District of Maple Ridge   Community Wildfire Protection Plan Considerations for Wildland Urban Interface Management in the District of Maple Ridge, British Columbia   Submitted by: B.A. Blackwell and Associates Ltd. 3087 Hoskins Road North Vancouver, B.C. V7J 3B5   Submitted to: Peter Grootendorst, Chief Director of Operations and Staff Development District of Maple Ridge Fire Department 22703 Dewdney Trunk Rd. Maple Ridge, B.C. V2X 3K3

 

RPF PRINTED NAME		Registered Professional Foresters Signature and Seal
Bruce A. Blackwell	RPF 2073
DATE SIGNED
I certify that I have reviewed this document and I have determined that this work has been done to standards acceptable of a Registered Professional Forester.

Executive Summary

The District of Maple Ridge (hereinafter referred to as ‘the District’) is embedded within the forest; approximately 60% of the community is forested. This region of the Province is susceptible to both lightning and human caused fires. Overall, the community could be classified with a fire risk profile described by a low to moderate fire probability and high to extreme consequence based on the values at risk.

B.A. Blackwell and Associates Ltd. were retained to develop a Community Wildfire Protection Plan in consultation with District staff from the Fire Rescue Service and other support staff as required. The project was funded by the District and a supplementary grant from the Union of B.C. Municipalities.

The key priorities for wildfire management planning in the District were identified as:

·         Hazard and risk mapping of the District to establish areas of the community that are at greatest risk from fire;

·         Facilitation of communication and education to local residents, all levels of government, and the general public;

·         Facilitation of a review and amendment of existing and proposed Development Permits based on the hazard mapping assessment;

·         Facilitation of revisions to building standards and bylaws; and

·         Identification of potential locations for strategic fuel breaks and forest stand-level fuel reduction both within and outside the community.

A Wildfire Risk Management System (WRMS) was developed to identify key areas of risk within the community and to support the development of the Plan. A synopsis of key findings and plan recommendations follows. In total, 19 recommendations were developed for consideration by the District. These focus on Communication and Education, Structure Protection, Emergency Response, Training and Post Fire Rehabilitation.

Synopsis of Key Findings

Risk Assessment

The fire risk analysis of probability and consequence indicates that, under high to extreme fire weather conditions, significant areas of the District are vulnerable to wildfire.

While much of the study area has a low to moderate fire probability, the consequence of fire defined by the values at risk is considered high. The highest probability fire scenario is a fire started from human ignition within the community that spreads out into the surrounding forest.

Under high to extreme fire weather conditions, spotting of burning embers was modeled within and adjacent to the Municipality. The model results indicate that, under extreme fire weather conditions, substantial areas of the community would be vulnerable to spotting at wind speeds averaging 9 kilometres per hour or greater. 

Significant portions of the community are immediately adjacent to the forest interface and many of the bordering fuel types are considered high hazard given their spotting and fire behaviour potential.

Education and Communication

The Maple Ridge Fire Rescue Service has been actively working on interface fire related communication and education. Public interest, participation and awareness have been limited within the community. More work is required to engage the community in this issue if successful planning, preparation and risk reduction measures are to be achieved.

Structure Protection

The current building code and District bylaws allow for the development of a community that is vulnerable to a large interface fire event. Both the building standards and the materials used on many structures increase fire risk from an ember shower associated with spotting from a large fire event. Many of the homes and businesses in the District would fail a FireSmart Assessment (the new Provincial planning standard for interface communities). Given the extensive nature of the problem and the significant costs involved, this is an issue that cannot easily be rectified in the short term.

Emergency Response

While much of the urban interface within the District is accessible, a number of areas are considered isolated because of one-way access in and out. In a number of areas within the District, emergency access for the purposes of fire protection is considered a serious problem.

The fire risk assessment indicates that the areas most vulnerable to smoke are the lower elevation areas within the Fraser Valley. Heavy smoke pooling in the valley bottom will require evacuation of the community and may cripple emergency response given that both the Public Safety Building (fire hall) and Health Care Centre are located within the area vulnerable to smoke. Given the generally poor air quality within the GVRD during summer months a large interface fire within Maple Ridge has the potential to cause serious air quality problems throughout the region.

