The Fort Frances 014 wildfire west of Shebandowan remains out of control at 51,806 hectares, but while cooler, damp weather has slowed its growth in recent days, firefighters say the threat is far from over.
“Leading up to the fire, the ground was very dry,” Shebandowan Fire Chief David Delzotto said. “When the fire happened, it was actually also burning into the ground.”
Delzotto said the dry conditions allowed the wildfire to burn into the organic material beneath the surface, creating smouldering hotspots that can continue burning long after visible flames have disappeared.
“They’re finding fire up to 30 centimetres below ground,” he said, referencing information from an MNR report. “You could have a smouldering fire a foot below the ground.”
The Ministry of Natural Resources said rainfall over the past six days has reduced fire behaviour on Fort Frances fires 14, 15 and 38, limiting growth and improving air quality. However, field reports indicate the fires continue to burn up to 30 centimetres into the organic, or duff, layers of soil, where dry conditions persist.
In a Thursday Facebook update, the Shebandowan Fire Department warned that “the fire burned so deep that there are muskeg fires that could burn for months,” adding that while there is no major fire front moving toward the community, hotspots remain throughout the fire area.
Delzotto said those hotspots can remain hidden beneath charred ground and become active again if hot, dry and windy weather returns.
“All your fuel above the ground might be charred and burnt," he said. "But behind the original fire you could have hot spots under the ground that are just sitting there smouldering."
The MNR said deep-burning hotspots are a common feature of wildland fires and can re-emerge as surface fires if conditions dry.
They are located using infrared scanners mounted on helicopters, fixed-wing aircraft and satellites before firefighters extinguish them using hand tools, pumps, hoses and water-bucketing helicopters.
“In some spots you have to almost physically dig down and apply water to get those spots out,” Delzotto said. “And it could take a month or two.”
The ministry said more rainfall and continued suppression efforts will be needed, noting that fires burning into organic soil layers typically require more time and effort to extinguish.
Delzotto said the biggest concern now is complacency.
“The smoke has gone away, we’ve had some rain, and a lot of people think, okay, everything’s sort of back to normal,” he said. “But we’re still not quite out of the woods.”
He warned that several days of hot, dry weather could quickly increase fire activity.
“It’s not like the ground has been totally saturated and there’s no chance of a fire again,” Delzotto said. “If we have three or four really warm days, the situation could change again quite quickly.”