6.0 8.0
101) 12.0
3.0
2.4
2.2
2.0
1.4
5.1
4.]
3.8
3.4
2.4
7.3
5.9
5.5
4.9
3.2
9.6
7.8
7.1
6.3
3.2
11.8
8.6
7.5
6.3
3.2
12.7
8.6
7.5
6.3
3.2
10 hr fuel=5%, 100 hr fuel=6%, herbaceous fuel moisture=100%, slope=10%
16
LIST OF FIGURES
Figure 1. Reserve at Elk Meadows at Glenwood Springs, Colorado 3
Figure 2. Condition Classes Map 6
Figure 3. Fire Behavior Modeling 9
Figure 4. Percent Slope 10
Figure 5. Aspect 11
Figure 6. Elevation 12
Figure 7. Elk Meadows Fuel Models 14
Figure 8. Annual Grasses/Forbs 15
Figure 9. Sage and Grass Mix 17
Figure 10. Gambles Oak Over Four Feet Tall 19
Figure 11. Pinon Pine/Juniper Mix 21
Figure 12. Riparian Corridor, Cottonwoods 23
Figure 13. Rate of Spread Predictions (Average Weather Conditions) 26
Figure 14. Rate of Spread Predictions (Extreme Weather Conditions) 27
Figure 15. Flame Length Predictions (Average Weather Conditions) 28
Figure 16. Flame Length Predictions (Extreme Weather Conditions) 29
Figure 19. Fuel Breaks and Easements 33
Figure 20. Fire Behavior Flow chart 2
LIST OF TABLES
Table 1. Monthly Climate Summary for Glenwood Springs 4
Table 2. Condition Class Descriptions 7
Table 3. Reference Weather Used in the Fire Behavior Potential Evaluation 25
v
14.
EXECUTIVE SUMMARY
The Elk Meadows Wildfire Mitigation Plan has been created to meet initial and long range
development planning goals for the built environment and open space, to ensure ecosystem and
community sustainability and to integrate directives with social goals. Specific project goals
were to:
reduce the risk of catastrophic wildfire;
provide development options for the mitigation of wildfire, ensure compliance with local
fire district code requirements;
develop an integrated management approach that encompasses all natural communities
represented at Elk Meadows; and
provide a tool to help residents of Elk Meadows understand the complexity of the
ecosystem and more effectively protect their property from potential wildfires.
Vegetation management is needed throughout the upper montane zone of the Western Slope of
the Colorado Rocky Mountains to return forests and rangelands to an ecologically sustainable
condition and to reduce the potential for catastrophic wildfire and insect epidemics. Vegetative
conditions at the Elk Meadows property are significantly divergent from their historic norm. A
comprehensive evaluation of wildfire hazard within Elk Meadows was conducted; findings
should be integrated into the overall restoration prescriptions being developed for the property.
Project wide vegetation restoration treatments include the maintenance of meadows, strategic
fuel breaks to reduce vegetation density primarily through selective cutting to remove
undesirable species and retention of mature healthy plants, and implementation of prescribed
burning where feasible.
Other recommended actions include the utilization of ignition resistant construction for all homes
built in the development, in combination with individual defensible space. The authority having
jurisdiction, the Glenwood Springs Fire Department, dictates water supply requirements. Other
infrastructure recommendations are proposed to meet adopted code compliance.
The overall intent of this plan is to look, holistically, at the built and natural environments to
create a sustainable development that is in concert with sound ecological principles while
remaining fire resistant.
1
ma-
INTRODUCTION
Statement of Needs
The Elk Meadows Wildfire Mitigation Plan was created to meet medium and long-range
development planning goals, to mitigate the risk of wildfire, ensure that management activities
are ecologically sustainable, and to integrate these directives with social and development
preferences. This plan provides specific management direction to ensure the sustainability of the
development and serve as a management guide for open space.
Project Objectives
The three main objectives of the Elk Meadows Wildfire Mitigation Plan are to:
1) Provide a wildfire mitigation plan for development review and approval.
2) Help ensure the support of the Glenwood Fire Protection District.
3) Provide a tool for current and future residents of Elk Meadows to understand the
complexity of the Elk Meadows wildfire issue so that they can more effectively manage
their property in relation to this ecosystem.
Ack round
Location
The proposed Reserve at Elk Meadows at Glenwood Springs, Colorado, is approximately
1,659 acres in two separate areas. The general landscape is narrow plains, foothills, and low
montane (Figure 1). The eastern area contains a stream valley and slopes overlooking the
valley. The western area is a sloping plateau to the mountain ranges south and southwest.
The eastern area is reported to be 557 acres and consists of the Martino and lower Bershenyi
properties. It is roughly at 6,000 to 7,000 feet elevation and divided by the north -south running
Fourmile Road. A residence and ranch outbuildings are located near the road. Fourmile Creek
parallels and crosses Fourmile Road in the southeast of the property. The creek joins Roaring
Fork east of the property boundary.
2
FUEL MODEL 2
Figure 9. Sage and Grass Mix
Characteristics
Open shrub lands and pine stands or scrub oak stands that cover one-third to two-thirds of the
area may generally fit this model; such stands may include clumps of fuels that generate higher
intensities and that may produce firebrands. Scattered sage within grasslands and some pinyon -
juniper may be in this model.
Common Types/Species
Other tree and shrub species include common and Rocky Mountain juniper, buckbrush, sage,
bitter brush, and mountain mahogany. Mountain grasses are included in this model.
Fire Behavior
Fire spread is primarily through the fine herbaceous fuels, either curing or dead. These are
surface fires where the herbaceous material, in addition to litter and dead -down stem wood from
the open shrub or timber overstory, contribute to the fire intensity.
17
rt
Rate of s u read in chains/hour 1 chain=66 ft
Mid-Ilnnic Wind Speed
),O
1.0
6.0
8.0
12.0
12.4
10.2
9.0
8.3
7.4
34.2
28.0
24.9
22.9
20.5
67.5
55.3
49.1
45.3
40.5
111.6
91.4
81.2
74.9
67.0
166.0
135.9
120.8
111.3
99.7
230.2
188.5
167.6
154.4
138.3
10 hr fuel=5%, 100 hr fuel=6%, herbaceous fuel moisture=100%, slope=10%
Flame Len F th in Feet
Mid-17unic Wind Sherd
4.3
3.7
3.4
3.2
2.9
6.9
5.8
5.4
5.1
4.7
9.4
8.0
7.3
6.9
6.4
11.8
10.1
9.2
8.7
8.1
14.2
12.1
11.1
10.5
9.7
16.5
14.0
12.9
12.2
11.2
10 hr fuel=5%, 100 hr fuel=6%, herbaceous fuel moisture=100%, slope=10%
18
FUEL MODEL 4
Figure 10. Gambles Oak Over Four Feet Tall
Characteristics
This model consists of stands of small diameter trees or large shrubs with continuous closed
crowns. There may be high amounts of small dead limbs retained on the lower portion of trees.
There may also be high amounts of woody and needle litter associated with the stand.
Common Types/Species
Stands of mature shrubs, six or more feet tall, such as California mixed chaparral, and Scrub Oak
stands.
Fire Behavior
High rates of spread can be experienced in this model. Fire is carried through the foliage as well
as the fine live and dead woody material of tree crowns. Fire spread is also enhanced by the
amount of dead woody material on the ground.
19
" 1 ! ur:.i • I I., ,n„ „I
Rate of s read in chains/hour 1 chain=66 #t
2.0!
4.0
6.0
8.0
10.0
Mid -flame Wind Speed
30.4
27.0
24.8
23.5
22.6
21.7
70.6
62.6
57.5
54.4
52.3
50.2
120.4
106.8
98.1
92.8
89.2
85.8
177.9
157.7
145.0
137.1
131.8
126.7
241.8
214.4
197.0
186.3
179.1
172.2
311.3
276.0
253.7
239.9
230.6
221.7
10 hr fuel 5%, 100= 6%, woody fuel moisture= 100%, slope 10%
Flame Len ' th in Feet
2.0
4.0
6.0
8.0
10.0
12.0
13.9
12.6
11.7
11.2
10.9
10.6
20.5
18.5
17.2
16.5
16.0
15.6
26.2
23.6
22.0
21.1
20.5
19.9
31.3
28.3
26.4
25.2
24.5
23.8
36.1
32.6
30.4
29.1
28.3
27.4
40.5
36.6
34.1
32.7
31.7
30.8
10 hr fuel=5%, 100 hr fuel=6%, herbaceous fuel moisture=100%, slope=10%
20
FUEL MODEL 6
Figure 11. Pinon Pine/Juniper Mix
Characteristics
Shrubs in fuel model 6 are older than, but not as tall as, the shrub types of model 4. They also do
not contain as much fuel as model 4.
Common Types/Species
A broad range of shrub conditions is covered by this model. Pinyon juniper shrub lands may be
represented but may over -predict rate of spread except at high winds, such as 20 mi/h (32 km/h)
at the 20 -foot level.
Fire Behavior
Fires carry through the shrub layer where the foliage is more flammable, but this requires
moderate winds, greater than 8 mi/h (13 km/h), at mid -flame height. Fire will drop to the ground
at low wind speeds or at openings in the stand.
21
r"
Rate of s i read in chains/hour (1 chain=66 ft)
4.0
(.1)
8.0
10.1)
12.0
rergiiiimmuirrimpimingEggiumerwwr 2.0
17.2
13.9
11.7
10.2
9.2
8.5
38.5
31.1
26.2
22.9
20.7
19.1
63.9
51.7
43.5
38.1
34.4
31.7
92.4
74.8
62.9
55.0
49.7
45.9
123.5
99.9
84.1
73.6
66.5
61.4
156.8
126.9
106.8
93.4
84.4
77.9
10 hr fuel=5%, 100 hr fuel=6%, herbaceous fuel moisture=100%, slope=lO%,
Flame Length in Feet
Mid-Ilaiiic Wind Sliced
2.0
4.0
6.1)
8.0
10.0
12.
5.0
4.3
3.8
3.4
3.2
3.1
7.3
6.2
5.5
5.0
4.7
4.4
9.2
7.8
6.9
6.3
5.9
5.6
10.9
9.3
8.2
7.4
7.0
6.7
12.4
10.6
9.3
8.5
8.0
7.6
13.9
11.8
10.4
9.5
8.9
8.5
10 hr fuel=5%, 100 hr fuel=6%, herbaceous fuel moisture=100%, slope -10%, wind
direction=upslope
22
FUEL MODEL 8
Figure 12. Riparian Corridor, Cottonwoods
Characteristics
Hardwoods that have leafed out support fire in the compact litter layer. This layer is mainly
needles, leaves, and occasionally twigs because little undergrowth is present in the stand.
