Given the nature of how wildfires traditionally move through the Bow Valley, the Town of Banff is literally… well, in the line of fire.
In 1842, a massive wall-to-wall fire swept down the Spray Valley, jumped the Bow River west of Tunnel Mountain and moved directly through what is now the heart of the community before it raced off towards Lake Minnewanka.
If Banff had existed in 1842, the flames would have consumed the town.
A Parks Canada map, based on historic fire research done in the 1990s, shows the path that fires in the Banff-Bow Valley region have taken in the past, clearly demonstrating Banff’s precarious position.
The fire map also shows the 1842 fire was not an isolated incident. A fire swept through the Bow Valley from the west in 1850, while in 1885 a fire that edged near the two-year-old village on the south side of the river along Mount Rundle burned a total of 8,400 ha. Between 1880 and 1885 alone, 20,000 ha. (49,420 acres) of forest burned along the Canadian Pacific Railway right-of-way.
And in June 1886, a fire burning near Cascade Mountain covered the village with smoke so dense the Banff Crag and Canyon reported that darkness arrived three hours earlier than usual.
By 1903, the village had been threatened by fire four times in 15 years, according to research done by Cliff White, a conservation biologist with Banff National Park.
In a 1985 paper, Wildland Fires in Banff National Park: 1880 – 1980, White wrote: “All of the 19 historic random ignition fires located in this area would be considered a serious threat to current park facilities and visitors. It takes little imagination to picture the catastrophic results should any of the 1881, 1891, 1905, 1908 or 1923 fires be repeated during a busy summer.”
Ian Pengelly, Banff National Park’s fire and vegetation specialist, says he expects future fires to follow similar patterns to the historic fires.
“Fire traditionally loops around the valley there and into the Spray or vice versa. The prevailing winds take a fire either east down the valley or towards Minnewanka,” he said. In an effort to keep Banff from burning, Parks Canada and the Town of Banff are working together to develop a Tactical Fire Suppression and Evacuation Plan.
Part of this plan includes an ongoing effort to create buffers, or defensible space, around the town this winter by reducing the amount of fuel available to a fire.
“The point is to reduce the intensity of a fire if it comes through the valley bottom.
“We want to prevent a fire in the Spray Valley from crossing the Bow River, but if it did, we want to make sure it doesn’t burn through to the Banff Centre,” Pengelly said of thinning work on Tunnel Mountain.
Using firebreaks to protect the town is not a new idea. Parks began talking about firebreaks as early as 1886, driven by the fear that a fire could come down the valley. At the same time, early park staff were also growing more sensitive of the impression a fire blighted landscape left with early tourists. As a result, Park crews began to build roads and trails to use for firefighting. By 1911, Parks had cut a 100-foot long fireguard along the base of Sulphur Mountain from the Hotsprings Road to Sundance Canyon Road.
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While the ongoing work on the firebreaks are meant to protect people, people have always been the main cause of fires in the Bow Valley, often from campfires and early locomotives.
To start, fire needs a source of ignition and the right weather patterns – conditions are best when ignition overlaps with drought, Pengelly said, adding it is possible to have extensive drought without ignition.
And while the overall level of ignition may be considerably lower now because of fire suppression and education, the fuel load in the forests is increasing, and for Pengelly, the question is: “How long can you put a cork in it?”
The Bow Valley has a large amount of deadfall, caused primarily by wind, rot and insects, and with the dry climate in the valley, wood does not rot quickly.
“The decay doesn’t keep up with the way things grow,” he said.
Thinning is needed to counter those factors. Prior to the fuel reduction project starting last winter, Parks identified a number of areas surrounding the town in three fire risk zones. Current thinning is being done in areas that represent the greatest risk to the town. Work began on these areas in 2004 and will continue through to 2006.
In some areas, Pengelly said environmental sensitivity dictated the priority.
“We have left the areas with the most environmentally sensitive areas for last. We set priorities to achieve the greatest benefit. Areas currently being worked on represent the areas with the most benefit and least sensitivity,” he said.
Crews are currently thinning trees, mostly lodge pole pine, in priority areas south of the Bow River, around Tunnel Mountain and on the west side of the Spray Valley where some areas of the forest have 4,000 to 5,000 trees per ha., not including deadfall.
Where possible, Parks contractors are thinning mechanically, a more efficient method than hand-felling trees. The logging tractor, a six-wheeled machine, uses a clamp-like tool mounted on the end of a boom. It can cut, strip and buck a small tree in about 20 seconds within a 10 to 12 metre radius at a cost of approximately $1 per tree. The machine can also pick up and buck deadfall. The operator then piles the wood in small slash piles.
“We’re cutting and piling small trees. Over the next two years we’ll go in and burn there so people can expect to see these piles on the ground,” Pengelly said, adding the wood will burn with less smoke if it is dry. In the thinning areas, Parks will remove most of the trees under 15 cm in diameter as smaller trees tend to be more of a hazard, a result of the high ratio of tops and branches to the size of the trees. Larger trees tend to “self prune”, shedding dead branches along the trunk, Pengelly said.
In some areas, Parks plans to salvage logs to recover some of its costs.
In an area that offers little fuel for a fire, either standing or on the ground, a fire simply cannot grow larger. Instead, the flames are more likely to stay on the ground, moving along the forest floor as it consumes grass and bushes. Flames do scorch the tree trunks, leaving triangular fire scars that start near the ground and narrow to a point. The scars form on the back of the trees where flames converge from both sides, creating an intense hotspot. The side facing the fire heals and continues to grow. Parks researchers can easily and accurately identify the date of burns by coring the tree at the side of the scar and counting the rings.
All of the cutting in the top priority risk zones should be done by the end of this year, with the slash piles burned by March 2006.
While the slash piles may not look attractive, Pengelly said it is preferable to burn the excess wood in piles as they tend to be easy to access and manage. Crews will remove the remaining debris once the piles have been burned.
The first three-year cycle of this project, scheduled to be complete by 2012, will include approximately 100 ha. of forest at a cost of $750,000.
It’s a small amount given the potential cost a wild fire can have if it moves from the wildland and into an urban area.
“If you have to evacuate the town because you think the fire might burn into town, there’s a huge cost to closing businesses and getting people out of town. Firebreaks also provide a huge social benefit by creating peace of mind and protecting structures. “It’s like having an insurance policy. There’s a huge social benefit to be more comfortable with a fire burning in the Vermillion Valley,” he said.
Views of fire began to change following a big fire season in 1908 that burned towns in the Crowsnest Pass. A fire also burned at the mouth of Vermilion Pass that season. Pengelly said the 1908 fires gave rise to greater education of fire management in 1909. “It became less acceptable… to have fires smoldering around, so there was a huge emphasis on protection and suppression,” he said.
The warden service in Banff began experimenting with early firefighting techniques and equipment, pumps and trucks, in the early 1900s. In fact, White stated that the risk of forest fires forced Rocky Mountain Park to create the Warden Service.
Following the Second World War, fire management programs saw an influx of equipment and military-trained men that led to a better equipped paramilitary fire fighting service capable of suppressing fires. White’s paper shows the number and size of fires has dropped since the early-1880s, largely a result of fire prevention programs.
The summer of 1940 marked the last big fire season in the Bow Valley region, except for the 1968 500 ha. Vermilion Pass fire. However, the writer of an article published in the Crag in 1911 and later used in White’s paper would be pleased to see the current spate of thinning work.
“The scare last summer (1910) from fire on Sulphur showed that we cannot have too many guards and we hope to see the good work continued.”