Learning from Wildland/Urban Interface Fire Disasters: The Case for Risk Mitigation

Transcription

1 2017 AEMA Stakeholder Summit Learning from Wildland/Urban Interface Fire Disasters: The Case for Risk Mitigation Presented by: Alan Westhaver M.Sc. Fernie, British Columbia Study Sponsored by: The

2 A lot has changed in 108 years Fernie, BC 2016 Fort McMurray, AB but outcomes are strikingly similar! Technology Equipment Construction Science Fire fighting capability Response times Building codes and materials Knowledge of fire behavior

3 To achieve a better outcome, we must change our approach Will the Fort McMurray disaster of 2016, or the summer of 2017 in south/central BC, be the trigger for fundamental changes? To many other parts throughout the province, Fernie will contain a lesson in this respect. - Wm. Fernie 1908

4 Study sponsor: : What: An independent centre founded by the insurance industry Mandate: To address increasing losses from natural disasters Basic Premise: Many disaster losses are preventable Promote: Disaster prevention research and communication Wildland/Urban Interface Fire: One of several featured perils 20

5 Presentation objectives: 1. Highlight: Key lessons learned from WUI fire disasters 2. Present: Findings of my post-disaster investigations (2) 3. Make a case: For more effective risk mitigation vs. response 4. Challenge EMA s: To become more active in wildfire loss reduction.

6 What is the Wildland/Urban Interface? The presence of structures in locations where conditions result in the potential for their ignition from flames and firebrands* of a wildland fire. * A.K.A. embers Where forest meets homes? WUI

7 A wildland fire becomes a wildland/ urban interface fire when. the fuel being consumed by fire begins to include structural fuel + = wildland/urban interface fire

8 When do WUI fires occur? Almost anytime of the year Whenever fuel dries out (high wind, low humidity) Sooner and later; as fire seasons extend under climate warming.

9 Are WUI fires a new issue? 1825: Miramichi, NB. 1871: Peshtigo, WI. 1908: Fernie, BC. 1916: Matheson Disaster, ON. 1991: Oakland, CA. 160 fatalities 1,300 dead, 518,000 ha. 5,000 homeless, 9 + killed 400 dead 2,249 homes; 790 in 1 hour

10 Lessons learned No fire suppression system in the world can stop losses from large conflagrations. The outcome depends on risk mitigations taken before the fire, on our property! More fire trucks are not the answer. this is!

11 Lessons learned Embers ignite more than 50% of the homes destroyed by wildfires, even 80 90% Burn Holes in Canopy of Porch Glider Ft. McMurray Most of the time It s not the BIG flames Or radiant heat that trigger home ignition

12 There is no Silver Bullet WUI fires are a complex problem Multi-disciplinary Trans-jurisdictional Geographically variable Private and public lands Varied land ownership Highly dynamic events Wide range of fuels We must work together, closely and pro-actively!

13 So, what s our best answer? FireSmart: 7 Disciplines of Wildfire Risk Mitigation: 1. Vegetation Management 2. Public Education/ Communication 3. Legislation & Regulations 4. Development/ Building 5. Planning 6. Training 7. Interagency Cooperation * Based on NFPA standards.

14 Lessons learned How do we know risk mitigation works? Incidental observations dating back decades Ignition modelling and fire engineering experiments Experimental high intensity forest fires (NWT, AB) IBHS Fire Dragon & NIST testing facilites, USA * 85 to 90% of homes without flammable roofs and 10m of clearance will survive a wildfire

15 Lessons learned Small actions, make a BIG difference Most risk mitigations around homes are: o Inexpensive o Easily accomplished o Not very time consuming o More like, organized puttering WUI residents are not helpless victims Find and eliminate Fire Pathways

16 But, FireSmart measures don t work if they are not applied Social science tells us why people choose NOT to adopt FireSmart practices: 1. Information alone doesn t change behavior, understanding does! 2. Feeling helpless against monster fire where do we begin? 3. FireSmart is ugly, forest health more important than fire risk. 4. Believe it s too expensive, too difficult. 5. Lack of trust in local authorities.

17 What s in the future? 3 converging trends Climate Warming Increased: fire danger/ # fires/ fire intensity/ area burned More Development in WUI Areas Lack of Wildfire Risk Mitigations Response Frequently Overwhelmed Forest Health Issues = rising fuel loads WUI Disaster

18 How do WUI Fire disasters develop? Slave Lake, AB May 21, 2011 Institute for Catastrophic Loss Reducti

19 CONSEQUENCES CONDITIONS Wildland/Urban Interface Disaster Sequence * Severe Fire Conditions Fuel, Weather, and Topography Wildland Fire Rapid fire spread and/or high fire intensity Urban Fire Multiple highly ignitable homes exposed flame + embers Firefighting Resources Overwhelmed By wildfire and burning homes Firefighting Effectiveness Reduced or Non-existent home-to-home spread DISASTER! Many homes destroyed * Calkin et al. (2014)

20 We must address the root issue: 1. Homes that are highly susceptible to ignition during a wildfire event, mostly by embers 2. Combustible materials within 30m of the home, and that can carry fire to the home. If homes do not ignite, they cannot burn.. If homes do not burn, then disaster is avoided - Jack Cohen US Forest Service Scientist ForestWise Environmental Consulting Ltd.