Amounts of needle and woody litter are also low.
Common Types/Species
Plains Cottonwood and several species of willows along riparian areas are represented here.
There are mostly streamside understory plants that do not contribute to the fire intensity.
Fire Behavior
Fires in this fuel model are slow burning, low intensity fires burning in surface fuels. Fuels are
mainly needles and woody litter. Heavier fuel loadings from old dead and down trees or branches
can cause flare-ups. Heavier fuel loads have the potential to develop crown fires in extreme
burning conditions.
23
.r -
Rate of spread in chains/hour (1 chain=66 ft)
1.1
0.9
0.7
0.6
0.6
0.5
2.3
1.9
1.6
1.4
1.2
1.1
3.9
3.2
2.6
2.3
2.0
1.8
5.7
4.7
3.9
3.4
3.0
2.7
7.8
6.4
4.9
3.8
3.1
2.7
10.1
6.9
4.9
3.8
3.1
2.7
10 hr fuel=5%, 100 hr fuel=6%, herbaceous fuel moisture=100%, slope=l0%
-•
r,
4.0
6.0
8.0
10.0
Flame Len th in Feet
Mid -flame Wind Speed
6.0 ' `
10.0...
0.9
0.8
0.7
0.6
0.6
0.6
1.3
1.1
1.0
0.9
0.8
0.8
1.7
1.4
1.2
1.1
1.0
1.0
2.0
1.7
1.5
1.3
1.2
1.2
2.3
2.0
1.7
1.4
1.3
1.3
2.6
2.0
1.7
1.4
1.3
1.3
10 hr fuel=5%, 100 hr fuel=6%, herbaceous fuel moisture=100%, slope=l0%
24
The weather inputs for FlamMap were created by using weather data collected at Rifle Remote
Automated Weather Station (RAWS). It was determined that this RAWS site provided the best
option for weather data for the project area.
Latitude (dd mm ss)
39 ° 30'
51 " N
Longitude (dd mm ss)
107 °
45
' 26 " W
Elevation (ft.)
6120
4
10 hr fuel moisture
Table 3. Reference Weather Used in the Fire Behavior Potential Evaluation
Weather observations from the Rifle (RAWS) were averaged for a ten-year period (May to
October 1984-2005) to calculate these conditions. The average conditions class (16t to 89th
percentile) was calculated for each variable (1 hour, 10 hour, and 100 hour fuel moisture, woody
fuel moisture, herbaceous fuel moisture, and wind speed) using Fire Family Plus. This weather
condition class most closely represents an average fire season day.
The extreme conditions class was calculated using ninety-seventh percentile weather data. That
is to say, the weather conditions existing on the four most severe fire weather days (sorted by
Spread Component) in each season for the ten-year period were averaged together. It is
reasonable to assume that similar conditions may exist for at least four days of the fire season
during an average year. In fact, during extreme years such as 2000 and 2002, such conditions
may exist for significantly longer periods. Even these calculations may be conservative
compared to observed fire behavior. The following values were used in FlamMap:
Average Weather Conditions
Variable
Value
20 ft Wind speed up f 6
slope r
Herbaceous fuel
moisture
30
Woody fuel moisture
72
100 hr fuel moisture
4
10 hr fuel moisture
5
1 hr fuel moisture
8
Extreme Weather Conditions
'Mika riabi
Value
20 ft Wind speed up
slope
21
Herbaceous fuel
moisture
30
Woody fuel moisture
66
100 hr fuel moisture
2
10 hr fuel moisture
3
1 hr fuel moisture
6
25
Fire Behavior Outputs
From the fire behavior analysis predictions of rate of spread and flame length are derived. The
maps graphically display the outputs of FlamMap for both average and extreme weather
conditions.
Figure 13. Rate of Spread Predictions (Average Weather Conditions)
[—Spread Rate (chains/hr)
N/A
1 0.1 - 20.0
20.1 - 40.0 (Not Present on Map)
40.1 - 60.0 (Not Present on Map)
11111 >60.0
F-7 Elk Meadows Property Boundary
Parcel Boundaries/Future Roads
, V
N
0 1,000 2,000
=1 Feet
26
Figure 14. Rate of Spread Predictions (Extreme Weather Conditions)
Spread Rate (chains/hr)
IN/A
I0.1 - 20.0
20.1 - 40.0 (Not Present on Map)
MI40.1 - 60.0 (Not Present on Map)
>60.0
1 _ Elk Meadows Property Boundary
Parcel Boundaries/Future Roads
0 1,000 2,000
Feet
Spread rate values are generated by the FlamMap model and classified into four categories
based on standard ranges: 0-20 CPH (chains/hour), 20.1-40 CPH, 40.1-60 CPH, and greater than
60 CPH. A chain is a logging measurement that is equal to 66 feet. One mile equals 80 chains.
1 CPH equals approximately 1 foot/minute.
27
Figure 15. Flame Length Predictions (Average Weather Conditions)
Flame Length (ft)
1 N/A
10.1 - 4.0
4.1 - 8.0
8.1 - 12.0
> 12.0
Elk Meadows Property Boundary
Parcel Boundaries/Future Roads
0 1,000 2,000
Feet
28
Figure 16. Flame Length Predictions (Extreme Weather Conditions)
Flame Length (ft)
IN/A
n0.1 - 4.0
4.1 - 8.0 (Not Present on Map)
I8.1 - 12.0
-12.0
17IElk Meadows Property Boundary
Parcel Boundaries/Future Roads
A
0 1,000 2,000
Feet
Flame length values are generated by the FlamMap model and classified in the four categories
based on standard ranges: 0-4 feet, 4.1-8 feet, 8.1-12 feet and 12.1-60 feet. Flame lengths of
4 feet and less are acceptable for direct attack by hand crews. Flame lengths of 8 feet and less are
suitable for direct attack by machinery. With flame lengths of greater than 8 feet, indirect and
aerial attacks are the preferred methods.
29
Fire Behavior Interpretation and Limitations
This area is dominated by shrubs and grass. The most significant factor in fire behavior for this
type of fuel is wind. Under extreme conditions, all the fuel models burn with very high intensity
and great speed. In order for fire to move through the area, it needs continuous fuels. In years
with good moisture, a higher fuel load of grass can be expected and, as they cure, can become a
problem later in the season. On dry years, or during drought conditions, the grass will be very
sparse and there will be mostly bare ground between the shrubs.
Shrubs can appear green and still burn very well due to volatile oils in the leaves and bark.
Shrubs will also have dead wood that may not be seen due to the leaf canopy. Because most of
the shrubs lose their leaves in the fall, the threat for late fall and winter fires is very low. If there
is good moisture in the spring, the shrubs will not burn until much later in the summer.
Gambles Oak is especially dangerous as it has a waxy coating on the leaves that helps it burn
intensely under the proper conditions. The dense stands to the west of the development pose the
greatest threat from wildfire. Fortunately, most of these stands are upslope and would likely
burn up hill and away from the area. The rate of spread under moderate conditions is quite fast,
almost 1 mph and under extreme conditions 2-4 mph, and would be common along with
spotting. The flamelengths in the oak would be too intense for direct attack from hand crews.
The steeper slopes would also contribute to the intensity.
Sage varies in its burning intensity by the age and structure of the plants. Areas that are actively
browsed will typically be very low growing, have new growth and burn less intensely. As the
plant gets older and/or not browsed, it will become decadent with much of the plant dying off
and contributing to more intense burning. Under moderate conditions, the fire could be fought
by direct attack methods safely. Under extreme conditions, it would move very fast and move
through the crown of the plants, creating spotting problems.
Pinyon/Juniper stands typically burn only with strong winds. The spacing is usually enough that
the fire cannot spread from tree to tree unless the wind is pushing it. As soon as the wind stops,
the fire will drop to the ground and smolder due to the lack of fuel on the ground. Under
moderate conditions, it is very similar to the sage and probably even less likely to burn. Under
extreme conditions, fires can move quickly and become crown fires that are very difficult to
extinguish.
The Cottonwoods and Willows do not pose much threat from wildfire. They would most likely
be a barrier and help to stop fire due to the typically wet conditions in the area. Even if the
stream is dry, there is not a significant fuel to carry the fire. It would be a good idea to clean up
the stream corridor to prevent fuels from building up during high flows, which could possibly
make heavy fuel loads of dead and down material.
30
Wei
}
Wildfire Mitigation Recommendations
In response to the comprehensive analysis described above, the following elements for creating a
FireWise development are suggested.
Municipal water supply for fire suppression as per 2000 Urban —Wildland Interface Code
1,000 Gal/ min for 30 Min duration for structures having a fire area, which does not
exceed 3600 sq. feet (30,000 gal.)
1,500 Gal/ min for 30 Min duration for structures having a fire area, which does
exceed 3600 sq. feet (45,000 gal.)
> A reduction in required flow rate of 50% when the building is provided with an
approved automatic sprinkler system
> Structures will provide an exterior FDC
Delivery method provided by strategically placed municipal hydrants with minimum PSI
and volumes meeting UWIC requirements.
Roads, streets and ways will follow 2000 UWIC Chapter 4 Section 403
Defeo (,trpRe
All homes and common buildings will be required to develop and maintain defensible space.
Defensible space includes the
use of FireWise Vegetative
management that removes
flammable fuels from around a
structure to reduce exposure to
radiant heat. The flammable
fuels may be replaced with
green lawn, gardens, certain
individually spaced green,
ornamental shrubs,
individually spaced and
pruned trees, decorative stone
or other non-flammable or
flame -resistant materials.
Although this diagram depicts defensible space in relation to trees, the same zonal approach
and general thinning standards still apply. FireWise plant materials are listed in Appendix D.
Defensible space should be created in concert with the homeowner and builder's design
aesthetic to create both a pleasing look and fire resistant landscape.
Defensible Space
Lovn' 2 1o1ir 3
Segf left
` Mssdury ve411
Pi1i+
Hammy paha
Landctaped are��
only 1.olnted [reel
1r is ham adequnp
feltaratlimv & am
limbed to 8'
irces Aft p.vnW
o! dead matuial.