Training

Over the past several years, Maple Ridge Fire Rescue Service has undertaken extensive training to deal with interface fires. The current level of training and available equipment related to interface fire response is considered adequate but, given the risk of fire to the community, an advanced program that fosters continuous improvement and skill renewal would be beneficial.

Fuel Management

The WRMS identified areas of high hazard fuels associated with values at risk within the District. The size and scale of these areas are considered a significant management challenge. The only meaningful way to address the identified fuels problem in the short-term is to utilize existing breaks (roads, railways, and deciduous forest cover) in combination with aggressive emergency response and initial attack. Consideration should be given to protecting the broader landscape with fuel breaks that isolate fuels into compartments, improve suppression capability and slow or limit rates of spread. Attention should be given to advanced fuels management planning associated with University of British Columbia Research Forest due to industrial harvesting activities that occur on the site and its history of human caused ignitions. In addition, there are high infrastructure values associated with the research investment in the forest. BC Parks land and other managed Crown land adjacent to the District should also be considered in advanced fuels management planning. Golden Ears Provincial Park in particular is a high-use area with a history of human caused fires that should also be considered.

Post Fire Rehabilitation

An extensive fire within the District could have serious and long lasting consequences that include impacts on visual and water quality, recreation and sensitive resource values, and could create environmental hazards. Additionally, there could be significant economic losses associated with loss of tourism and overall business revenue. Prompt rehabilitation efforts to restore and green-up burn areas are considered important and should be addressed through a comprehensive post rehabilitation planning exercise.

Recommendations

Communication and Education

 

 

Structure Protection

 

 

 

Emergency Response

 

 

 

 

Training

Fuel Management

 

 

 

 

 

Post Fire Rehabilitation

Table of Contents

1.0        Introduction... 1

1.1        Background.. 1

1.2        Purpose and Scope. 1

2.0        District of Maple Ridge.. 2

2.1        Study Area. 2

2.2        Population.. 4

2.3        Economy. 4

2.4        Infrastructure. 6

3.0        Fire Environment.. 6

3.1        Fire Weather. 6

3.2        Fuels. 9

3.2.1     Fuel Type Summary. 11

3.2.2     Fuel Type Descriptions. 12

3.3        Topography. 19

3.4        Historic Ignitions. 20

4.0        Wildland Urban Interface Defined.. 22

4.1        Vulnerability of the Wildland Urban Interface to Fire. 24

5.0        Wildland Urban Interface Continuum... 25

5.1        Communication and Education.. 26

5.2        Structure Protection.. 27

5.3        Emergency Response. 27

5.4        Training. 28

5.5        Vegetation Management 28

5.6        Post Fire Response – Rehabilitation.. 28

6.0        Communication and Education... 29

6.1        Communication and Education Goals. 29

6.2        Target Audiences. 29

6.3        Pilot Projects. 30

6.4        Communication Plan.. 30

6.5        Website. 31

6.6        Media Contacts, Use and Coordination.. 31

6.7        Other Methods. 31

6.7.1     Homeowners. 32

6.7.2     Government Ministries, District and Municipal Officials, Disaster Planning Services, Utilities  32

6.8        General Messages. 32

7.0        Structure Protection... 33

7.1        FireSmart 33

7.1.1     Roofing Material 33

7.1.2     Building Exterior - Siding Material 36

7.1.3     Balconies and Decking. 36

7.1.4     Combustible Materials. 36

7.2        Planning. 37

7.3        Bylaws. 37

7.4        Sprinklers. 38

7.5        Joint District Cooperation.. 38

7.6        Structured FireSmart Assessments of High Risk Areas. 39

8.0        Emergency Response.. 39

8.1        Access and Evacuation.. 39

8.2        Fire Response. 41

9.0        Training Needs. 42

10.0      Vegetation (Fuel) Management.. 43

10.1      Principles of Fuel Management 43

10.1.1    Definition.. 43

10.1.2    Purpose. 43

10.1.3    Forest Fuels. 44

10.1.4    Surface Fuels. 44

10.1.5    Aerial Fuels. 45

10.2      Fuel Treatment Needs. 47

10.2.1    The Principles of Landscape Fuelbreak Design.. 51

10.2.2    Existing Landscape Fuelbreaks Within the District 58

10.2.3    Proposed Landscape Fuelbreaks within the District 60

10.3      Maintenance. 62

11.0      Post Wildfire Rehabilitation Planning.. 62

12.0      References. 65

 

