14LA-Lagoon FireMay 21, 2014Case Study:How fuel treatment areas affect wildland urban interface �res

saskatchewan.ca/fire

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Acknowledgements

This case study was compiled of information and data collected by Camille Harris, Wildfire

Prevention and Mitigation Specialist, Wildfire Management Branch, Saskatchewan Ministry of

Environment. Thank you to all of those who contributed including:

Larry Fremont, Education and Prevention Coordinator, Wildfire Management Branch,

Prince Albert, Saskatchewan.

Owen Price, Wildfire Prevention and Mitigation Specialist, Wildfire Management Branch,

Prince Albert, Saskatchewan.

Wes Boehr, Forest Protection Officer, La Ronge Fire Base.

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Contents Acknowledgements ........................................................................................................................................ i

List of Figures ................................................................................................................................................ ii

List of Tables ................................................................................................................................................. ii

Introduction .................................................................................................................................................. 1

Fire History .................................................................................................................................................... 3

Weather Observations .................................................................................................................................. 5

Fuel Treatment Background ......................................................................................................................... 5

Wildfire Behaviour Analysis .......................................................................................................................... 6

Conclusion ................................................................................................................................................... 11

List of Figures FIGURE 1 - MAP OF 14LA-LAGOON FIRE NEAR THE COMMUNITY OF STANLEY MISSION ................................................ 1

FIGURE 2 - CL215T DROPPING FOAM ALONG ROAD NEAR THE GAS STATION. .............................................................. 2

FIGURE 3 - HELICOPTER BUCKETING ON HOTSPOTS. ................................................................................................. 2

FIGURE 4 - FIRE ORIGIN ALONG TRAIL. ................................................................................................................... 3

FIGURE 5 – AIR TANKER ARRIVAL AND DEPARTURE PHOTOS. ..................................................................................... 4

FIGURE 6 - AERIAL PHOTO OF BURNT AREA AND INITIAL ATTACK CREW MEMBER WALKING WITHIN TREATED AREA. ............ 4

FIGURE 7 - THINNED AREA OF FUEL TREATMENT PROJECT ........................................................................................ 5

FIGURE 8 - MAP SHOWING LOCATION OF SPOT FIRES ............................................................................................... 6

FIGURE 9 - LAGOON FIRE NEARS THE COMMUNITY .................................................................................................. 7

FIGURE 10 - PEGASUS FIRE GROWTH PROJECTION 6 HOURS. .................................................................................... 7

FIGURE 11- SPOT FIRES UP TO 85.3 METRES IN FRONT OF FIRE. ................................................................................. 8

FIGURE 12 - SCORCH HEIGHTS WITHIN THE SOUTHERN PORTION OF THE TREATED AREA ................................................. 8

FIGURE 13 – BURNT AREA WITHIN FUEL BREAK. ..................................................................................................... 9

FIGURE 14 - SAMPLE PLOTS TREATED VS UNTREATED ............................................................................................ 10

FIGURE 15 - AERIAL VIEW OF THE LAGOON AND STANLEY FIRES. ............................................................................. 10

FIGURE 16 - LAGOON AND STANLEY FIRE MAP ..................................................................................................... 11

FIGURE 17 - BURNT PILES THAT WERE LEFT WITHIN THE THINNING PROJECT. ............................................................. 12

FIGURE 18 - LAGOON FIRE, UNDER CONTROL. ...................................................................................................... 13

List of Tables TABLE 1 - OBSERVED WEATHER THE AFTERNOON OF MAY 21ST 2014. ...................................................................... 5

TABLE 2 - UNTREATED PLOT INFORMATION ........................................................................................................... 9

TABLE 3 - TREATED PLOT INFORMATION ............................................................................................................. 10

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Introduction The Lagoon Fire (14LA-Lagoon) was reported

May 21, 2014 at 14:31 hours and was within 1

kilometer of the First Nation community of

Stanley Mission. The fire originated southwest

of the community, ran approximately 700

metres towards the community and grew to

21.4 hectares. This fire was within the Full

Response Community Zone and burnt on Crown

land. It started in continuous C2 Boreal spruce

fuels and ran into an area that had previously

been thinned as a fuels management project.

FIGURE 1 - MAP OF 14LA-LAGOON FIRE NEAR THE COMMUNITY OF STANLEY MISSION

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FIGURE 2 - CL215T DROPPING FOAM ALONG ROAD NEAR THE GAS STATION.

FIGURE 3 - HELICOPTER BUCKETING ON HOTSPOTS.

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Fire History

The Lagoon Fire was

discovered at 14:31

hours by Forest

Protection Officer

Wes Boehr while en

route to the nearby

Stanley Fire, which

also started on May

21, 2014. The

Stanley Fire was just

across the bay to the

west of the Lagoon

Fire. Due to the

Lagoon Fire’s close

proximity to the

community, air

tankers were

diverted from

another fire to

action the Lagoon Fire. Within 16 minutes of

discovering the wildfire at a Rank 1 surface fire,

it quickly escalated to a Rank 5 crown fire

before suppression began. By 14:45 hours, the

Stanley Mission type 2 fire crew was at the fire

and began pump and hose line setup from the

lake north of the fire. Helicopter 31, a Bell 204B,

was returning to La Ronge from Southend and

landed at the Stanley Mission schoolyard to

attach a bucket to help support the fire crews.