1
31
ignition IZ,°�istant onstriicti '
Class A roof coverings required for all structures
Fuels Reduction
• All lots will have a Defensible Space Easement (Figure 17) platted and accepted in
covenants. This area will allow homeowners to extend and maintain their defensible
space beyond their property line if an extended distance is required. This area will be
covenant restricted to any dumping or disposal of combustible materials or yard waste.
Fuel Breaks
Fuel Breaks
Three fuel breaks will be provided for the development (see Figure 17). The intent of
the fuel breaks is to reduce the intensity and rate of spread of the fire. The fuel breaks
are located in areas where fire behavior can be most affected by topography or prevailing
winds. These areas should be delineated as Fuels Reduction Easements on the final plat
map and in the development's covenants. On-site evaluation will determine if
mechanical treatment is necessary or if an extended defensible space with selective plant
removal is most appropriate. These fuel break areas would be maintained in addition to
each individual defensible space around homes. All of the fuel breaks leverage off of the
proposed trail system. Fuel breaks 2 and 3 follow the system, significantly, while the
northern fuel break (1) utilizes the trail parking area and the road as an anchor point
before continuing southward around the development. The intent is to utilize the trail
system as the centerline for the fuels breaks, minimizing site disturbance while
enhancing fuelbreak maintenance and function. Specific, on the ground, layout of the
fuels breaks will be necessary and may deviate from the trails as warranted.
32
s
Figure 17. Fuel Breaks and Easements
Fuelbreaks
2
3
LJElk Meadows Property Boundary
Parcel Boundaries/Future Roads
Fuelbreak Easements
o 1.000 2,000
• Feet
4t'
A
•
• •
'':r.Ar-4..*•.,t4b
. •
it*
33
I, II ir WWI 1.,„
(i PHI
Justification
It is the recommendation of this report that these elements be selected by the authority having
jurisdiction as the best approach for new development in this area. In the Wildland Urban
Interface (WUI), water supply is not the overriding mitigation element for fire suppression and
property conservation. These recomendations provide the best balance between the critical
elements of water, access, fuels reduction and ignition resistant construction.
To mitigate the potential for a structure fire extending beyond the building into the wildland and
creating a significant event, residential 13D sprinkler systems with the appropriate volume and
fire flow for each specific structure are required. An additional element, beyond residential code
requirements, is the addition of an exterior fire department connection (FDC). This allows
incoming engines to utilize tank water to augment the on-site 13-D system. Additionally
municipal pressurized hydrants are to be placed strategically, and augmented with water tender
shuttles or relay pumping to areas greater than 1,000' of the hydrants.
If a 13-D system should be disabled or fail and a breach of the structure should occur, defensible
space as a fuels reduction technique, to limit fire spread from the structure to the surrounding
vegetation, will be installed. A Defensible Space Easement will be established to ensure that the
proper defensible space distances are met even beyond individual properly lines.
Additionally class "A" roof covering will be required. This provides protection, for the most
critical area of the house, from ember generation in the event of a wildland fire.
From a wildfire perspective, a spectrum of solutions for the development are offered. Including
geographic fuel breaks adjacent to neighborhoods and structures to reduce the rate of spread and
intensity of an encroaching wildfire. Fuel breaks in combination with defensible space are the
best solution to keep direct radiant heat and flame contact from igniting structures.
The water supply configuration is sufficient for structure protection and wildfire suppression. In
most jurisdictions throughout the United States, it is taught and recommended that engines do
not hook up to water sources other than to fill their tanks. Mobility is the key to fire suppression
in the wildland urban interface. Ample fill sites (pressurized hydrants) will be available.
Access standards will adhere to the 2000 UWIC. This code specifies reasonable and practical
access standards for the UWI, not the overly restrictive requirements of the Uniform Fire Code
(UFC) which were developed for an urban application. Often meeting UFC standards for access
in rural areas creates unnecessary and undesirable resource damage. The UWIC access
standards are sufficient for fire department access and egress while balancing the need for
responsible land development.
For these reasons, this report recommends the above stated elements be utilized to provide the
most efficient and effective approach for responsible development for the Elk Meadows Project.
34
Appendix A
Prescribed Burning
Prescribed burns are generally the most effective means of reducing fire hazard, eliminating
large numbers of understory trees, stimulating seral herbaceous and shrubby vegetation, creating
receptive seedbeds and transforming nutrients into an available forms. Prescribed burns are
known to mitigate wildfire effects6 and can create landscape diversity that would be impossible
to replicate by mechanical means alone. The structural diversity created by fire is also the best
way to integrate management for varied ecological communities: there is no ecological substitute
for burning. Many forest conditions, however, preclude the implementation of fire without
mechanical treatments prior to prescription burns. A management scheme incorporating both
mechanical thinning and prescribed fire is therefore most likely to succeed.
The success of mechanical treatments
used in conjunction with prescribed burns
is illustrated by the Eldorado Fire in
Boulder County (left). The background of
this photo (green circle) received both
thinning and prescribed fire in the fall of
1998 while the foreground (orange circle)
received no treatment. A wildfire burned
through both areas in September 2000; a
stand replacing "catastrophic" fire
occurred in the orange circle while a low
intensity surface fire occurred in the
background (green circle).
The Elk Meadows development is quite suitable for prescribed burning. The fire would help
reduce decadent stands of shrubs and would stimulate new growth that will be much more
resistant to fire. The grass meadows would benefit greatly by removing thatch and weeds, and
put nutrients back into the soil. In combination with mechanical treatments, it will help restore a
healthier ecosystem that will be easier to maintain.
Prescribed burning is a potentially risky and dangerous operation; it should only be implemented
by professionally trained and certified personnel.
5 Arno and Harrington 1995, Fiedler et al. 1995
6 Wagle and Eakle 1979
A-1
Appendix B
Structure Protection from Wildfire
Construction in Elk Meadows should be required to follow Ignition Resistant Constructing
Class I standards as defined in the ICC Wildland Urban Interface Code. These construction
techniques, in combination with fuels reduction on both the landscape and home -site level,
should create a condition where developed property would have a low -to -moderate impact from
a moderate intensity wildfire. Additionally, other improvements could be made to further ensure
protection from fire. Some of these elements are detailed in these fact sheets from the Colorado
State Forest Service:
http://www.ext.colostate.edu/pubs/natres/06302.1itml
6.302, Creating Wildfire -Defensible Zones;
6.303, Fire -Resistant Landscaping;
6.305, FireWise Plant Materials; and
6.306, Grass Seed Mixes to Reduce Wildfire Hazard.
Below is a maintenance checklist. Do not wait until a fire is approaching to perform
these tasks. These should be done as conditions dictate, several times a year.
LJ Thin tree and brush cover
❑ Dispose of slash and debris left from thinning
❑ Remove dead limbs and other litter
LI Maintain an irrigated greenbelt if possible, mow dry grasses and weeds regularly
around structures out to 30 feet
IJ Rake debris away from corners and culverts where they may accumulate
l,] Prune branches 8 to 10 feet above the ground
❑ Reduce forest density surrounding structures, beyond the established defensible
space
Li Keep flammable materials away from vegetation
B-1
zalC ■
Appendix C
Fire Behavior Potential Analysis Methodology
Purpose
The purpose of this appendix is to describe the methodology used to evaluate the threat
represented by physical hazards, such as fuels, weather and topography, to values -at -risk in the
study area by modeling their effects on fire behavior potential.
Model Description
Figure 18. Fire Behavior Flow chart
Elevation Slope
Aspeot
Canopy Cover Fuel Type
Canopy Bulk Canopy Base
Density Height
w
Local
Climate
Data
(R.A.W.S.)
Stand Haight
Fire Behavior Analysis ,
Spread Rate
Flame Length
Crown Fire
Activity
The fire behavior potential analysis represents a relative ranking of locations based upon fire
behavior predicted by the model. The model inputs include aspect, slope, elevation, canopy
cover, fuel type, canopy bulk density, canopy base height and stand height. The model outputs
C-2
are determined using FlamMap7 which combines surface fire predictions with the potential for
crown fire development. Calculations for surface fire predictions (rate of spread and flame
length) are based on the USDA Forest Service's BEHAVES model.
BEHAVE
The BEHAVE fire behavior prediction and fuel modeling system was utilized to determine surface
fire behavior estimates for this study. BEHAVE is a nationally recognized set of calculations used
to estimate a surface fire's intensity and rate of spread given certain conditions of topography,
fuels and weather. The BEHAVE modeling system has been used for a variety of applications
including prediction of an ongoing fire, prescribed fire planning, fuel hazard assessment, initial
attack dispatch and fire prevention planning and training. Predictions of wildland fire behavior are
made for a single point in time and space given simple user -defined fuels, weather and topography.
Requested values depend on the modeling choices made by the user.
Assumptions of BEHAVE:
Fire is predicted at the flaming front
Fire is free burning
Behavior is heavily weighted towards the fine fuels
Continuous and uniform fuels
Surface fires
FlamMap
Anchor Point uses FlamMap to evaluate the potential fire conditions in the study area. The Elk
Meadows study area encompasses approximately 557 acres (0.87 square miles). This area,
which includes the development and a buffer of approximately 100 meters in all directions, is
broken down into 10 meter (M) grids. Using existing vector and raster spatial data and field data,
ArcGIS spatial analysis capabilities are utilized to calculate model inputs for each 10 meter
square (MSq) grid. These values are input into FlamMap, along with reference weather and fuel
moisture (long-term weather observations statistically calculated from the Pickle Gulch Remote
Automated Weather Station information). The outputs of FlamMap include the estimated Rate
of Spread (ROS) (from BEHAVE), Flame Length (FL) (from BEHAVE) and Crown Fire
Activity for a fire in that*+ -10 MSq grid. The model computes these values for each grid cell in
the study area.
7 Mark Finney, Stuart Brittain and Rob Seli., The Joint Fire Sciences Program of the Rocky Mountain Research
Station (USDA Forest Service, Missoula, Montana), the Bureau of Land Management and Systems for
Environmental Management (Missoula, Montana).
8 Patricia L. Andrews, producer and designer, Collin D. Bevins, programmer and designer., The Joint Fire Sciences
Program of the Rocky Mountain Research Station (USDA Forest Service, Missoula, Montana) and Systems for
Environmental Management (Missoula, Montana).
C-3
3.
1
This evaluation is a prediction of likely fire behavior given a standardized set of conditions and a
single point source ignition at every point. It does not consider cumulative impacts of increased
fire intensity over time and space. The model does not calculate the probability that a wildfire
will occur. It assumes an ignition occurrence for every cell (a 10 x 10 meter area).