 

List of Figures

Figure 1. Map showing the study area covered by this plan, the District boundary and land ownership categories. 3

Figure 2. Seasonal variability (April-October) in the number of Danger Class IV and V-days within the study area as described by the regional climate of the CWHdm. 8

Figure 3. Summary of seasonal (April-October) high and low drought codes by year in the CWHdm within the District. 9

Figure 4. Comparison of original MOF fuel typing (top) and updated fuel typing (bottom) for the District. 10

Figure 5. Example of a high-density pole sapling western hemlock-amabilis fir stand – classified as a C2 fuel type. 12

Figure 6. Example of evenly stocked, moderate density second growth stand – classified as a C3 fuel type. 13

Figure 7. Example of a moderate to high-density second growth stand of hemlock and Douglas-fir classified as a C4 fuel type. 14

Figure 8. Example of young forest of Douglas fir, western hemlock and western red cedar – classified as a C5 fuel type. 15

Figure 10. Moist rich site dominated by red alder – classified as a D1 fuel type. 17

Figure 11. Moist-fresh, rich site of mixed Douglas-fir and deciduous – classified as M2 fuel type. 18

Figure 12. View of topographic relief of the District looking north (sourced from Google EarthTM, 2006). 20

Figure 13. A spatial summary of human and lightning caused fire ignitions within the District (1950 to present). 22

Figure 14. Wildland urban interface defined by red border where the forest meets the community. 23

Figure 15. Graphical example showing variation in the definition of interface. 24

Figure 16. Firebrand caused ignitions: burning embers are carried ahead of the fire front and alight on vulnerable building surfaces. 25

Figure 17. Radiant heat and flame contact allows fire to spread from vegetation to structure or from structure to structure. 25

Figure 18. Wildland urban interface continuum. 26

Figure 19. Photograph showing unrated roofing material present on many homes within the District wildland urban interface. 35

Figure 20. Example of home with wood siding and open decks and balconies. 36

Figure 21. Overview of access routes in the District – Note: yellow highlights indicate neighbourhoods or portions of the District with poor access and evacuation routes. 40

Figure 22. High surface fuel loading under a forest canopy. 45

Figure 23. Comparisons showing stand level differences in the height to live crown. 46

Figure 24. Comparisons showing stand level differences in crown closure. 46

Figure 25. Comparisons showing stand level differences in density and mortality. 46

Figure 26. Overview of high priority fuel types within the District that pose a spotting and interface fire risk. 48

Figure 27. High Vulnerability Interface Areas. 49

Figure 28. Schematic showing the principles of thinning to reduce stand level hazard. 51

Figure 29. Final overlay of probability and consequence from the Wildfire Risk Management System. 52

Figure 30. Conceptual diagram of a shaded fuelbreak pre treatment and post treatment. 53

Figure 31. 1994 Tyee Fire shaded fuelbreak example. 58

Figure 32. Overview of the BCTC rights-of-way, highways, railways and deciduous fuel types that serve as existing fuelbreaks within the District. 59

 

1.0                           Introduction

1.1                             Background

In 2005 B.A. Blackwell and Associates Ltd. were retained to assist the District of Maple Ridge in developing a Community Wildfire Protection Plan, hereinafter referred to as “the Plan”. ‘FireSmart – Protecting Your Community from Wildfire’ (Partners in Protection 2004) was used to guide the protection planning process. Within the municipality, the assessment considered important elements of community wildfire protection that included communication and education, structure protection, training, emergency response, and vegetation management.

The social, economic and environmental losses associated with the 2003 fire season emphasized the need for greater consideration and due diligence in regard to fire risk in the wildland urban interface (WUI). In considering wildfire risk in the 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. While the probability of fire in coastal communities is substantially lower when compared to the interior of British Columbia, the consequences of a large fire are likely to be very significant in lower mainland interface communities given population size, values at risk, and environmental considerations.

