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Community Wildfire Protection Considerations for Wildland Urban
Interface Management in Submitted by: B.A. Blackwell and Associates Ltd. V7J 3B5 Submitted to: Terry McEachen General Manager of Community and Development Services Regional District of Fraser-Fort George |
Executive Summary
B.A. Blackwell and Associates Ltd. were
retained to develop a Community Wildfire Protection Plan (CWPP) for
The community of
The Community of Bear Lake has experienced enormous pine mortality as a result of extensive mountain pine beetle infestation, which has contributed to increased fuel hazard in close proximity to the community.
A spatial Wildfire Risk Management System (WRMS) was developed to identify key areas of risk within the study area and to support the development of the Plan. The probability of wildfire was moderate to high in the study area. However, the volume of red-attack (dead needles still attached) lodgepole pine around the community has created an elevated fuel hazard and current fuel type models do not include a dead pine fuel type; therefore, probability may be underestimated. The consequence of wildfire ranges from moderate to extreme.
The CWPP provides the community of
Table of Contents
1.2 Documentation of Process Undertaken
and Major Milestones
2.0 The Community of Bear Lake
4.0 The Wildland Urban Interface
4.1 Vulnerability of the Wildland Urban
Interface to Fire
5.0 Mountain Pine Beetle and Fire Hazard
6.1 Vegetation (Fuel) Management
6.1.4 Time-line
for Implementation
6.2 Communication and Education
8.0 Debris Utilization Options
10.0 Recommendations on Lessons Learned
Appendix A – Fuel Type Descriptions
Appendix B – Operational Fuel Treatment Funding
Application
Appendix C – Forest Licence to Cut for Community
Protection Sample
Appendix D – WRMS and Resultant Maps
List of Figures
Figure
1. Community Wildfire Protection Plan development process.
Figure 5. Graphical example showing variation in the
definition of interface.
Figure 8. Wildland urban interface continuum.
Figure 9. 2006 mountain pine beetle incidence in the
study area.
Figure 11. Example of a C4 fuel type in the community.
Figure 12. Example of home with an open deck.
Figure 13. Example of home with inadequate setback to
forest vegetation.
List of Tables
Table
1. BEC Area Summary for the total CWPP study area
Table 3. Fire history summary within the study area from
1950 - 2005.
Table 4. Summary of fire cause within the study area.
Table 5. Fuel type polygons that are a priority for
treatment consideration.
List of Maps
Map
1. Ownership map of Bear Lake study area.
Map 2. Fuel type map of Bear Lake study area.
Map 3. Historic ignitions in the Bear Lake study area.
Map 4. Probability and Consequence of wildfire in Bear
Lake
Map 5. Hazardous fuel types within the study area.
Map 6. Areas prioritized for fuel treatment.
1.0 Introduction
In 2007 B.A. Blackwell and Associates Ltd. were retained to assist
the Regional District of Fraser-Fort George (RDFFG) and the community of
When considering wildfire risk in the wildland urban interface
(WUI), it is important to understand the specific risk profile of a given
community, which can be defined by the probability and the associated
consequence of fire within that community. The probability of fire around the
The CWPP will provide the community of
1.1
How
to Use this Document
This document is to be used by the Bear Lake Community Commission and RDFFG staff to provide guidance for mitigation of fire risk within the study area.
Sections 2.0 to 6.0 describe the study area, its fire environment, the community risk profile and provide some background on urban interface and mountain pine beetle related fire hazard. Section 7.0 contains the Action Plan, which outlines wildfire protection issues and presents recommendations to address them. This is the portion of the document that presents the key steps to be taken to better protect the community. Sections 8.0 to 10.0 outline fuel treatment, debris utilization and policy options that exist to facilitate implementation of recommendations. Section 11.0 lists recommendations based on lessons learned. Section 12.0 contains all map frames referred to in the document.
1.2
Documentation
of Process Undertaken and Major Milestones
This CWPP was developed in consultation with the Bear Lake Community
Commission and the RDFFG. The project was funded by the RDFFG and a
supplementary grant from the Union of B.C. Municipalities with the support of
the B.C. Ministry of Forests. The purpose of the Plan is to quantify and
identify fire risk within the community of
The scope of this project included three distinct phases of work:
· Phase I – Assessment of fire risk and development of a Wildfire Risk Management System to spatially quantify the probability and consequence of fire.
· Phase II – Identification of hazardous fuel types and fire protection issues in the field.
· Phase III – Development of the Plan and mapping, which outline measures to mitigate the identified risk through fuel treatments, emergency response, training, communication, and education.
· Phase IV – Consultation with the community and stakeholder groups.