Weather conditions are extremely variable and not all combinations are accounted for. These
outputs are best used for pre -planning and not as a stand-alone product for tactical planning. It is
recommended that whenever possible, fire behavior calculations be done with actual weather
observations during the fire. It is also recommended that the most current ERC values be
calculated and distributed during the fire season to be used as a guideline for fire behavior
potential.
C-4
Appendix D
Fire Wise Plant Materials
F.C. Dennis9 -- no. 6.305
Quick Facts
FireWise landscaping can be aesthetically pleasing while reducing potential wildfire fuel.
Plant choice, spacing and maintenance are critical.
Your landscape, and the plants in it, must be maintained to retain their FireWise
properties.
Creating a "defensible space" around your home is one of the most important and effective steps
you can take to protect you, your family and your home from catastrophic wildfire. Defensible
space is the area between a structure and an oncoming wildfire where nearby vegetation has been
modified to reduce a wildfire's intensity. (See fact sheet 6.302, Creating Wildfire -Defensible
Zones.)
Many people resist creating defensible space around their homes because they believe these
areas will be unattractive and unnatural. This is far from true. With careful planning, FireWise
landscaping can be aesthetically pleasing while reducing potential wildfire fuel. It can actually
enhance beauty and property values, as well as personal safety.
Fire Resistance
Many native plants are highly flammable during different seasons of the year. At such times, left
unmanaged, they can accelerate the spread of a wildfire through your neighborhood, threatening
homes, property and lives.
All vegetation, naturally occurring and otherwise, is potential fuel for fire. Its type, amount and
arrangement has a dramatic effect on fire behavior. There are no truly "fireproof' plant species,
so plant choice, spacing and maintenance are critical to defensible space landscaping. In fact,
where and how you plant may be more important than what you plant. However, given
alternatives, choose plant species that tend to be more resistant to wildfire.
9 Wildfire Hazard Mitigation Coordinator, Colorado State Forest Service. 10/99. Reviewed 1/06.
D-1
General concepts to keep in mind when choosing and planting FireWise species are:
A plant's moisture content is the single most important factor governing its volatility.
(However, resin content and other factors in some species render them flammable even
when the plant is well -watered.) Conifers tend to be flammable due to their oil and pitch
content, regardless of their water content.
Deciduous plants tend to be more fire resistant because their leaves have higher moisture
content and their basic chemistry is less flammable. Also, when deciduous trees are
dormant, there is less fuel to carry fire through their canopies.
In some cases, there is a strong correlation between drought tolerance and fire resistance. For
example, a plant may shed its leaves or needles during extreme drought. Other drought -tolerant
species may have smaller leaves or thick, succulent leaves. These plants offer less fuel or have a
higher moisture content, both of which help reduce fire hazard.
There also appears to be a correlation between a plant's salt tolerance and natural fire resistance.
Plants adapted to salty conditions, and actually growing in salty situations, may better resist
burning.
Conifers
In Colorado, conifers make up much of our natural forest. Because of their high resin content,
they are more susceptible to fire.
Even though conifers are flammable, you do not need to remove all of them from around your
home. Wildfire hazards usually can be effectively reduced through proper thinning and pruning
of existing trees and shrubs.
When choosing conifers for your defensible space, consider those with characteristics that make
them better able to survive fire:
thick bark,
long needles, or
self -pruning. (Self -pruning trees lose lower branches naturally, leaving a greater distance
between ground and canopy.)
Plants for a FireWise Landscape
Plants that are more resistant to wildfire have one or more of the following characteristics:
They grow without accumulating large amounts of combustible dead branches, needles or
leaves (example: aspen).
4, They have open, loose branches with a low volume of total vegetation (examples: currant
and mountain mahogany).
They have low sap or resin content (examples: many deciduous species).
They have high moisture content (examples: succulents and some herbaceous species).
D-2
They grow slowly and need little maintenance (do not need frequent pruning).
They are short and grow close to the ground (examples: wildflowers and groundcovers).
They can resprout following fire, thus reducing relandscaping costs (example: aspen).
Additional FireWise Guidelines
Some additional tips to follow when planning a FireWise landscape include:
fo
Landscape according to the recommended defensible -space zones. The plants nearest
your home should be more widely spaced and smaller than those farther away.
Plant in small, irregular clusters and islands, not in large masses.
Break up the continuity of the vegetation (fuel) with decorative rock, gravel and stepping
stone pathways. This will help modify fire behavior and slow its spread across your
property.
Plant a variety of types and species. Besides being aesthetically pleasing, this will help
ensure a healthier forest by reducing Insects and diseases. Healthy, vigorous, thinned
forests can better resist catastrophic fires than unhealthy ones with insect and disease
problems.
In the event of drought and water rationing, prioritize the plants you wish to save.
Provide supplemental water to those nearest your home, perhaps using "gray water."
Mulch to conserve moisture and reduce weed growth. Mulch can be organic (wood chips
or small bark pieces) or inorganic (gravel or rock). Avoid pine bark, thick layers of pine
needles or other materials that can easily carry fire.
Don't Forget Maintenance
A landscape is a dynamic, constantly changing system. Plants considered "fire resistant" and that
have low fuel volumes can lose these characteristics over time. Your landscape, and the plants in
it, must be maintained to retain their FireWise properties.
Be aware of the growth habits of the plants on your land and of the changes that occur
seasonally. Keep a watchful eye for the need to reduce fuel volumes and fuel continuity.
Remove annual, herbaceous plants after they have gone to seed or when the stems
become overly dry.
Rake up and dispose of litter as it builds up over the season.
Mow or trim grasses to a low height within your defensible space. This is especially
important as they begin to cure and dry.
Remove plant parts damaged by snow, wind, frost or other agents.
Timely pruning is critical. It not only reduces fuel volume but also maintains healthier
plants with more succulent, vigorous growth.
D-3
Additional FireWise Publications
(Cooperative 1 'tension
The following publications are available from The Other Bookstore, Colorado State University
Cooperative Extension, 115 General Services Bldg., Fort Collins, CO 80523-4061; (970) 491-
6198; resourcecenter@ucm.colostate.edu. Printed copies cost $1; they are available free on our
Web site at www.cerc.colostate.edu:
6.302, Creating Wildfire -Defensible Zones
6.303, Fire -Resistant Landscaping
6.304. Fire Safety, Evacuation and Horne Defense
6.306, Grass Seed Mixes for the Reduction of Wildfire Hazard
7.205, Pruning Evergreens
7.206, Pruning Shrubs
7.207, Pruning Deciduous Trees
7.402, Protecting Trees During Construction
Colorado State Forest ServiPe
The following publication is available from the Colorado State Forest Service, Colorado State
University, Fort Collins, CO 80523-5060; (970) 491-6303:
Home Fire Protection in the Wildland Urban Interface, CSFS #142-399
D-4
FireWise Plant List
The following list was prepared by Phil Hoefer, Colorado State Forest Service. It was reviewed
by Jim Knopf, a landscape architect in Boulder, and two landscape architects on Colorado's
Western Slope. Bloom time is approximate (observed in Boulder at 5,600 feet).
Key: Water needs:
Sun/Shade:
'Elevation:
Scientific Name
Achillea lanulosaa
Achillea tomentosab
Aconitum spp.6
Aconitum
columbianuma°
,Ajuga reptansb
Alchemilla sp.
;Allium cernuuma°
Allium geyeriaa
;Anaphalis
,margaritaceaa
Anemone blanda
Antennaria
parvifoliaab
;Antennaria roseaab
,Aquilegia spp.
Aquilegia coeruleaa
;Aquilegia chrysanthaa
Arab's
sp.b
;Armenia maritima
Artemisia caucasica
!Artemisia frigidaac
VL = very low
S = sun
Y=Yes
`L = low
'PS =part sun
N=No
= medium
`Sh = shade
= Questionable or unknown
= high
Approx. Sun/ Approx. Elevation Approx.
Common Name Water Shade Mature (1,000 ft.) Bloom
Needs Preference Height5 6 7 8 9 Month
Flowers and Ground Covers
"Native yarrow
Woolly yarrow
Monkshood
'Columbian monkshood
Bugleweed
Ladys mantle
;Nodding onion
'Geyer onion
'Pearly everlasting
Windflower
Small -leaf pussytoes
;Rosy pussytoes
Columbine
'Colorado blue columbine
'Yellow columbine
Rockcress
Sea thrift
'Caucasian sage
"Fringed sage
L -H S/PS
M -H S/PS
M -H S
M -H S
H Sh
M -H PS/Sh
L -H S/PS
L -H S/PS
L -H S
M -H S/PS
M S/PS
M S/PS
M -H S/PS
M -H S/PS
M -H S/PS
L -H S
L -H S/PS
L -M S/PS
L -M S
1.5-2' Y'Y'Y Y Y Jul
.5' YY NNN Jul
2' Y'Y'Y Y Y Jun -Jul
2' Y Y Y YY Jun -Jul
<.5' YY'Y Y Y Jun -Jul
1' Y Y Y Y ? Jun -Jul
1' Y'YYYY Jun
1' YYYY ? Jun
1.5-2.5' Y Y Y Y ? Aug
1' Y Y Y `Y ? Apr -May
<.5' Y'Y'Y Y Y Jun
<.5' 'Y'Y'Y 'Y'Y Jun
1 - 2' •Y ' Y ' Y ' Y ' Y Jun -Jul
1 - 2' 'Y'Y'Y'Y 'Y Jun -Jul
1 - 2' 'Y 'Y Y'Y'Y Jun -Aug
< 1' Y Y' Y Y Y May -Jun
.5' 'Y 'Y 'Y 'Y'Y Apr -Jun
1-2' 1Y'Y Y ? ? n/a
1-1.5' 'Y'Y Y Y Y n/a
D-5
Artemisia
ludovicianaa
Aster laevisa
Aster porteria
,Aubrieta sp.b
Aurinia sp.b
Calochortus
gunnisoni
;Campanula
rotundifoliaa
;Centranthus ruber
-Cerastium strictumt
`Cerastium
tomentosumb
Claytonia lanceolataa
!Prairie sage
Smooth aster
Porter aster
;False rockcress
;Basket of gold
;Mariposa lily
Common harebell
;Jupiters beard
;Mouse ear chickweed
i Snow -in -summer
Spring beauty
Convallaria majalisb° ;Lily-of--the-valley
Delosperma
nubigenumb
Delphinium spp.`
Dianthus spp.
Doronicum sp.