The results of this study will provide the District with a framework that can be used to review and assess areas of identified high fire risk. Additionally, the information contained in this report should help to guide the development of emergency plans, emergency response, communication and education programs, bylaw development in areas of fire risk, and the management of forest lands adjacent to the municipality.

1.2                             Purpose and Scope

The Plan was initiated by Maple Ridge Fire Rescue Service and was jointly funded by the District of Maple Ridge and the Union of B.C. Municipalities. The purpose of the Plan is to quantify and identify fire risk within the community, develop plans and management actions that can be undertaken to minimize the risk, and provide a tool to communicate and educate the residents and visitors in Maple Ridge about fire risk and management issues.

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 estimation of spotting risk.

·         Phase III – Development of the Plan, which outlines measures to mitigate the identified risk through structure protection, emergency response, training, communication, and education.

 

2.0                           District of Maple Ridge

2.1                             Study Area

The District of Maple Ridge is situated on the north side of the Fraser River in the Fraser Valley and is 28,675 ha in size. The District is approximately 45 km east of Vancouver. Figure 1 outlines the boundary of the District, and land ownership within the area encompassed by this plan. The ownership information is based on a 1997 inventory and information provided by the District. The 1997 inventory has likely changed over the years and the entire area was not covered by the District’s ownership information, therefore, there may be some inaccuracies in the data presented in Figure 1. The total study area that makes up this plan includes map sheet numbers 092G.017, 092G.018, 092G.019, 092G.027, 092G.028, 092G.029, 092G.037, 092G.038, 092G.039. The total study area is 73,525 hectares.

Figure 1. Map showing the study area covered by this plan, the District boundary and land ownership categories.

2.2                             Population

The District had an estimated population of 65,000 people in 2000 and has one of the fastest population growth rates in BC[1].

2.3                             Economy

The economy of Maple Ridge is primarily dependent on agriculture, fisheries, forestry and mining. Secondary industries include retail, commercial and care services. Approximately 65% of residents commute to work outside the district. Table 1 and
Table 2 list the major employers in the District.

Table 1. Major private sector employers as of 2000[2]

 

Table 2. Major public sector employers as of 2000[3]

 

2.4                             Infrastructure

The local Fire Department, Emergency Social Services and Ridge Meadows Hospital and Health Care Centre are critical to emergency response service in the community. However, in the event of a localized emergency within the District of Maple Ridge, adjacent municipalities with health care and emergency response facilities may also be able to provide rapid emergency response. These facilities provide the foundation for incident command and response during a large fire event and therefore must be prepared to deal with large and complex situations.

Emergency response is dependent on electrical and water service within the community in the event of a large-scale emergency. The community is dependent on surface water from a series of surrounding forested watersheds. Any disturbances (human and/or natural) within these watersheds have the potential to impact the supply of drinking water to the community.

Electrical service to the community comes from a network of transmission infrastructure that runs in an east-west direction through the southern half of the District. A large fire has the potential to impact this service by causing a disruption in network distribution through direct or indirect means. For example, heat from the flames or fallen trees associated with a fire event may cause power outages. Consideration must be given to protecting this critical service and providing power back up at key facilities to ensure that the emergency response functions are reliable.

The key infrastructure discussed above was considered as part of the Wildfire Risk Management System. The results of this analysis indicate that consideration must be given to protection of the critical infrastructure identified above.

3.0                           Fire Environment

3.1                             Fire Weather

The Canadian Forest Fire Danger Rating System (CFFDRS), developed by the Canadian Forestry Service, is used to assess fire danger and potential fire behaviour. The Ministry of Forests and Range (MOFR) maintains a network of fire weather stations during the fire season that is used to determine fire danger on forestlands within the District. Similarly, other lower mainland communities monitor fire weather information provided by the MOFR Protection Branch to determine hazard ratings and associated fire bans and closures within their respective municipalities.