Figure 1 demonstrates the CWPP process. The Wildfire Risk Management
S
Figure 1. Community Wildfire Protection Plan development process.
2.0
The
Community of Bear Lake
2.1
Study
Area
The
community of
The total study area that makes up this plan includes the approximate community boundary and a 2 km buffer that consists of map sheet numbers 93J047 and 93J057. The total study area is 3,849 ha. An ownership map of the study area is shown in Map 1.
Figure
2. View of topographic
relief of the Community of
The 2001 Census recorded the population of
The
3.0
Fire
Environment
3.1
Fire
Weather
The Canadian Forest Fire Danger Rating S
It is important to understand the likelihood of exposure to periods
of high fire danger, defined as Danger Class IV (high) and V (extreme), in
order to determine appropriate prevention programs, levels of response, and
management strategies. Fire danger within the study area can vary from season
to season. The study area is predominantly defined in Biogeoclimatic Ecos
Table 1.
|
BEC Unit |
% of Total Study Area |
Area within Total Study Area (ha) |
|
SBS wk 1 |
21 |
803.12 |
|
SBS mk 1 |
79 |
3,045.70 |
|
Total |
|
3,848.81 |
Fire danger within the study area can vary significantly from season
to season. Figure 3 is a compilation of available weather station data
within the SBS mk biogeoclimatic unit (representative of the study area). These
records date back to 1946 and provide a summary of the total number of Danger
Class IV and V-da
Figure 3. Seasonal variability
(April-October) in the number of Danger Class IV and V-da
A summary of historic drought codes for the SBS mk provides a
similar comparison to danger class da
Figure 4. Summary of seasonal (April-October) high and low drought codes by year
in the SBS mk within the study area.
The results of the weather data analysis show that, historically in the SBS mk, there have been a number of years when fire danger in the study area has been high during the summer months. The relatively short length of the record limits the confidence with which conclusions can be drawn from this data. While the results indicate that fire weather is generally less extreme in the SBS mk than in drier ecosystems, complacency is an inappropriate response to fire risk due to the fuel hazards surrounding the community.
3.2
Fuels
Fuel classification was based on the Canadian Forest Fire Danger Rating System (CFFDRS) and a summary of fuel type attributes collected in the field. An algorithm that uses input from Vegetation Resource Inventory (VRI) data was developed to gain a better approximation of CFFDRS fuel types for the study area. The Ministry of Forests and Range fuel typing was improved upon and adjusted to incorporate local variation. For each type identified, we have attempted a best approximation of the CFFDRS classification.
3.2.1
Fuel
Type Summary
Table 2 summarizes the fuel types by area. A fuel type map is shown in Map 2. A description of each fuel type is provided in Appendix A. The majority of the study area falls within fuel types C3 and C4; these fuel types are considered hazardous due to the high fire behaviour they tend to exhibit.
Table 2. Summary of fuel types based on the total study area not including area attributable to ocean
|
Fuel Type |
C3 |
C4 |
C7 |
D1 |
M2 |
O1a |
O1b |
Non-fuel |
Total |
|
Area (ha) |
1,603 |
871 |
135 |
1 |
310 |
213 |
342 |
373 |
3,847 |
|
% |
42 |
23 |
4 |
<1 |
8 |
6 |
9 |
10 |
100 |
3.3
Historic
Ignitions
The MOFR fire reporting s
Table 3 summarizes the fires that have occurred between 1950 and 2005 in the study area by size class and cause (lightning and human caused). The total number of fires during this period was 17, of which 71% were the result of human causes. The remaining 29% of fire ignitions were lightning caused. All of the fires that burned between 1950 and 2005 were smaller than four hectares. The largest fire within the study area since 1950 occurred in 1987 and burned an area of 1.0 hectare.
Table 4 summarizes fire cause by decade. Through the time of record, human caused fires have far out-numbered those caused by lightning. On average, there have been 2.8 fires each decade (minimum 0 in the decade 2000-2005 and maximum 7 in the ‘70s). The majority of fires have been inconsequential in size. The small size of the study area should be noted when interpreting these results.