Echinacea purpurea
Epilobium
angustifolium
Erigeron flagellarisa
Eriogonum
umbellatuma
Erysimum asperuma
Gaillardia aristataa
:Galium borealeab
Geranium spp.
Geranium
caespitosuma
Geum triflorum
;Helianthella
':,quinquenervisa
`Hardy yellow iceplant
;Delphinium
Pinks
;Leopards bane
;Purple coneflower
:Fireweed
Whiplash daisy, trailing
ifleabane
Sulphur flower
'Western wallflower
;Blanket flower
Northern bedstraw
;Hardy geraniums
Wild geranium
!Prairie smoke
;Aspen sunflower
L -M S 1- 1.5' Y Y Y? ? n/a
L -H S/PS 1- 3' Y Y Y Y? Aug -Sep
L -M S 1' Y Y Y ? ? Aug -Sep
M S 1' YYY'YY Apr -May
M S/PS 1' Y Y Y Y Y Apr -May
M -H S .5 - 2' Y Y Y Y ? Jul -Aug
M -H S .5-1' YYYYY May -Oct
L -H S/Sh 2- 2.5' Y Y Y Y? May -Oct
M S/PS 1' Y Y' Y Y? May -Jun
L -M S/PS 1' YYYYY May -Jun
M Sh .5 - 1.5' Y Y Y ? ? Mar -Apr
H Sh < 1' Y Y Y Y ? May -Jun
M -H S .5' Y Y'Y ? ? Jun
M -H S/PS .5 - 3'+ Y Y Y Y Jun -Jul
L -H S <.5' - 2' 'Y "Y Y Y Y May -Aug
H S/PS 2- 3' Y Y Y.Y ? Jul -Aug
M S 2-3' Y'Y`Y`Y Y Jul -Aug
H S/PS 3' N'Y'Y'Y`Y Jul -Aug
L -M S < 1' Y Y ? ? ? Jun -Jul
M S/PS <.5' Y Y Y Y Y Jun -Jul
M S/PS 1'+ Y'Y Y Y ? Jun -Jul
L -M S 1- 1.5' Y Y Y' Y Y Jul -Sep
M -H Sh <1' Y Y' Y Y Y May -Jun
M Sh/PS 2' Y Y Y Y Y May -Oct
M Sh/PS 2' Y Y Y Y May -Oct
M -H S/PS 1.5' Y !Y Y ? ? Jun
M S 1' ? ? ? Y Y ?
D-6
Helianthemum
nummularium
Helianthus pumilusa
Heuchera spp.
Ipomopsis aggregataa
,Iris germanica
;Iris missouriensis."
Lamium sp.b
Lavandula spp.
Leucocrinum
montanuma
;Liatris punctataa
Linum lewisiia`
Lupinus argenteusa`
;Mertensia lanceolataa
Mimulus guttatusa
;Monarda fistulosaa
Oenothera caespitosaa
Papaver orientale
Penstemon
;caespitosusab
Penstemon
secundorus
Penstemon
teucrioidesa
Penstemon virensa`
Phlox subulata
:Polemonium sp.
,Potentilla fissaa
Potentilla vernab
Pulsatilla patens'
;Ratibida columniferaa
;Rudbeckia hirtaa
Salvia officinalis
Rockrose
Small sunflower
'Coral bells
'Scarlet gilia
Bearded iris
'Missouri or Native iris
'Dead nettle
!Lavender
;Sand lily
:Dotted gayfeather
`Wild blue flax
;Silver lupine
;Narrow -leaved chiming
'bells
Yellow monkey -flower
'Native beebalm
White stemless evening
primrose
!Oriental poppy
Mat penstemon
Sidebells
;Germander penstemon
Blue mist penstemon
;Moss phlox
;Jacobs ladder
Leafy potentilla
;Spring potentilla
Pasque flower
;Prairie coneflower
Black-eyed Susan
'Cooking sage
M -H S < 1' Y Y Y ? ? May -Jun
M S 1 - 2' YY ? ? Jun -Jul
M -H PS/Sh 1- 2' Y Y Y Y Y Jun -Aug
M S/PS 1-2' Y Y Y Y Y Jun -Aug
L -M S 1- 3' Y Y Y' Y Y May -Jun
M -H S 1-2' YYY'YY May
M -H Sh < 1' Y Y Y Y ? May -Jun
L -M S 1- 2' Y Y Y ? ? Jun -Nov
L -M S < 1' Y Y Y? ? May
VL -L S 1- 2' Y `Y'Y Y Y Aug -Oct
L -H S/PS 1 -2' Y'Y YY Y May -Sep
M Sh/PS 1- 3' Y `Y'Y Y Y Jun -Jul
M -H Sh/PS 1- 2' Y Y 'YYY May -Jun
H Sh 1' ? Y Y'Y Y ?
M -H S/PS 1- 2' Y Y Y Y' Y Jul -Oct
L -M S 1- 2' Y Y' Y Y Y Jun -Aug
H S/Sh 2- 3' ¥YY Y Y May -Jun
L -M S < .5' YYY Y Y Jun
L -M S 1 - 2' YYY Y ? May -Jun
L -M S .5' Y Y Y? ? Jun -Jul
M S/PS .5' Y Y Y'Y'Y May -Jun
M S <.5' Y'YYYY May
H S/PS 1 - 2' Y Y Y Y ' Y' May -Aug
M -H PS 1' Y Y Y Y? ?
M -H PS <.5' Y Y Y'Y Y Mar -May
M S/PS 1' 'Y Y Y' Y Y Mar -May
L -M S 2' Y Y Y' Y Y Jul -Sep
M -H S 2 - 3' Y Y Y Y Y Jul -Sep
L -M S/PS 2' Y'Y'Y Y ? Jun
D-7
Saxaga hirsuta
Scutellaria brittonii
Sedum spp.b
:Sedum lanceolatum'
Sempervivum sp.
'Senecio spartioidesa`
Solidago
missouriensisa
,Thalictrum fendleri
Thermopsis
;divaricarpaa
Tradescantia
occidentalisa
Thymus sppb
Veronica pectinata
Vinca minorb
Waldsteinia sp.b
Arctostaphylos
nevadensieb
Arctostaphylos
patulaa
;Arctostaphylos uva-
ursiab
;Betula glanulosaa
;Callum sp.
;Ceanothus fendleri
Cercocarpus
intricatus
Cercocarpus
montanusa°
Chrysothamnus spp.a
'Cornus stoloniferaa
Cotoneaster
;horizontalis
!Saxifrage
Skullcap
Stonecrop
'Yellow stonecrop
Hens and chicks
Broom groundsel
Smooth goldenrod
Fendler meadowrue
;Spreading golden banner
'Western spiderwort
'Thyme
Speedwell
Periwinkle, myrtle
Barren strawberry
H S/PS
M S/PS
M S/PS
M S/PS
L -M S/PS
VL -L S
L -M
H
M -H
.5'+
.5 1'
1 - 1.5'
.5'
.5'
2 - 3'
S 1 - 2'
YYYY'Y
Y Y Y'Y ?
'Y'Y Y 'Y'Y
Y Y Y Y Y
Y Y'YY'Y
Y y ? ? ?
YY Y Y ?
May -Jun
Aug -Sep
Jul -Aug
Jul -Aug
n/a
Sep -Oct
Jul -Aug
S/PS 2 - 3' ? ? Y 'Y Y Jul -Aug
S/PS 2' Y Y Y Y ? May
M S/PS 1.5' 'Y YY Y ? Jun -Aug
L -M
L -M
H
M -H
Shrubs
Pinemat manzanita M
`Greenleaf manzanita M
!Kinnikinnick, bearberry M
'Bog birch H
]Heather H
IBuckbrush, mountain lilac M
;Little -leaf mountain VL -L
'mahogany
True mountain mahogany L -M
Rabbitbrush
Redtwig dogwood
Spreading cotoneaster
;Daphne burkwoodii ;Burkwood daphne
,Erica sp. 'Heath
VL -L
H
M
M
H
S
S
Sh
Sh/PS
< .5' YYYYY Jun -Jul
<.5' YYYYY Apr -Jul
< 1' Y Y 'Y Y ? Apr -Jun
< 1' Y Y Y Y ? May -Jun
S/PS 1 -2' Y Y`Y;N:N n/a
S/PS 3 - 4' Y'YY'•N N n/a
S/Sh
S/PS
S/PS
S
S
1' YYYYY n/a
6 - 8'
2'
2'
4 - 6'
YYYYY
Y'Y'y ? ?
y y y ? ?
Y
YY'Y ?
n/a
Jul -Aug
Jul
n/a
S 4-6' Y Y Y'Y ? n/a
S
S/Sh
S/PS
S/PS
S/PS
2-6' Y'Y`YY Y Jul -Aug
4 - 6' Y Y 'Y n/a
2 - 3' Y Y `Y 1Y ? May -Jun
2 - 3' Y Y Y ? ? Apr -Jun
1"Y Y Y ? ? Jan -Mar
D-8
Euonymus alatus
Fallugia paradoxaa
Holodiscus dumosusa
Jamesia americanaa
Lonicera tatarica
Mahonia aquifolium
Mahonia repensab
Philadelphus
microphyllusa
Physocarpus
monogynusa
Potentilla fruticosa°
;Prunus besseyia
Purshia tridentataa
Ribes aureuma
,Rosa woodsiia
;Shepherdia
canadensisa
Symphoricarpos spp.d
Viburnum edulea
,Yucca baccataa
Yucca filamentosa
Yucca glaucaa
Acer ginnala
Acer glabruma
Burning bush euonymus
,Apache plume
Ocean spray, cliff/rock
spirea
Wax flower
'Tatarian honeysuckle
Oregon grape holly
;Creeping grape holly
Little -leaf mockorange
;Mountain ninebark
;Shrubby cinquefoil
'Western sand cherry
;Antelope bitterbrush
;Golden currant
M
VL -L
L -M
M -H
M
M -H
L -H
M
S/Sh 1 - 6' YYY ? ? n/a
S
2 - 4' Y Y Y'Y Jun -Oct
S/PS 4' Y YY Y'Y Jun
S/Sh 2-6' YYYYY Jun
S/PS 4-6' YYYYY May -Jun
S/Sh 4- 6' Y Y Y? ? May -Jun
S/Sh 1 - 2' YYYYY Mar -May
S 2-3' YYYY ? Jun
M S/Sh 2-4' Y YYYY Jun
M S/PS
L -M S
L -M S
M S/PS
Woods' or native wild rose M S/PS
;Russet buffaloberry
Snowberry, coralberry
Highbush cranberry
;Banana or broad -leaf
;yucca
(Adams needle
'Spanish bayonet, small
soapweed, Great Plains
yucca
M -H S
M
H
VL -L
S/PS
S
S/PS
2 - 3'
1 - 3'
1 - 2'
2 - 3'
2 - 3'
5 - 6'
YYYYY May -Sep
YYYY ? May
Y Y Y ? ? Jun -Aug
`Y 'Y Y Y Y Apr -May
YYYYY Jun -Jul
YYYYY n/a
2-3' •Y•YYYY n/a
6 - 8' YYYYY May -Jun
2-3' Y'Y Y`N N Jun
M S/PS 2-3' YYY:NN Jun
VL -L S/PS 2-3' YYYY ? Jun
Large Shrubs and Trees
Ginnala maple
;Rocky Mountain maple
Acer grandidentatuma `Wasatch maple
Alnus tenuifoliaa
Amelanchier
alnifoliaa°
Amelanchier
utahensisa
;Betula fontinalisa
'Thinleaf alder
Saskatoon alder -leaf
serviceberry
Utah serviceberry
River birch
M -H
M -H
M
H
M
VL -M
S 6-10' YYYYY n/a
S/Sh 6-10' YYYYY n/a
S/PS 10 - 20' YYYY ? n/a
S/PS 6-8' YYYYY Apr
S/PS 6 - 8' YYY Y ' Y Apr -May
S 4 - 6' Y `Y N N'N May
H S/PS 6-8' YYYY ? n/a
D-9
Cercocarpus
ledifoliusa
Corylus cornutaa
Crataegus spp.a
:Fraxinus
pennsylvancia
Gleditsia triacanthos
.Malus sp.