21 Identify and mitigate risks at home and in our back yards Hazard Factors (Categories) 1. Structural 2. Ignition sites 3. Vegetation 4. Topography ForestWise Environmental Consulting Ltd

22 Structural hazard factors Top to bottom: 1. Roof 2. Vents and openings 3. Exterior walls 4. Windows and glazing

23 Ignition site hazard factors Miscellaneous Combustibles: 1. Roof cleanliness 2. Balconies, decks, porches 3. Nearby combustibles (fences, trash, firewood, ATVs, others) 4. Ember accumulators: Inside corners Base of walls Wood chip mulch beds Eddies, dead zones Nooks and crannies

24 Vegetation/fuel hazard factors* Hazard is evaluated according to: How much? How combustible? (evergreen vs. deciduous) How close to the home is it? How continuous is it? o Horizontally o Vertically * Includes landscaped and native plants

25 Why some homes survived: Learning from the Fort McMurray wildfire disaster Alan Westhaver, M.Sc.

26 Study question: Why did some homes survive with little or no damage, while others did not? Led to many other questions: o How did fire spread towards homes? o How did this WUI disaster evolve? o How did homes ignite? o Where did homes survive? o Does FireSmart work?

27 Methods: Home hazard assessment Existing FireSmart home hazard assessment system (2003) Modified to reflect recent knowledge of of embers as significant ignition sources Based on NFPA standards Used retrospectively on homes destroyed by fire o Unique application o Deductive skills o What burned, and what did not!

28 Methods: Office confirmation Regional Municipality of Wood Buffalo Mapping Tool Before After

29 Study area Homes subject to flames, radiant heat, and embers Places where the wildland fire transitioned from forest fuel to urban fuel Near edges of urban neighbourhoods (Abasand, Beacon Hill, Wood Buffalo) Saprae Creek Estates acreages Avoided structure - to - structure fire zone o Clues obliterated by debris

30 Primary study area Side-by-side (unburned, burned) Similar exposure to fire and heat Similar construction, age, style Urban and rural

31 Other study cases Urban neighbourhoods exposed to extreme heat, and superabundant embers But individual or groups of homes did not ignite

32 Other study cases Isolated homes that ignited and burned well within otherwise undamaged neighbourhoods

33 Other study cases Isolated urban homes that survived amid neighbourhoods that were destroyed.

34 Study limitations - Sample size limited to ~85 detailed home evaluations - Post-fire observations only - What did not burn and where; clues in the ashes - Inability to view some risk factors - (e.g. roof cleanliness)

35 Conclusions: Fort McMurray Investigation

36 Overall Results of the Fort McMurray investigation echo results of previous U.S. and Canadian studies 36

37 Conclusion: Home survival and vulnerability 1. Surviving homes (or groups of homes) and surrounding ignition zones were significantly less vulnerable to ember ignition than homes that were destroyed; low in rated hazard factors. o o o In all Study Cases Across all types of analysis In urban and country residential areas Adoption of FireSmart practices by homeowners was strongly correlated to home survival.

38 Conclusion: Home survival and vulnerability 1a. Anomalies mostly explained by peculiarities in hazard assessment system: Overestimates hazard vegetation > 30m from home Not all critical weaknesses are rated (i.e. Achilles Heel)

39 Conclusion: Effectiveness of FireSmart risk mitigations 2. Beyond doubt, recommended FireSmart Guidelines demonstrated their effectiveness; survival is not random. o o o 81% of all surviving homes assessed were rated as FireSmart ; ¾ of them in the Low hazard category. Matched pairs: 94% of the time, the surviving home was rated with lower hazard than burned home - by 30+ points. All miracle homes rated low hazard.

40 Conclusion: Cause of home ignitions 3. At the urban margins, embers ignited the vast majority of homes destroyed in Fort McMurray neighbourhoods during early stages of the disaster. o o With few exceptions, clearances were adequate* to prevent home ignition from radiant heat. In almost all cases, buffers were adequate* to protect homes from ignition by direct contact with forest flames. * See results of experimental crown fires (Cohen and others).