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 District can vary from season to season. The District is defined by the regional climate of the Coastal Western Hemlock dry maritime (CWHdm), very dry maritime (CWHxm1, CWHxm2), submontane very wet maritime (CWHvm1), montane very wet maritime (CWHvm2) and Mountain Hemlock windward moist maritime (MHmm1) biogeoclimatic units.

Table 3. BEC Area Summary

BEC Unit	% of Total Study Area	Area within Total Study Area (ha)	% of District of Maple Ridge	Area within District of Maple Ridge (ha)
CWHdm	32	23,761	52	14,937
CWHvm1	6	4,528	5	1,309
CWHvm2	10	7,221	16	4,586
CWHxm1	2	1,317	3	917
MHmm1	3	2,045	2	564
Nonfuel/No Data	47	34,653	22	6,362
Total	100	73,525	100	28,675

 

Fire danger within the District can vary significantly from season to season. Figure 2 is a compilation of available weather station data within the CWHdm biogeoclimatic unit (representative of the District) that dates back to 1875 and provides a summary of the total number of Danger Class IV and V-days from April through to October for each year. This compilation shows that, within any given year, the fire danger can fluctuate substantially from fewer than 20 days to over 70 days. On average, the number of Danger Class IV and V-days within the CWHdm is 46 per year. Typically, the most extreme fire weather occurs between the middle of July and the third week of August. When compared to other regional climates of the coast, such as the Coastal Western Hemlock very dry maritime biogeoclimatic unit (CWH xm1 - east coast of Vancouver Island) and Coastal Douglas Fir biogeoclimatic unit (CDF - Southern Vancouver Island and Gulf Islands), the Lower Mainland is not as dry.

Figure 2. Seasonal variability (April-October) in the number of Danger Class IV and V-days within the study area as described by the regional climate of the CWHdm.

A summary of historic drought codes provides a similar comparison to danger class days and reinforces the point that the District experiences extended periods of summer drought (Figure 3). A drought code that exceeds 500 is considered high and is associated with extreme fire behaviour.

Figure 3. Summary of seasonal (April-October) high and low drought codes by year in the CWHdm within the District.

The results of the weather data analysis show that, historically, there have been a number of years when fire danger in the District has been high or extreme for an extended period during the summer months. Complacency is an inappropriate response to fire risk. Management responses, in terms of fire prevention, mitigation and response, should be adjusted in accordance with the level of risk.

3.2                             Fuels

Fuel classification was based on the CFFDRS and a summary of fuel type attributes collected in the field. Typically, the CFFDRS fuel types only adequately describe the variation in fuels present in the District. In a number of areas, the classification was not correct. This was primarily a function of large areas of forest being classified as D1 when, in fact, they were better represented by another CFFDRS fuel type (Figure 4). For each type identified, we have attempted a best approximation of the CFFDRS classification and have supported this classification with a summary of detailed attributes. The updated Ministry of Forests and Range fuel typing was improved upon and adjusted to incorporate local variation. 

Figure 4. Comparison of original MOF fuel typing (top) and updated fuel typing (bottom) for the District.

3.2.1                       Fuel Type Summary

Table 4. Percentages of each fuel type within each BEC unit based on the total study area

	C2%	C3%	C4%	C5%	C7%	D1%	M2%	M2c%	01a%	01b%	% Total
CWHdm	1	25	2	15	1	32	1	8	15	0	100
CWHvm1	0	48	6	34	1	7	1	2	0	0	100
CWHvm2	4	19	17	49	1	3	7	0	0	0	100
CWHxm1	0	0	0	0	0	52	0	9	0	39	100
MHmm1	0	1	4	77	3	4	11	0	0	0	100

 

Table 5. Summary of fuel types based on the total study area

	C2	C3	C4	C5	C7	D1	M2	M2c	01a	01b	Non-Fuel/No Data	Total
Area (ha)	495	9,445	2,030	10,152	412	8,849	1,057	2,252	3,658	522	34,653	73,525
% Total	1	13	3	14	1	12	1	3	5	1	47	100

 

3.2.2                       Fuel Type Descriptions

The following is a general description of the dominant fuel types within the District of Maple Ridge