Physocarpus
opulifoliusa
Populus tremuloidesa
Prunus americana
;Prunus cerasifera
Prunus
pennsylvanicaa
Prunus virginiana
•melanocarpaa°
Rubus deliciosusa
:Mountain mahogany
;Filbert, beaked hazelnut
Hawthorn (several native)
:Green ash
Honeylocust
Crabapple
'Tall ninebark
;Aspen
:American wild plum
',Flowering plum
Pin/fire/wild/red cherry
Western chokecherry
Boulder raspberry,
ithimbleberry
Salix amygdaloidesa :Peachleaf willow
Shepherdia argenteaa ;Silver buffaloberry
Sorbus scopulinaa ' Western mountain ash
Syringa vulgaris !Common lilac
-
b -
Native species.
Ground cover plant.
VL -L S 6-15' YY? N N n/a
H S/Sh 5 - 6' Y'Y Y ? ? n/a
M S 6-8' YYYY ? May
M -H S 20 - 25' Y Y Y'Y ? n/a
M -H
M
M
S
S
S/PS
60 - 70' Y'Y N''N N May
10 - 15' Y `Y Y Y N Apr -May
4-6' Y Y Y ? 'N May
M S 8-25'
M S/PS 4-6'
M S/PS 8 - 10'
M S/PS 6-8'
Y 'Y Y `Y Y n/a
Y'Y'Y Y Apr
Y Y Y ? 'N Apr
'Y Y Y ? 'N May
M -H S/PS 6- 8' YY Y Y Y Apr -May
M S/Sh 4- 6' Y Y Y Y Y Apr -May
H
M
M -H
S/PS 20 - 30' 'YYYY ?
S/PS 4-6' YYYY ?
S/Sh 6-8' Y Y'Y Y ?
M S 6-8' Y Y YYY
n/a
Apr
May
May
c - This species, or some species in this genus, may be poisonous to livestock, pets, wildlife and/or people
under some conditions. Before planting, check with Colorado State University Cooperative Extension,
Colorado State Forest Service, or other knowledgeable personnel.
d - Several speices of symphoricarpos are native.
D-10
INK
Appendix E
Creating Wildfire -Defensible Zones
by F.C. Dennis 1-- no. 6.302
Quick Facts
Wildfire will find the weakest links in the defense measures you have taken on your
property.
The primary determinants of a home's ability to survive wildfire are its roofing material
and the quality of the "defensible space" surrounding it.
Even small steps to protect your home and property will make them more able to
withstand fire.
Consider these measures for all areas of your property, not just the immediate vicinity of
the house.
Fire is capricious. It can find the weak link in your home's fire protection scheme and gain the
upper hand because of a small, overlooked or seemingly inconsequential factor. While you may
not be able to accomplish all measures below (and there are no guarantees), each will increase
your home's, and possibly your family's, safety and survival during a wildfire.
Start with the easiest and least expensive actions. Begin your work closest to your house and
move outward. Keep working on the more difficult items until you have completed your entire
project.
Defensible Space
Two factors have emerged as the primary determinants of a home's ability to survive wildfire.
These are the home's roofing material and the quality of the "defensible space" surrounding it.
Use fire -resistive materials (Class C or better rating), not wood or shake shingles, to roof homes
in or near forests and grasslands. When your roof needs significant repairs or replacement, do so
with a fire-resistant roofing material. Check with your county building department. Some
counties now restrict wood roofs or require specific classifications of roofing material.
Defensible space is an area around a structure where fuels and vegetation are treated, cleared or
reduced to slow the spread of wildfire towards the structure. It also reduces the chance of a
structure fire moving from the building to the surrounding forest. Defensible space provides
room for firefighters to do their jobs. Your house is more likely to withstand a wildfire if grasses,
brush, trees and other common forest fuels are managed to reduce a fire's intensity.
E-1
MEN a
The measure of fuel hazard refers to its continuity, both horizontal (across the ground) and
vertical (from the ground up into the vegetation crown). Fuels with a high degree of both vertical
and horizontal continuity are the most hazardous, particularly when they occur on slopes.
Heavier fuels (brush and trees) are more hazardous (i.e. produce a more intense fire) than light
fuels such as grass.
Mitigation of wildfire hazards focuses on breaking up the continuity of horizontal and vertical
fuels. Additional distance between fuels is required on slopes.
Creating an effective defensible space involves developing a series of management zones in
which different treatment techniques are used. See Figure 1 for a general view of the
relationships among these management zones. Develop defensible space around each building on
your property. Include detached garages, storage buildings, barns and other structures in your
plan.
The actual design and development of your defensible space depends on several factors: size and
shape of buildings, materials used in their construction, the slope of the ground on which the
structures are built, surrounding topography, and sizes and types of vegetation on your property.
These factors all affect your design. You may want to request additional guidance from your
local Colorado State Forest Service (CSFS) forester or fire department. (See the Special
Recommendations section of this fact sheet for shrubs, lodgepole pine, Engelmann spruce, and
aspen.)
Defensible Space Management Zones
Zone 1 is the area of maximum modification and
treatment. It consists of an area of 15 feet around
the structure in which all flammable vegetation is
removed. This 15 feet is measured from the
outside edge of the home's eaves and any
attached structures, such as decks.
flk
Zone 2 is an area of fuel reduction. It is a
•
transitional area between Zones 1 and 3. The size ��nii "`
of Zone 2 depends on the slope of the ground 'X )( )( )( 7t )( )( X X XX 7( X
where the structure is built. Typically, the
defensible space should extend at least 75 to 125
feet from the structure. See Figure 2 for the Forested property showing the three fire -defensible
appropriate distance for your home's defensible zones around a home or other structure.
space. Within this zone, the continuity and
arrangement of vegetation is modified. Remove stressed, diseased, dead or dying trees and
shrubs. Thin and prune the remaining larger trees and shrubs. Be sure to extend thinning along
either side of your driveway all the way to your main access road. These actions help eliminate
the continuous fuel surrounding a structure while enhancing homesite safety and the aesthetics of
the property.
E-2
xdS
}
Zone 3 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.
Prescriptions
/,OH( t
The size of Zone 1 is 15 feet, measured from the
edges of the structure. Within this zone, several
specific treatments are recommended.
Plant nothing within 3 to 5 feet of the structure,
particularly if the building is sided with wood,
logs or other flammable materials. Decorative
rock, for example, creates an attractive, easily
maintained, nonflammable ground cover.
pi)ill Gold Nide)
, :1;; 1 1 ,. i 1.1)
E)i%lance lo home
This chart indicates the minimum recommended
dimensions for defensible space from the home to the
outer edge of Zone 2. For example, if your home is
situated on a 20 percent slope, the minimum
defensible space dimensions would be 90 feet uphill
and to the sides of the home and 104 feet downhill
from the home.
If the house has noncombustible siding, widely
spaced foundation plantings of low growing shrubs or other "fire wise" plants are acceptable. Do
not plant directly beneath windows or next to foundation vents. Be sure there are no areas of
continuous grass adjacent to plantings in this area.
Frequently prune and maintain plants in this zone to ensure vigorous growth and a low growth
habit. Remove dead branches, stems and leaves.
Do not store firewood or other combustible materials in this area. Enclose or screen decks with
metal screening. Extend the gravel coverage under the decks. Do not use areas under decks for
storage.
Ideally, remove all trees from Zone 1 to reduce fire hazards. If you do keep a tree, consider it
part of the structure and extend the distance of the entire defensible space accordingly. Isolate the
tree from any other surrounding trees. Prune it to at least 10 feet above the ground. Remove any
branches that interfere with the roof or are within 10 feet of the chimney. Remove all "ladder
fuels" from beneath the tree. Ladder fuels are vegetation with vertical continuity that allows fire
to burn from ground level up into the branches and crowns of trees. Ladder fuels are potentially
very hazardous but are easy to mitigate. No ladder fuels can be allowed under tree canopies. In
all other areas, prune all branches of shrubs or trees up to a height of 10 feet above ground (or 1/2
the height, whichever is the least).
E-3
Zone 2
Zone 2 is an area of fuel reduction designed to
reduce the intensity of any fire approaching
your home. Follow these recommended
management steps.
Thin trees and large shrubs so there is at least
10 feet between crowns. Crown separation is
measured from the furthest branch of one tree
to the nearest branch on the next tree (Figure
3). On steep slopes, allow more space between
tree crowns. (See Figure 4 for minimum
recommended spacing for trees on steep
slopes.) Remove all ladder fuels from under
these remaining trees. Carefully prune trees to a
height of at least 10 feet.
Small clumps of 2 to 3 trees may be
occasionally left in Zone 2. Leave more space
between the crowns of these clumps and
surrounding trees.