At 14:47 hours, Bird Dog 167 with CL215T’s

#217, #218 and #219, along with CV 580’s #471

and #473, were over the fire and began air

support. An initial attack crew from La Ronge

was also dispatched during this time to support

the local type 2 crew already working the fire.

FIGURE 4 - FIRE ORIGIN ALONG TRAIL.

Bird Dog 167 was released from the fire for

refueling and was replaced by Bird Dog 161.

Another CL215 was requested to support the

fire. The CV580’s laid retardant lines along an

existing fireguard, from the road to the lake,

approximately 85 metres west of the local gas

station. Another retardant line was placed to

the west of the point of origin to prevent the

fire from spreading in that direction. Three

CL215T aircraft dropped water and foam

directly on the main fire while Helicopter 31

focused on bucketing on four small spot fires

that had jumped the existing fire guard. At

17:11 hours the fire was being held and 20

minutes later, the fire was reported at an

intensity of level 1, with airtankers working the

hotspots and ground crews working the head of

the fire with a hose line.

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In total, the CL215T’s dropped 61 loads of water

(73,200 gallons) and 28 loads of foam (33,600

gallons), along with the CV580’s delivering four

loads (6,560 gallons) of retardant to the fire. All

air support was off the fire by 18:50 hours that

day.

Ground crews continued to action the fire until

midnight and were back at the fire by 09:20

hours the next day. For the next four days,

crews continued patrolling the fire and mopping

up hotspots. On May 26, the fire was scanned

and no hot spots were found. The fire was

declared out on May 27, 2014.

A conservation officer from the Ministry of

Environment’s Compliance and Field Services

office conducted an investigation into the cause

of the fire. The conservation officer determined

that the fire was intentionally set by individuals

under the age of 12.

FIGURE 5 – AIR TANKER ARRIVAL AND DEPARTURE PHOTOS.

FIGURE 6 - AERIAL PHOTO OF BURNT AREA AND INITIAL ATTACK CREW MEMBER WALKING WITHIN TREATED AREA.

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Weather Observations

TABLE 1 - OBSERVED WEATHER THE AFTERNOON OF MAY 21ST 2014.

Fuel Treatment Background

FIGURE 7 - THINNED AREA OF FUEL TREATMENT PROJECT

The community of Stanley Mission has had

ongoing fuel management work completed

within and around the community since 2007.

The thinned area that the Lagoon Fire burnt up

to was completed in the winter of 2008/2009.

This fuel management project was funded by

Western Economic Diversification Canada as

part of their economic stimulus initiative and

was completed jointly by Saskatchewan’s

Ministry of Environment Wildfire Management

Branch and the Lac La Ronge Indian Band. The

Prince Albert Grand Council worked directly

with Western Economic Diversification Branch

to receive the funding for the project and was

responsible for the administration of the

project.

The project area was 4.45 hectares in size and

the prescription was to thin the softwood

(coniferous) stands by hand to a minimum

crown spacing of two to three metres with a

desired outcome of six stems per 100 square

metres. Ladder fuels were removed and the

remaining trees were pruned to a height of two

metres. All branches and dead and down fuels

were piled and burnt within the project area.

All salvageable wood was piled and left for

firewood to be used by local community

members.

Station Temp RH Wind Direction Wind Speed Distance from Fire

La Ronge 19 26 190 22 52.3 km 226°MN

Otter 20 25 178 19 23.1 km 316°MN

Station FFMC DMC DC ISI BUI FWI

La Ronge 92 31 80 17 32 26

Otter 93 37 69 16 36 27

Station ROS C2 m/min Head Fire Intensity C2 (HFI) kW/m Crown Fraction Burn C2 (CFB)%

La Ronge 19.1 13200 98

Otter 19.6 14700 98

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Wildfire Behaviour Analysis The daily fire report comments for the Lagoon

Fire started on May 21, just one hour and 32

minutes after the fire started: “The fire hit the

thinning project and this project knocked the

fire to the ground.”

On May 22, Wildfire Prevention staff arrived on

site to collect information regarding the

effectiveness of the fuel management site.

While at the location of the fire, assessment

staff spoke with the local crew leader, who was

one of the first people to respond. When

questioned about the fire behaviour, he

specified

that his crew was able to safely run a hose line

up to the head of the fire, within the fuel break,

because the intensity of the fire had dropped as

it came into the treated area.

The total area burnt within the fuel treatment

area was 2.01 hectares. The fire burnt through

the fuel break on the northern portion where it

was only 50-60 metres wide. In this narrow

portion of the fuel treatment area the main fire

was stopped at the fire guard but embers

spotted over the fireguard in four locations, the

furthest distance being 85.3 metres from the

fire line. The fire did not burn through or spot

over the southern half of the break which was

200 metres wide.