C2 fuel type

Area of Fuel Type (ha)	495
Structure Classification	Pole sapling
Dominant Tree Species	Tsuga heterophylla  (western hemlock), Psuedotsuga menziesii (Douglas-fir), Chamaecyparis nootkatensis (Yellow Cedar), Thuja Plicata (western redcedar) and Abies amabilis (amabilis fir)
Understory Vegetation	Sparse – None (< 5% cover)
Average Age	30 yrs
Average Height	10 – 15 m
Stand Density	1,500 – 3,500 stems/ha
Crown Closure	70 – 80%
Height to Live Crown	Average 3 m
Surface Fuel Loading	< 3 kg/m2
Burn Difficulty	Moderate to high; however, if fire is wind driven then there is a high potential for extreme fire behaviour and active crown fire.

Table 6. Estimated fire behaviour in C2 fuel types by BEC assuming 90^th percentile weather conditions, 9 km windspeeds and flat terrain.

Fuel Type	BEC	Rate of Spread (km/h)	Head Fire Intensity (kW/m)	Crown Fraction Burned	Ignition Potential	Flame Height (m)	Crown Base Height (m)	Area (ha)
C2	CWHdm	14	18,648	95%	99 %	7	3	202
C2	CWHvm2	8	8,226	80%	81 %	5	3	293

Figure 5. Example of a high-density pole sapling western hemlock-amabilis fir stand – classified as a C2 fuel type.

C3 fuel type

Area of Fuel Type (ha)	9,445
Structure Classification	Pole sapling to young forest
Dominant Tree Species	Psuedotsuga menziesii (Douglas-fir), Tsuga heterophylla  (western hemlock), Thuja plicata (western redcedar) and Abies amabilis (amabilis fir)
Understory Vegetation	Low (< 35% cover)
Average Age	50 – 60 yrs
Average Height	20 – 30 m
Stand Density	1,000 – 1,200 stems/ha
Crown Closure	65 – 70 %
Height to Live Crown	Average 8 m
Surface Fuel Loading	< 5 kg/m2
Burn Difficulty	Moderate; however, if fire is wind driven then there is a high potential for extreme fire behaviour and active crown fire.

Table 7. Estimated fire behaviour in C3 fuel types by BEC assuming 90^th percentile weather conditions, 9 km windspeeds and flat terrain.

Fuel Type	BEC	Rate of Spread (km/h)	Head Fire Intensity (kW/m)	Crown Fraction Burned	Ignition Potential	Flame Height (m)	Crown Base Height (m)	Area (ha)
C3	CWHdm	5	5,186	6%	91 %	4	8	5,851
C3	CWHvm1	4	3,108	0%	85 %	3	8	2,196
C3	CWHvm2	2	1,237	0%	82 %	2	8	1,376
C3	MHmm1	2	913	0%	71 %	2	8	25

Figure 6. Example of evenly stocked, moderate density second growth stand – classified as a C3 fuel type.

 C4 fuel type

Area of Fuel Type (ha)	2,030
Structure Classification	Pole sapling
Dominant Tree Species	Pinus contorta (lodgepole pine), Psuedotsuga menziesii (Douglas-fir), Tsuga heterophylla  (western hemlock), Thuja plicata (western redcedar) and Abies amabilis (amabilis fir)
Understory Vegetation	Low (< 25% cover)
Average Age	24 –30 yrs
Average Height	16 m
Stand Density	1,000 – 1,500 stems/ha
Crown Closure	45 – 65 %
Height to Live Crown	Average 4 m
Surface Fuel Loading	< 5 kg/m2
Burn Difficulty	Moderate to high; however, if fire is wind driven then there is a high potential for extreme fire behaviour and active crown fire.

Table 8. Estimated fire behaviour in C4 fuel types by BEC assuming 90^th percentile weather conditions, 9 km windspeeds and flat terrain.

Fuel Type	BEC	Rate of Spread (km/h)	Head Fire Intensity (kW/m)	Crown Fraction Burned	Ignition Potential	Flame Height (m)	Crown Base Height (m)	Area (ha)
C4	CWHdm	14	19,277	94%	100 %	7	4