Table 3. Fire history summary within the study area from 1950 - 2005.
|
Size Class
(ha) |
Total
Number of Fires |
% of Total |
Lightning
Caused |
Human
Caused |
|
<4.0 |
17 |
100 |
5 |
12 |
|
4.0-10.0 |
0 |
0 |
- |
- |
|
>10.0 |
0 |
0 |
- |
- |
|
Total Fires |
17 |
100 |
5 |
12 |
Table 4. Summary of fire cause within the study area.
|
Decade |
Lightning |
Direct
Human1 |
Industrial2 |
Total |
|
1950-1959 |
2 (67) |
1 (33) |
- |
3 |
|
1960-1969 |
- |
2 (100) |
- |
2 |
|
1970-1979 |
- |
7 (100) |
- |
7 |
|
1980-1989 |
1 (33) |
2 (67) |
- |
3 |
|
1990-1999 |
2 (100) |
- |
- |
2 |
|
2000-2005 |
- |
- |
- |
- |
|
Total Fires |
5 (29) |
12 (71) |
- |
17 |
1 Campfire, smoker, incendiary, juvenile set, fire use
2 Equipment, railway
Note: Numbers in parentheses ( ) indicate percentage of total fires for a given decade.
4.0
The
Wildland Urban Interface
The classical definition of wildland urban interface (WUI) is the place where the “forest meets the community” and is graphically depicted in Figure 5. Other configurations of the WUI can be described as intermixed. Intermixed areas include smaller, more isolated developments that are embedded within the forest.
In each of these cases, fire has the ability to spread from the forest into the community or from the community out into the forest. Although these two scenarios are quite different, they are of equal importance when considering interface fire risk. The probability of a fire moving out of a community and into the forest is equal to or greater than the probability of fire moving from the forest into a community.
The community of
Figure 5. Graphical example showing variation in the definition of interface.
4.1
Vulnerability
of the Wildland Urban Interface to Fire
Fires spreading into the WUI from the
forest can impact homes in two distinct wa
Figure 6. Firebrand caused ignitions: burning embers are carried ahead of the fire front and alight on vulnerable building surfaces.
Figure 7. Radiant heat and flame contact allows fire to spread from vegetation to structure or from structure to structure.
The wildland urban interface continuum (Figure 8) summarizes the main options available for addressing WUI fire risk in the Community Wildfire Protection Planning process.
Figure 8. Wildland urban interface continuum.
The appropriate management response to a given wildfire risk profile is based on the combination and level of emphasis of several key elements:
·
Communication
and education.
·
Emergency
response.
·
Training.
·
Structure
protection.
·
Vegetation
management.
·
Post-fire
rehabilitation.
For example, in an interface area with a high-risk profile, equal weight may be
given to all elements. Alternatively, in this same high-risk example, active
intervention through vegetation management may be given a higher emphasis. This
change in emphasis is based on the values at risk (consequence) and level of
desired protection required. In a low risk situation the emphasis may be on
communication and education combined with emergency response and training. In
other words, a variety of management responses are appropriate within a given
community and these can be determined based on the Community Risk Profile.
In the case of
5.0
Mountain
Pine Beetle and Fire Hazard
Mountain pine beetle mortality results in an initial short-term increase in stand level fire hazard when trees are in the red-attack stage, and for some time into the grey-attack stage, while fine fuels are still present in the canopy. Trees enter the red-attack stage approximately one year following infestation and turn grey approximately three years following infestation. As needles and small branches fall from the canopy and decompose, stand level fire hazard decreases. After approximately ten years, the fire hazard begins to increase as bark begins to slough off the standing dead trees[2]. Hazard then drops again until the beetle killed trees begin to fall (approximately 20 years), at which point the fire hazard rises to high or extreme depending on the quantity and arrangement of fuel that results from the falling trees (Manning et al., 1982)[3]. Large portions of the study area are in the high hazard red-attack stage.
The Community of Bear Lake has experienced enormous pine mortality as a result of extensive mountain pine beetle infestation, which has contributed to increased fuel hazard in close proximity to the community. Figure 9 shows the 2006 mountain pine beetle incidence within the study area.
Figure 9. 2006 mountain pine beetle incidence in the study area.
Figure
10 shows a representation of the potential succession of
fire hazard status following beetle attack in a healthy stand. In this diagram,
‘fire hazard’ refers to the potential fire behaviour, regardless of
weather-influenced fuel moisture content. Assessment is based on ph
The healthy stand is represented with 35 to 45% crown closure and has a low fire hazard. The initial phase of pine beetle attack is the death of overstory trees with retained needles and small branches (red-attack and early grey-attack stages). In this phase the standing dead trees input fine fuels to the forest floor (attacked stand) and the stand is a high to extreme fire hazard. The loss of overstory tree foliage increases light levels to the forest floor surface and results in a flush of understory vegetation including new seedlings that regenerate naturally (understory release). This flush depends on a number of factors but is primarily a function of available light, nutrients, moisture and the existing seed bank and plant community. In general, fire hazard is lower during this phase. Over time, seedlings begin to dominate the understory forming a contiguous sapling layer (seedling dominance) and bark begins to slough off the standing dead trees (Seedling Dominance and Bark Sloughing). During this period, hazard is thought to be elevated again due to the input of fine fuels to the forest floor. After this phase, there may be a period of reduced fire hazard before the standing dead timber begins to fall on a large scale. However, once the dead trees fall in large numbers, they create high inputs of surface fuel (represented by the Young Pine Stand with Snags Falling). This is most likely when the stand has reached its highest hazard with the combination of a contiguous fuel load from the surface of the forest floor up and into the overstory canopy. These characteristics yield a stand that is now highly susceptible to stand replacement crown fire.