Y
}
X = crown spacing; Y = stem spacing. Do not measure
Because Zone 2 forms an aesthetic buffer and between stems for crown -- measure between the edges
provides a transition between zones, it is of tree crowns.
necessary to blend the requirements for Zones 1
and 3. Thin the portions of Zone 3 adjacent to Zone 2 more heavily than the outer portions.
Isolated shrubs may remain, provided they are not under tree crowns. Prune and maintain these
plants periodically to maintain vigorous growth. Remove dead stems from trees and shrubs
annually. Where shrubs are the primary fuel in Zone 2, refer to the Special Recommendations
section of this fact sheet.
Limit the number of dead trees (snags) retained in this area. Wildlife needs only one or two snags
per acre. Be sure any snags left for wildlife cannot fall onto the house or block access roads or
driveways.
Mow grasses (or remove them with a weed trimmer) as needed through the growing season to
keep them low, a maximum of 6 to 8 inches. This is extremely critical in the fall when grasses
dry out and cure or in the spring after the snow is gone but before the plants green up.
Stack firewood and woodpiles uphill or on the same elevation as the structure but at least 30 feet
away. Clear and keep away flammable vegetation within 10 feet of these woodpiles. Do not
stack wood against your house or on or under your deck, even in winter. Many homes have
E-4
L
r-
burned from a woodpile that ignited as the fire passed. Wildfires can burn at almost any time in
Colorado.
Locate propane tanks at least 30 feet from any structures, preferably on the same elevation as the
house. You don't want the LP container below your house — if it ignites, the fire would tend to
burn uphill. On the other hand, if the tank is above your house and it develops a leak, LP gas will
flow downhill into your home. Clear and keep away flammable vegetation within 10 feet of these
tanks. Do not screen propane tanks with shrubs or vegetation.
Minimum tree crown and shrub clump spacing.
% slope Tree Crown Spacing Brush and Shrub Clump Spacing
0 -10 % 10' 2 1/2 x shrub height
11 - 20% 15' 3 x shrub height
21 - 40% 20' 4 x shrub height
> 40% 30' 6 x shrub height
Dispose of slash (limbs, branches and other woody debris) from your trees and shrubs through
chipping or by piling and burning. Contact your local CSFS office or county sheriff's office for
information about burning slash piles. If neither of these alternatives is possible, lop and scatter
slash by cutting it into very small pieces and distributing it over the ground. Avoid heavy
accumulations of slash. Lay it close to the ground to speed decomposition. If desired, no more
than two or three small, widely spaced brush piles may be left for wildlife purposes. Locate these
towards the outer portions of your defensible space.
E-5
Zone 3
This zone is of no specified size. It extends from the edge of your defensible space to your
property lines. A gradual transition into this zone from defensible space standards to other
management objectives you may have is suggested. Typical management objectives for areas
surrounding homesites or subdivisions are: provide optimum recreational opportunities; enhance
aesthetics; maintain tree health and vigor; provide barriers for wind, noise, dust and visual
intrusions; support limited production of firewood, fence posts and other forest commodities; or
grow Christmas trees or trees for transplanting.
Minimum tree spacing for Zone 3
Tree Average Stem Spacing
Diameter (in Between Trees (in feet)
inches)
3 10
4 11
5 12
6 13
7 14
8 15
9 16
10 17
11 19
12 21
13 23
14 24
15 26
16 28
17 29
18 31
19 33
20 35
21 36
22 38
23 40
24 42
Specific requirements will be dictated by your objectives for your land and the kinds of trees
present. See Figure 5 for the minimum suggested spacing between "leave" trees. Forest
management in Zone 3 is an opportunity for you to increase the health and growth rate of the
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forest in this zone. Keep in mind that root competition for available moisture limits tree growth
and ultimately the health of the forest.
A high canopy forest reduces the chance of a surface fire climbing into the tops of the trees and
might be a priority for you if this zone slopes steeply. The healthiest forest is one that has
multiple ages, sizes, and species of trees where adequate growing room is maintained over time.
Remember to consider the hazards of ladder fuels. Multiple sizes and ages of trees might
increase the fire hazard from Zone 3 into Zone 2, particularly on steep slopes.
A greater number of wildlife trees can remain in Zone 3. Make sure that dead trees pose no threat
to power lines or fire access roads.
While pruning generally is not necessary in Zone 3, it may be a good idea from the standpoint of
personal safety to prune trees along trails and fire access roads. Or, if you prefer the aesthetics of
a well -manicured forest, you might prune the entire area. In any case, pruning helps reduce
ladder fuels within the tree stand, thus enhancing wildfire safety.
Mowing is not necessary in Zone 3.
Any approved method of slash treatment is acceptable for this zone, including piling and
burning, chipping or lop -and -scatter.
Special Recommendations
Tree spacing guidelines do not apply to mature stands of aspen trees where the recommendations
for ladder fuels have been complied with. In areas of aspen regeneration and young trees, the
spacing guidelines should be followed.
Brush and shrubs
Brush and shrubs are woody plants, smaller than trees, often formed by a number of vertical or
semi-upright branches arising close to the ground. Brush is smaller than shrubs and can be either
woody or herbaceous vegetation.
On nearly level ground, minimum spacing recommendations between clumps of brush and/or
shrubs is 2 1/2 times the height of the vegetation. Maximum diameter of clumps should be 2
times the height of the vegetation. As with tree crown spacing, all measurements are made from
the edges of vegetation crowns (Figure 3).
For example: For shrubs 6 feet high, spacing between shrub clumps should be 15 feet or more
apart (measured from the edges of the crowns of vegetation clumps). The diameter of shrub
clumps should not exceed 12 feet (measured from the edges of the crowns). Branches should be
pruned to a height of 3 feet.
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nit
Grasses
Keep dead, dry or curing grasses mowed to less than 6 inches. Defensible space size where grass
is the predominant fuel can be reduced (Figure 5) when applying this practice.
Wimith row
In Colorado, certain locations and tree species, including lodgepole pine and Engelmann spruce,
are especially susceptible to damage and uprooting by high winds (windthrow). If you see
evidence of this problem in or near your forest, or have these tree species, consider the following
adjustments to the defensible space guidelines. It is highly recommended that you contact a
professional forester to help design your defensible space.
Adjustments: If your trees or homesite are susceptible to windthrow and the trees have never
been thinned, use a stem spacing of diameter plus five instead of the guides listed in the Zone 3
section. Over time (every 3 to 5 years) gradually remove additional trees. The time between
cutting cycles allows trees to "firm up" by expanding their root systems. Continue this periodic
thinning until the desired spacing is reached.
Also consider leaving small clumps of trees and creating small openings on their lee side
(opposite of the predominant wind direction). Again, a professional forester can help you design
the best situation for your specific homesite and tree species. Remember, with species such as
lodgepole pine and Engelmann spruce, the likelihood of a wildfire running through the tree tops
or crowns (crowning) is closely related to the overabundance of fuels on the forest floor. Be sure
to remove downed logs, branches and excess brush and needle buildup.
Minimum defensible space size for grass fuels.
slope D -space size (uphill, downhill,
sidehill)
0-20% 30'
21 - 40% 50'
> 40% 70'
Maintaining Your Defensible Space
Your home is located in a forest that is dynamic, always changing. Trees and shrubs continue to
grow, plants die or are damaged, new plants begin to grow, and plants drop their leaves and
needles. Like other parts of your home, defensible space requires maintenance. Use the following
checklist each year to determine if additional work or maintenance is necessary.
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Foam
Defensible Space and FireWise Annual Checklist
LI Trees and shrubs are properly thinned and pruned within the defensible space. Slash from
the thinning is disposed of.
D Roof and gutters are clear of debris.
❑ Branches overhanging the roof and chimney are removed.
❑ Chimney screens are in place and in good condition.
❑ Grass and weeds are mowed to a low height.
Li An outdoor water supply is available, complete with a hose and nozzle that can reach all
parts of the house.
IJ Fire extinguishers are checked and in working condition.
LI The driveway is wide enough. The clearance of trees and branches is adequate for fire
and emergency equipment. (Check with your local fire department.)
LJ Road signs and your name and house number are posted and easily visible.
-' There is an easily accessible tool storage area with rakes, hoes, axes and shovels for use
in case of fire.
You have practiced family fire drills and your fire evacuation plan.
Your escape routes, meeting points and other details are known and understood by all
family members.
O Attic, roof, eaves and foundation vents are screened and in good condition. Stilt
foundations and decks are enclosed, screened or walled up.
❑ Trash and debris accumulations are removed from the defensible space.
❑ A checklist for fire safety needs inside the home also has been completed. This is
available from your local fire department.
References
Colorado State Forest Service, Colorado State University, Fort Collins, CO 80523-5060; (970)
491-6303:
• FireWise Construction -- Design and Materials
Home Fire Protection in the Wildland Urban Interface
Wildfire Protection in the Wildland Urban Interface
• Landowner Guide to Thinning
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Colorado State University Cooperative Extension, 115 General Services Bldg., Fort Collins, CO
80523-4061; (970) 491-6198; E-mail: resourcecenter@ucm.colostate.edu.
6.303, Fire -Resistant Landscaping
6.304, Forest Home Fire Safety
6.305, FireWise Plant Materials
6.306, Grass Seed Mixes to Reduce Wildfire Hazard
7.205, Pruning Evergreens
7.206, Pruning Shrubs
7.207, Pruning Deciduous Trees
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Appendix F
Fire -Resistant Landscaping
by F.C. Dennis'° -- no. 6.303
Quick Facts
More people are moving into Colorado's rural areas, increasing the chances of wildfire.
"Defensible space" is the primary determinant of a structure's ability to survive wildfire.
Native species are generally the best plant materials for landscaping in defensible space,
but others can be grown successfully in Colorado.
To be a FireWise homeowner, plan well, plant well and maintain well.
Colorado's population is growing, its urban areas are rapidly expanding, and people are building
more homes in what was once natural forest and brushlands. Newcomers to rural areas need to
know how to correctly landscape their property to reduce wildfire hazards.
Improper landscaping worries land managers and fire officials because it can greatly increase the
risk of structure and property damage from wildfire. It is a question of when, not if, a wildfire
will strike any particular area.
Vegetative clearance around the house (defensible space) is a primary determinant of a home's
ability to survive wildfire. Defensible space is, simply, room for firefighters to do their job. If
grasses, brush, trees and other common forest fuels are removed, reduced, or modified to lessen a
fire's intensity and keep it away from the home, chances increase that the structure will survive.
