Copyright © 2022 Albuquerque Journal
Prescribed fires, or controlled burns, are an important tool for restoring ecosystems and preventing catastrophic wildfires.
But prescribed fires that get out of control can devastate communities and landscapes.
To help land managers better predict burn behavior and assess risk, New Mexico scientists are creating tools that can be used in the field to study and plan fires.
Still, the state’s top forester now says agencies will most likely hold off on any more prescribed burns in spring as the devastating Hermits Peak/Calf Canyon wildfire continues to blaze through northern New Mexico.
The Hermits Peak Fire, 12 miles northwest of Las Vegas, is the most recent wildfire in New Mexico that started as a prescribed burn.
Santa Fe National Forest officials started the fire on April 6.
Steve Romero, the Pecos/Las Vegas District Ranger, said the agency typically burns in “small bites,” up to about 1,000 acres.
“Everything was going well, and the forecast told us we had favorable conditions,” Romero said of the burn.
But erratic afternoon winds created multiple “spot fires” that spread outside the project boundary.
At 4:30 p.m. that day, the agencies declared the incident a wildfire and started a full suppression strategy.
“They did the right thing … based on the values at risk and the fire behavior that was taking place,” Romero said.
The Forest Service had originally postponed the burn, scheduled for early March, because of “snow on the ground and forecasted weather.”
The burn was part of a Gallinas watershed protection project.
But now the wildfire has burned enough of the watershed that rains this summer could send ash into the Las Vegas water supply.
Meanwhile, the Calf Canyon/Hermits Peak Fire is now one of the largest wildfires in the country.
On the morning of Friday, April 22, operations sections chief Ralph Lucas said the Hermits Peak Fire was “holding within its containment lines.”
Crews estimated that Hermits Peak was 91% contained.
The team didn’t expect “further movement of the fire.”
But chaotic winds later that day fueled massive fire growth.
The next morning, officials reported that Hermits Peak had merged with the Calf Canyon fire to the west to form one large blaze.
The complex fire has now burned more than 97,000 acres, destroyed hundreds of structures and homes and forced widespread evacuations across San Miguel and Mora counties.
State Forester Laura McCarthy said in an April 23 briefing that “there probably won’t be any more prescribed burning in the spring.”
The state’s top forest official said that fall may prove a safer time to burn.
“(In fall) the days are getting shorter, not longer, the temperatures are getting cooler, not warmer,” McCarthy said. “And so, depending on the kind of monsoon rains that we have, we may have a burn window right after the monsoons and then again in October, November.”
New Mexico Gov. Michelle Lujan Grisham also emphasized the importance of prescribed burns as a land management tool, but said federal agencies like the Forest Service should do more to mitigate risks.
“I’m barking at the feds about this – please don’t do prescribed burns during windy season,” Lujan Grisham said. “I hope … that they’re going to have to maybe relook at – because the conditions are so much more extreme, maybe they have to narrow the window about when we do prescribed burning and in what areas.”
Rod Linn, leader of Los Alamos National Laboratory’s atmospheric modeling and weapons phenomenology team, studies how fire interacts with the atmosphere.
“The buoyancy that comes from the heating of the fire feeds back on the wind field around the fire, and redirects it and changes the way it then heats the unburned fuel and spreads,” Linn said.
LANL worked with the Forest Service to develop the FIRETEC tool, which models the shape and growth of wildland fires and prescribed burns.
FIRETEC runs on supercomputers and is primarily used for researching past fire behavior.
A newer LANL modeling tool, QUIC-Fire, can run on a laptop and is more accessible for crews planning fires or predicting wildfire growth.
The tool helps agencies design ignition patterns and predict where smoke will flow.
The lab was not involved in helping plan the prescribed burn that turned into the Hermits Peak Fire.
Vegetation is a major factor in modeling fire behavior.
“In an open grass prairie you might get a really fast-moving fire, whereas if you take that same ground fuel and move it under a canopy, you might get substantially slower fire spread because the trees actually slow the wind down,” Linn said.
Both models can help determine how different vegetation influences a fire.
Other prescribed burns turned wild
The Cerro Grande Fire in May 2000 also began as a prescribed burn.
By the time crews extinguished the blaze a month later, Cerro Grande had burned about 43,000 acres in and around Los Alamos, destroyed 235 homes and caused $1 billion in damage.
The destruction included 7,500 acres of LANL property and $331 million in damage to the lab.
Earlier this month near Roswell, a prescribed burn conducted by the U.S. Bureau of Land Management turned into the Overflow Fire.
An “unexpected fire whirl” carried fire across the control lines. A fire whirl is a heat-fueled vortex that can include flame, debris and ash.
The Overflow burned 1,900 acres and damaged power lines.
Agencies need to do “a lot of homework” when planning burns, Linn said.
Fuels have to be dry enough to catch fire, but not so dry that a fire could spread out of control.
Winds must be at certain speeds and directions for the fire to stay inside project boundaries.
Topography influences how a fire moves – and how quickly.
Smoke is a big factor in planning and managing burns.
Fire smoke can impact air quality and form ozone and smog.
“If you’re burning anywhere near a community or critical infrastructure, we really need to understand the smoke,” Linn said.
All those ingredients form a very specific window of time for crews to safely set prescribed burns.
New Mexico House Republican Floor Leader Jim Townsend has called for the Forest Service to “be held accountable” for the fire.
He said the decision to proceed with the prescribed burn was “negligence.”
“It has become increasingly clear that the federal government has been operating in an unsafe manner when it comes to forest management,” the Artesia Republican said in a statement. “New Mexicans need to be able to trust that the federal government has their safety in mind and that the reckless actions taken by USFS do not go unanswered in this latest incident.”
He also criticized the governor for not being even more critical of the federal agency for starting the Hermits Peak fire.
Even with the risk, prescribed burns are key for proactive land management in a changing climate.
Forest management for much of the last century excluded any type of fire from the landscape.
Those practices created overgrown forests and swaths of dead trees ripe for burning.
A more arid New Mexico climate is also helping to fuel a recipe for catastrophic, unnaturally large wildfires.
Prescribed burns help agencies put “good fire” back on the landscape.
“Science and our own experience with many prescribed burning projects and thinnings that we have conducted within the Gallinas Canyon confirms that treatments like thinning and prescribed burnings are our best chance for healthier forests,” Romero said.
Linn said he sees his team’s tools as important for helping agencies restore natural burn cycles while weighing risks of prescribed burns.
“It’s about getting fire behavior in the right regime that helps the ecosystem,” he said.
Theresa Davis is a Report for America corps member covering water and the environment for the Albuquerque Journal.