Figure 10. Diagrammatic representation of fire hazard succession following mountain pine beetle attack. Community Risk Profile
Map
4 shows the probability and consequence of wildfire in
the study area based on the results of the WRMS. Probability of wildfire is
moderate to high in the study area. This result is a function of the predicted
fire behaviour, the history of wildfire in the study area and predicted ability
to suppress fires should they occur. Both the fire history and historic fire
weather suggest that the study area is less prone to wildfire events than some
other ecos
The consequence of wildfire ranges from
moderate to extreme. Proximity to values at risk (e.g., interface) has a large
influence on consequence and Map
4 demonstrates that extreme consequence occurs around
the community of Bear Lake and decreases with distance from built up areas. The
underlying assumption is that consequence of wildfire decreases with fewer
values at risk. Appendix D outlines the Wildfire Risk Management S
6.0
Action
Plan
The Action Plan consists of the key
elements of the Community Wildfire Protection Plan and provides recommendations
addressing each element. As discussed, the key issues focused on for the
protection of
6.1
Vegetation
(Fuel) Management
6.1.1
Objectives
· To remove the majority of identified fuels (dead pine) within the two kilometre protection zone established around the community.
· To proactively lessen potential fire behaviour, thereby increasing the probability of successful suppression and minimizing adverse impact.
· To remove the majority of the hazardous fuel types (C3, C4) within and adjacent to the municipal boundary, over the next year.
6.1.2
Issues
·
The WRMS developed in support
of this plan identified that the core area of
·
There are a number of hazardous
stands of C3 (1,600.8 ha) and C4 (870.1 ha) fuel types in the study area (Table 5 and Map
5). Treatment of other fuel types is not considered
necessary. An example of hazardous fuels in
·
The majority of the area
prioritized for treatment in Map 6 falls on Crown lands and is managed under various forest licenses. Map 7shows the boundaries of various tenures around
Table 5. Fuel type polygons that are a priority for treatment consideration.
|
Fuel
Type |
Polygon
Number |
Area |
Fuel
Type |
Polygon
Number |
Area |
|
C3 |
1 |
10.2 |
C3 |
27 |
290.7 |
|
C3 |
2 |
30.5 |
C3 |
28 |
5.8 |
|
C3 |
3 |
12.2 |
C3 |
29 |
8.7 |
|
C3 |
4 |
49.8 |
C3 |
30 |
38.3 |
|
C3 |
5 |
18.4 |
C3 |
31 |
22.2 |
|
C3 |
6 |
6.2 |
C3 |
32 |
12.8 |
|
C3 |
7 |
31.3 |
C4 |
33 |
2.9 |
|
C3 |
8 |
1.9 |
C4 |
34 |
1.5 |
|
C3 |
9 |
25.4 |
C4 |
35 |
6.8 |
|
C3 |
10 |
374.4 |
C4 |
36 |
20.1 |
|
C3 |
11 |
2.0 |
C4 |
37 |
6.5 |
|
C3 |
12 |
7.0 |
C4 |
38 |
31.6 |
|
C3 |
13 |
4.0 |
C4 |
39 |
0.8 |
|
C3 |
14 |
20.0 |
C4 |
40 |
15.4 |
|
C3 |
15 |
2.4 |
C4 |
41 |
162.4 |
|
C3 |
16 |
100.6 |
C4 |
42 |
3.2 |
|
C3 |
17 |
187.5 |
C4 |
43 |
10.2 |
|
C3 |
18 |
13.6 |
C4 |
44 |
3.0 |
|
C3 |
19 |
9.6 |
C4 |
45 |
38.3 |
|
C3 |
20 |
65.5 |
C4 |
46 |
4.6 |
|
C3 |
21 |
20.4 |
C4 |
47 |
18.0 |
|
C3 |
22 |
3.1 |
C4 |
48 |
75.8 |
|
C3 |
23 |
31.4 |
C4 |
49 |
119.3 |
|
C3 |
24 |
10.4 |
C4 |
50 |
3.7 |
|
C3 |
25 |
6.6 |
C4 |
51 |
345.9 |
|
C3 |
26 |
177.9 |
Total C3 Fuels: |
1,600.80 |
|
|
|
|
|
Total C4 Fuels: |
870.1 |
|
Figure 11. Example of a C4 fuel type in the community.