FIGURE 8 - MAP SHOWING LOCATION OF SPOT FIRES

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FIGURE 9 - LAGOON FIRE NEARS THE COMMUNITY

FIGURE 10 - PEGASUS FIRE GROWTH PROJECTION 6 HOURS.

A Pegasus1 Wildfire Projection was completed for the Lagoon Fire. The six-hour projection shows an area

burnt of 91.9 hectares which includes the northwest corner of the community.

1 Pegasus is an online version of Prometheus that was developed by the Canadian Forest Service in collaboration

with Saskatchewan’s Ministry of Environment Wildfire Management Branch.

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FIGURE 11- SPOT FIRES UP TO 85.3 METRES IN FRONT OF FIRE.

FIGURE 12 - SCORCH HEIGHTS WITHIN THE SOUTHERN PORTION OF THE

TREATED AREA

Scorch heights within the thinned area were

recorded to be a maximum of 1.25 metres high.

Spot fires were observed up to 85.3 meters in

front of where the fire line was held. These spot

fires were in C2 fuels that had not been

included in the fuel treatment area.

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FIGURE 13 – BURNT AREA WITHIN FUEL BREAK.

Data was collected from two 100 square metre sample plots, one in the treated and one in the

untreated area within the vicinity of the Lagoon Fire.

Untreated area

Untreated Plot

Black Spruce

8100 stems/m

Birch 400

stems/ha

Alder 100

stems/ha

Labrador Tea 20%

Feather Moss 80%

Height Class 15m

Crown Separation 0-0.5m

Crown Closure 90%

Crown Base Height 2m

TABLE 2 - UNTREATED PLOT INFORMATION

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Treated Area

The 14LA-Stanley Fire, pictured in the

background of Figure 15, was reported on May

21 at 13:54 hours, just half an hour before the

Lagoon Fire. Both of these fires were human-

caused. The Stanley Fire consumed 9,889

hectares of the boreal forest before being called

out on June 19, 2014. This fire may have

influenced the direction and intensity of the

Lagoon Fire due to its close proximity.

Treated Plot

Black Spruce 1000

stems/ha

Birch 100

stems/ha

Feather Moss 25%

Labrador Tea 25%

Blue Berry 10%

Height Class 15m

Crown Separation 2-3 m

Crown Closure 25%

Crown Base Height 2m

TABLE 3 - TREATED PLOT INFORMATION

FIGURE 14 - SAMPLE PLOTS TREATED VS UNTREATED

FIGURE 15 - AERIAL VIEW OF THE LAGOON AND STANLEY FIRES.

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FIGURE 16 - LAGOON AND STANLEY FIRE MAP

Conclusion

Good burning conditions combined with highly

flammable fuel types resulted in the Lagoon Fire

quickly becoming a full crown fire that was

heading directly toward the community of

Stanley Mission. Tankers initially actioned the

fire with limited success but once the fire

reached the treated area the intensity dropped

and the tankers were able to successfully action

the fire. Bird Dog and air tanker pilots

commented that their drops were very effective

within the treated area, given the combination

of the decrease in fire intensity, the ability to

see the fire line, and the openness of the stand.

Interviews with ground crews who were tasked

with suppressing the fire revealed that they

were able to safely access the head of the fire

as soon as it hit the treated area because of the

reduction in intensity and rate of spread. The

reduction of the amount of available fuel,

combined with the effectiveness of air tanker

drops within the thinned area, both contributed

to result in a reduction of fire behaviour.

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When Education and Prevention staff mapped

the boundary of the fire they documented that

the fire burned into the fuel break a maximum

distance of 120 metres. It was noted that the

firewood piles that were left from the original

thinning project were the one significant fuel

source that sustained the fire when it burnt

through the wider portion of the thinned area

as a surface fire. These piles were

approximately two to three feet high and four

feet long and were piled in the thinned area

with full sun exposure. It was not evident that

the piles produced embers to advance the fire

but they appeared to have sustained the

surface fire spread further into the thinned

area.

Where the treatment area was less than 50

metres wide an intermittent crown fire

progressed through the treated area up to the

fireguard and the higher intensity resulted in

spot fires across the existing fireguard that the

treated area was tied into. It was noted that

the treatment completed in this area did not

meet the desired prescription of the project,

leaving enough fuel for the fire to sustain high

intensity. For this fuel type the thinned area

should be a minimum of 100 metres wide and

be thinned to the stated prescription to be

effective during high hazard conditions. It is

important to note that fuel treatment areas rely

on suppression support to be effective in this

type of fuel.

Based on documented fire behaviour and

suppression effectiveness, it can be confidently

determined that the fuel break played a

significant role in the control of the Lagoon Fire

and likely prevented the loss of structures

within the community.

FIGURE 17 - BURNT PILES THAT WERE LEFT WITHIN THE THINNING PROJECT.

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FIGURE 18 - LAGOON FIRE, UNDER CONTROL.