It is a little-known fact that in the absence of a defensible space, firefighters will often bypass a
house, choosing to make their stand at a home where their safety is more assured and the chance
to successfully protect the structure is greater.
Landscaping Defensible Space
People often resist creating defensible space because they believe that it will be unattractive,
unnatural and sterile -looking. It doesn't have to be! Wise landowners carefully plan landscaping
within the defensible space. This effort yields a many -fold return of beauty, enjoyment and
added property value. Development of defensible space is outlined in fact sheet 6.302, Creating
Wildfire -Defensible Zones.
Colorado has great diversity in climate, geology and vegetation. Home and cabin sites can be
found from the foothills through 10,000 -foot elevations. Such extremes present a challenge in
'° Wildfire Hazard Mitigation Coordinator, Colorado State Forest Service. This fact sheet was produced in cooperation with
the Colorado State Forest Service. FIREWISE is a multi -agency program that encourages the development of defensible
space and the prevention of catastrophic wildfire. 5/99. Reviewed 10/04.
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recommending plants. While native plant materials generally are best, a wide range of species
can be grown successfully in Colorado. Many plant species are suitable for landscaping in
defensible space. Use restraint and common sense, and pay attention to plant arrangement and
maintenance. It has often been said that how and where you plant are more important than what
you plant. While this is indeed true, given a choice among plants, choose those that are more
resistant to wildfire.
Consider the following factors when planning, designing and planting the FireWise landscape
within your home's defensible space:
• Landscape according to the recommended defensible -space zones. That is, the plants near
your home should be more widely spaced and lower growing than those farther away.
• Do not plant in large masses. Instead, plant in small, irregular clusters or islands.
Use decorative rock, gravel and stepping stone pathways to break up the continuity of the
vegetation and fuels. This can modify fire behavior and slow the spread of fire across
your property.
• Incorporate a diversity of plant types and species in your landscape. Not only will this be
visually satisfying, but it should help keep pests and diseases from causing problems
within the whole landscape.
* In the event of drought and water rationing, prioritize plants to be saved. Provide
available supplemental water to plants closest to your house.
• Use mulches to conserve moisture and reduce weed growth. Mulch can be organic or
inorganic. Do not use pine bark, thick layers of pine needles or other mulches that readily
carry fire.
• Be creative! Further vary your landscape by including bulbs, Garden art and containers
for added color.
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Forested property surrounding a homesite; shows optimum placement of vegetation near the
structure.
A. Mow grass short around shrubs.
B. The best tree species to plant generally are those naturally occurring on or near the site.
C. Plant low -growing, non -resinous shrubs near structures.
D. Keep grass mown around structure to a maximum of 8 inches.
E. Plant wildflowers near structures only if they are well -irrigated and cut back during the
dormant season.
F. Gravel area or mow grass short next to the structure.
rasses
During much of the year, grasses ignite easily and burn rapidly. Tall grass will quickly carry fire
to your house. Mow grasses low in the inner zones of the defensible space. Keep them short
closest to the house and gradually increase height outward from the house, to a maximum of 8
inches. This is particularly important during fall, winter and before green -up in early spring,
when grasses are dry, dormant and in a "cured" fuel condition. Given Colorado's extremely
variable weather, wildfires can occur any time of the year. Maintenance of the grassy areas
around your home is critical.
Mow grasses low around the garage, outbuildings, decks, firewood piles, propane tanks, shrubs,
and specimen trees with low -growing branches.
Ground Cover lelarits
Replace bare, weedy or unsightly patches near your home with ground covers, rock Gardens,
vegetable Gardens and mulches. Ground cover plants are a good alternative to grass for parts of
your defensible space. They break up the monotony of grass and enhance the beauty of your
landscape. They provide a variety of textures and color and help reduce soil erosion. Consider
ground cover plants for areas where access for mowing or other maintenance is difficult, on steep
slopes and on hot, dry exposures.
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Ground cover plants are usually low growing. They are succulent or have other FireWise
characteristics that make them useful, functional and attractive. When planted in beds surrounded
by walkways and paths, in raised beds or as part of a rock Garden, they become an effective
barrier to fire spread. The ideal groundcover plant is one which will spread, forming a dense mat
of roots and foliage that reduces soil erosion and excludes weeds.
Mulch helps control erosion, conserve moisture and reduce weed growth. It can be organic
(compost, leaf mold, bark chips, shredded leaves) or it can be inorganic (gravel, rock,
decomposing granite).
When using organic mulches, use just enough to reduce weed and grass growth. Avoid thick
layers. When exposed to fire, they tend to smolder and are difficult to extinguish. Likewise,
while your property might yield an abundance of needles from your native pines or other
conifers, don't use them as mulch because they can readily catch and spread wildfire. Rake,
gather and dispose of them often within your defensible space.
Wildflowers
Wildflowers bring variety to a landscape and provide color from May until frost. Wildflower
beds give a softer, more natural appearance to the otherwise manicured look often resulting from
defensible space development.
A concern with wildflowers is the tall, dense areas of available fuel they can form, especially in
dormancy. To reduce fire hazard, plant wildflowers in widely separated beds within the
defensible space. Do not plant them next to structures unless the beds are frequently watered and
weeded and vegetation is promptly removed after the first hard frost. Use gravel walkways, rock
retaining walls or irrigated grass areas mowed to a low height to isolate wildflower beds from
each other and from other fuels.
Shrubs
Shrubs lend color and variety to the landscape and provide cover and food for wildlife. However,
shrubs concern fire professionals because, as the next level in the "fuel continuum," they can add
significantly to total fuel loading. Because of the woody material in their stems and branches,
they are a potential source of fire brands. When carried in the smoke column ahead of the main
fire, fire brands can rapidly spread the fire in a phenomenon known as "spotting."
But the primary concern with shrubs is that they are a "ladder fuel" -- they can carry a relatively
easy -to -control surface grass fire into tree crowns. Crown fires are difficult, sometimes
impossible, to control.
To reduce the fire -spreading potential of shrubs, plant only widely separated, low -growing,
nonresinous varieties close to structures. Do not plant them directly beneath windows or vents or
where they might spread under wooden decks. Do not plant shrubs under tree crowns or use
them to screen propane tanks, firewood piles or other flammable materials. Plant shrubs
individually, as specimens, or in small clumps apart from each other and away from any trees
within the defensible space.
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a
Mow grasses low around shrubs. Prune dead stems from shrubs annually. Remove the lower
branches and suckers from species such as Gambel oak to raise the canopy away from possible
surface fires.
Trees
Trees provide a large amount of
available fuel for a fire and can be a
significant source of fire brands if they
do burn. Radiant heat from burning
trees can ignite nearby shrubs, trees and
structures.
Colorado's elevation and temperature
extremes limit tree selection. The best
species to plant generally are those
already growing on or near the site.
Others may be planted with careful
selection and common sense.
Ladder fuels enable fire to travel from the ground surface into
shrubs and then into the tree canopy.
If your site receives enough moisture to grow them, plant deciduous trees such as aspen or
narrow -leaf cottonwood. These species, even when planted in dense clumps, generally do not
burn well, if at all. The greatest problem with these trees is the accumulation of dead leaves in
the fall. Remove accumulations close to structures as soon as possible after leaf drop.
When site or available moisture limits recommended species to evergreens, carefully plan their
placement. Do not plant trees near structures. Leave plenty of room between trees to allow for
their growth. Spacing within the defensible space should be at least 10 feet between the edges of
tree crowns. On steep ground, allow even more space between crowns. Plant smaller trees
initially on a 20- to 25 -foot spacing to allow for tree growth. At some point, you will have to thin
your trees to retain proper spacing.
As the trees grow, prune branches to a height of 10 feet above the ground. Do not overprune the
crowns. A good rule of thumb is to remove no more than one-third of the live crown of the tree
when pruning. Prune existing trees as well as ones you planted.
Some trees (for example, Colorado blue spruce) tend to keep a full crown. Other trees grown in
the open may also exhibit a full growth habit. Limit the number of trees of this type within the
defensible space. Prune others as described above and mow grasses around such specimen trees.
6d- ,uco alb ag EMe*rtee rds of a Fel•ea iSe La IMIScxepe
When building a deck or patio, use concrete, flagstone or rock instead of wood. These materials
do not burn and do not collect flammable debris like the space between planks in wooden
decking.
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Where appropriate on steeper ground, use retaining walls to reduce the steepness of the slope.
This, in turn, reduces the rate of fire spread. Retaining walls also act as physical barriers to fire
spread and help deflect heat from the fire upwards and away from structures.
Rock or masonry walls are best, but even wooden tie walls constructed of heavy timbers will
work. Put out any fires burning on tie walls after the main fire front passes.
On steep slopes, consider building steps and walkways around structures. This makes access
easier for home maintenance and enjoyment. It also serves as a physical barrier to fire spread and
increases firefighters' speed and safety as they work to defend your home.
Maintenance
A landscape is a dynamic system that constantly grows and changes. Plants considered fire
resistant and which have low fuel volumes can lose these characteristics over time. Your
landscape, and the plants in it, must be maintained to retain their FireWise properties.
• Always keep a watchful eye towards reducing the fuel volumes available to fire. Be
aware of the growth habits of the plants within your landscape and of the changes that
occur throughout the seasons.
Remove annuals and perennials after they have gone to seed or when the stems become
overly dry.
• Rake up leaves and other litter as it builds up through the season.
• Mow or trim grasses to a low height within your defensible space. This is particularly
important as grasses cure.
• Remove plant parts damaged by snow, wind, frost or other agents.
Timely pruning is critical. Pruning not only reduces fuel volumes but also maintains
healthier plants by producing more vigorous, succulent growth.
• Landscape maintenance is a critical part of your home's defense system. Even the best
defensible space can be compromised through lack of maintenance. The old adage "An
ounce of prevention is worth a pound of cure" applies here.
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r
r
t
References
• 6.302, Creating Wild -Fire Defensible Zones
Y 6.304, Forest Home Fire Safety
4 6.305, Fire Wise Plant Materials
4 6.306, Grass Seed Mixes to Reduce Wildfire Hazard
• 7.205, Pruning Evergreens
• 7.206, Pruning Shrubs
• 7.207, Pruning Deciduous Trees
• 7.233, Wildflowers for Colorado
• 7.406, Flowers for Mountain Communities
• 7.413, Ground Covers for Mountain Communities
• 7.423, Trees and Shrubs for Mountain Areas
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