6.1.3
Recommendations
Recommendation 1:
The RDFFG and the community of
Recommendation 2:
The RDFFG and the community
of
Recommendation 3: A qualified professional forester (RPF), with a sound understanding of fire behaviour and fire suppression, should develop treatment prescriptions. Any treatments that take place on sloped sites must be prescribed with consideration given to slope stability. Where slope stability may be an issue, a Professional Geotechnical Engineer should review the treatment prescription.
Recommendation
4: Fuel treatment strategies should
target the removal of dead lodgepole pine and the retention of remaining live
structure including lodgepole pine that is <15 cm in diameter.
Recommendation
5: FireSmart priority 1 (10 m) and priority 2 (30m) zones should be
used when developing fuel treatment prescriptions adjacent to structures.
Priority 1 zones should be free of fuels. In priority 2 zones stocking should
be maintained below 400 stems per hectare and provisions for maintenance (e.g.,
stocking surveys) should be included in treatment prescriptions.
6.1.4 Time-line for Implementation
6.2
Communication
and Education
6.2.1
Objectives
· To raise the awareness of elected officials as to the resources required and the risk that wildfire poses to communities.
· To make residents and businesses aware that their communities are interface communities and to educate them about the associated risks.
· To work diligently to reduce ignitions during periods of high fire danger.
· To improve the availability of information on fire protection and FireSmart principles on the RDFFG web site.
· To improve fire danger and evacuation signage in the next two years.
6.2.2
Issues
· Currently there is no information available on the RDFFG website related to fire protection and the FireSmart Manual. It would be beneficial to add information on what individual homeowners can do to protect their homes as well as information on up-to-date fire danger and fire restrictions.
· Currently there is limited fire danger signage within the community.
6.2.3
Recommendations
Recommendation 6: Given the mountain pine beetle outbreak and the significant fire risk that communities will face over the next 25 years, the RDFFG must consider enhancing their existing website to outline fire risks, current fire danger and proactive steps individual homeowners can take to make their homes safer within the region. Other information, such as fire danger and FireSmart principles, should be maintained on the regional site
Recommendation 7:
Signage consisting of current fire danger, campfire bans and general warnings
regarding fire safety should be posted at the major entrances to
Recommendation 8:
Given that the mountain
pine beetle has caused high levels of mortality across the region, the RDFFG
should consider conducting a larger scale risk assessment and CWPP process for
unincorporated communities. A Regional District CWPP would be more cost- and
time- effective than completing individual plans for each unincorporated
community.
6.3
Structure
Protection
6.3.1
Objectives
· To adopt a FireSmart approach to site and structure hazard assessment and structure protection.
6.3.2
Issues
· While most homes were built with rated roofing material, a number of homes do not meet the FireSmart structure hazard standards for interface fire safety.
· Combustible materials stored within 10 m of residences are considered a significant issue. Woodpiles or other flammable materials adjacent to the home provide fuel and ignitable surfaces for embers.
· Defensible space around homes does not always meet a FireSmart standard.
Figure 12. Example of home with an open deck.
Figure 13. Example of home with inadequate setback to forest vegetation.
6.3.3
Recommendations
Recommendation 9:
The RDFFG should investigate the policy tools available for reducing
wildfire risk within
Recommendation 10:
Some homes are built
immediately adjacent to the forest edge with trees and vegetation in direct contact
with homes. The RDFFG should incorporate building setbacks into bylaw with a
minimum distance of 10 m when buildings border the forest interface.
Recommendation 11:
Given the wildfire risk
profile of
6.4
Emergency
Response
6.4.1 Objectives
·
To ensure
effective evacuation and fire suppression capability.
6.4.2 Issues
· The RDFFG has an emergency response and recovery plan in place that deals with wildfire events (http://www.rdffg.bc.ca/Services/Public_safety/RDERRP.pdf). Given the size of the community, access for evacuation and emergency response within the developed area is not considered an issue that requires action beyond the RDFFG plan at this time.
·
The
6.4.3 Recommendations
Recommendation 12:
The community of
6.5
Training
6.5.1
Objectives
· To ensure adequate and consistent training for firefighter volunteers and to build firefighter experience.
· To train all Fire Department volunteers to the Provincial standard (S100 and S215) on an annual basis.