41 Good news! New homes are inherently more FireSmart! Building Materials: Virtually no combustible roofs (untreated wooden shakes) Popularity of fire resistant siding; brick, stone, masonry, stucco feature walls, cement composition siding Double-pane + windows, well-built vinyl, metal clad Building Features: Very few exterior openings and vents Fire-resistant deck supports High proportion of stone, concrete, closed-in front entrances

42 Conclusion: The WUI disaster sequence 4. The Fort McMurray disaster followed a well known pattern. 4a. This pattern was replicated independently in several different neighbourhoods*: o o o Beacon Hill Abasand Heights Wood Buffalo * Recorded on YouTube

43 Conclusion: The WUI disaster sequence 5. Breaking the disaster sequence at its weakest point by addressing home vulnerability to ember ignition (i.e. root cause) would be the most effective solution. Urban Conflagration

44 Conclusion: Survival and vulnerability of homes 6. No single risk mitigation can guarantee survival; overall compliance with guidelines is required. 7. Achilles Heel conditions can supersede FireSmart status to almost guarantee home ignition.

45 Conclusion: Vegetation is the major contributor to hazard 8. Untreated vegetation contributed 1/2 to 2/3 of all hazard within 30m of burned homes - Every rule of thumb is being broken - The majority of non-conforming vegetation is planted - Vegetation hazards are within control of property owners

46 Results: Adoption rates* for wildfire risk mitigations VEGETATION IGNITION SITES STRUCTURAL * Fort McMurray, Kelowna, Slave Lake combined

47 Achilles Heel situations Two high-risk situations: o Jackpot junipers (and cedars). o the Eaves of destruction.

48 How do I see ornamental junipers\cedars? Ltd. Institute for Catastrophic Institute for Loss Catastrophic Reduction Loss Reduction

49 Conclusions: Survival and vulnerability of homes 9. FireSmart guidelines seem to be validated, in every study case; address most vulnerabilities well. 10.Many homes were at risk due to hazards on adjacent properties, within their overlapping Priority Zone 1 s and Priority Zones 2 s.

50 Here s the challenge (in my opinion) Preventing future disasters requires shifting primary focus of WUI programs onto attacking the root cause of loss. nnn MOVE AWAY FROM: TOWARD: Fighting fire and fuel around our WUI communities and developments - on public land. Mobilizing residents to take action in their communities to reduce fuel and vulnerability of homes on private land; providing better advantage fire fighters.

51 Adopt 3 strategic objectives Shift emphasis and resources to initiatives that target root causes of the WUI problem: A. Break the WUI disaster sequence, at its weak point B. Reduce the vulnerability of homes to ignition by embers in the Home Ignition Zone C. Facilitate efforts of residents to collectively undertake individual risk mitigation actions at the neighbourhood level

52 How do we achieve those objectives? Accelerate the existing FireSmart Canada Community Recognition Program into full operational mode A major FireSmart Canada initiative Beta version of FCCRP released in 2013 Based on the proven US Firewise program Important progress made; great potential demonstrated Successful pilot programs in Alberta and BC Program in need of expanded logistical and fiscal support

53 What is the FSCCR Program? A citizen led, grassroots program to reduce risk of wildfire losses Operates at the neighbourhood level Empowers WUI residents with understanding, motivates them with a framework to organize risk management actions Residents to develop their own FireSmart plan Overcomes barriers to FireSmart progress Facilitated by trained fire personnel Leads to national recognition

54 How does the FCCRP help? It builds an army! Residents 450+ Homes Highly Effective Cost-efficient Neighbourhoods 9 EMA Personnel 2 Local FireSmart Representatives

55 How can the FS Community Recognition Program be operationalized? Municipal fire departments provide program facilitators FireSmart Coaches Requires 1-2 members in every fire hall to be trained as Local FireSmart Representatives and function part-time as catalysts and facilitators to residents in fire-prone communities. Structural fire fighters have inherent advantages: o Embedded in the community, rapport, 24-7 o Fire expertise, skilled educators, local knowledge o Community trust and credibility o Have skin in the game

56 What would it take to implement a nation-wide FCCR Program? 1. Adaptability: By Fire Departments to continue evolving 2. Commitment By FireSmart Canada and its members 3. 1/50 th of 1% of the $5 billion in losses incurred at Fort McMurray About $1 million in partner start-up funding (national) $250,000 per year to keep it going and growing 56

57 Thank You! Good Reading: Calkin, D.E., J. D. Cohen, M.A. Finney, and M.P Thompson. (2014). How risk management can prevent future wildfire disasters in the wildland-urban interface. Proceedings of the National Academy of Sciences.

58 Discussion and questions.. Alan Westhaver, M.Sc. ForestWise Environmental Consulting Ltd. Fernie, British Columbia (250) (250) Reports available at: Iclr.org\ profiled publications