An 80-page report (4.7Mb) released by the U.S. Forest Service concluded that the management of the prescribed fire that escaped and merged with another escaped prescribed fire to become the largest wildfire in the recorded history of New Mexico, generally followed the approved prescribed fire plan for most but not all of the parameters. The people on the ground felt they were close to or within the prescription limits but fuel moistures were lower than realized and increased heavy fuel loading after fireline preparation contributed to increasing the risk of fire escape.
The prescribed fire on the Santa Fe National Forest in northern New Mexico east of the city of Santa Fe was one of the units within the Gallinas Prescribed Fire Project Area. The first burning activity in early October of 2017, was the ignition of piles of debris left after forest thinning projects. Less than expected snow allowed the fire to spread away from the piles over the next three months. In late December they began to suppress the fire, and on January 18, 2018 it was converted to a wildfire. A Facilitated Learning Analysis found that“communication” and “prescribed fire preparation and risk” were two common themes.
In a continuation of that large multi-unit project, on April 6, 2021 at 11:34 a.m. firefighters ignited the test fire on the Las Dispensas prescribed fire, expected to be 150 acres. At 12:34 p.m. the test was considered successful and the project commenced.
The first small spot fire occurred at 1:35, which was controlled. At 2:26 a quarter-acre spot fire was caught.
Radio communication with some of the personnel was discovered to be a problem. It was later found that Bravo Holding was using a separate “crew net” and were not monitoring the planned frequency.
Ignition stopped a couple of times as spot fires were suppressed, but by about 4 p.m. when the relative humidity dropped to 10 percent there were at least a dozen spots. At 4:06 the Burn boss requested contingency resources and at 4:15 as groups of trees began torching all resources were pulled off the fire due to the increasing fire intensity. At 4:25 Dispatch reported that the contingency resources were physically located in Taos, New Mexico at the Fire Summit (an annual training exercise). Taos is approximately 70 miles from the prescribed fire.
At 4:38 Dispatch advised the Agency Administrator that the Burn Boss and the Fire Management Officer recommend it be declared a wildfire — about four hours after the primary ignition began. The Agency Administrator made the wildfire declaration and at 4:50 the incident was named the Hermits Peak wildfire.
On April 22 the Hermits Peak Fire merged with the Calf Canyon Fire, another escaped prescribed fire on the Santa Fe National Forest. As of June 22 the blaze has burned more than 341,000 acres.
Weather
The prescription for broadcast burning required that the relative humidity be between 12 and 60 percent. The spot weather forecast issued by the National Weather Service at 8:53 a.m. on April 6 predicted the minimum RH would be between 9 and 13 percent, west winds 10 to 15 mph gusting to 25, and 54 to 58 degrees.
During the project on April 6 weather conditions were measured by a lookout once an hour using a hand-held Kestrel instrument. With that device the readings appeared to be within the prescription parameters except for the observations at 4 p.m. when it showed the RH had dropped to 10 percent.
From the report:
“Regarding temperature (dry bulb and wet bulb) and relative humidity, the observations recorded by the lookout showed a cooler and more moist bias when compared with other observations of weather and fire behavior on the site. Specifically, relative humidity readings taken from the Kestrel differed from what the relative humidity values should have been if calculated using the National Wildfire Coordinating Group standard tables for that elevation and the dry bulb and wet bulb observations. The relative humidity values recorded from the Kestrel provided values that are nearly 10 percent higher than those calculated.”
The recalculated RH at 4 p.m. was actually 6 percent, not 10 as shown on the Kestrel. One of the Firing Bosses also took readings and used the NWCG standard tables, which were similar to the recalculated values from the lookout’s Kestrel.
To summarize the weather, the forecast predicted the RH to be 9 to 13 percent, possibly below the prescribed 12 percent minimum, but it actually dropped as low as 6 percent, well below the prescription.
Fuels
Fine and heavy fuel loading increased in the years after the prescribed fire plan was developed, resulting from a combination of canopy opening from thinning (fine fuels) and fireline preparation (heavy fuels). This contributed to high fire intensity, torching, prolific spotting, and resistance to control.
The foliar fuel moistures were low and contributed to the transition from surface to crown fire. Fuel moisture samples taken from March 16 to April 3 showed a significant downward trend that contributed to the transition from surface to crown fire and increased spotting potential. Foliar moistures were listed to be sampled in the prescribed fire plan but were not part of the prescription.
The report’s conclusions, findings, and lessons learned
- There was no nearby Remote Automated Weather Station (RAWS) in working order representative of conditions at the burn site. If available, the data could have improved situational awareness.
- A thinning project in the burn area opened the canopy in some areas, allowing more sunlight which led to lower fuel moistures. Heavy ground fuels resulting from the construction of fireline for the burn project added to the fuel loading. This contributed to higher fire intensities, torching, spotting, and higher resistance-to-control.
- Low live fuel moistures facilitated the transition from surface fire to torching and spotting outside the unit boundaries.
- The prescribed fire plan mentioned that the Energy Release Component (ERC) which is an indication of the potential intensity of a fire, was to be monitored, but did not specify how the element would be used. On the date of the prescribed fire it was 37, far above average for the date which was 23. The highest ever recorded on that date was 41. Higher numbers indicate greater fire intensity.
- There was an underestimation of the minimum holding and contingency resources needed. After numerous spot fires occurred, the Burn Boss requested the contingency resources, but they were 70 miles away.
- A clear recognition and acknowledgment of long-term drought and climate factors versus short-term weather events would have led toward better situational awareness of the fire environment and could have resulted in more favorable outcomes.
- The test fire was initiated in an area of the unit that was not representative of the rest of the unit. On several occasions, both before the burn was ignited and after the test fire was considered and accepted, some personnel felt that the dry conditions would result in difficult burning conditions and an increase in risk, but they accepted the assignment.
- Consider requiring overhead, such as Firing Boss, Holding Boss and other staffed positions, to document support of the agreement with the Test Fire or the Go/No-Go decision.
- Administrative boundaries limited the selection of potential control lines. The prescribed fire unit designation followed boundary lines from private property and other land designations, such as wilderness, and not necessarily advantageous fuels changes or topography.
- Use the existing authority in the “Wyden Amendment” that allows managers of federal lands to spend funds to conduct treatments on adjacent non-federal lands to improve the viability of, and otherwise benefit, fish, wildlife, and other biotic resources.
- District fire employees perceived pressure to “accomplish the mission,” which may have led to taking greater risk.
- Records show the Prescribed Fire Burn Boss Type 2 (RXB2) performed as a fully qualified RXB2 at least 12 times since 2015.
- Invest in education opportunities for continued learning in science and technology specific to fire behavior and fire environment. Consider workshops tailored for prescribed fire practitioners that address today’s challenges related to environmental and social conditions.
- Prescribed fire programs and projects should invest in staffing, training, planning and other supporting resources commensurate with the priority and complexity of prescribed fire projects.
- Consider Incident Management Teams when implementing complex prescribed fire projects.
- Increase support for existing Burn Bosses by activating Planning Section functions when complexity warrants the additional capacity.
- Establish an interagency training facility, such as the National Interagency Prescribed Fire Training Center, that would be located in the Western U.S. and focus on the additional complexities involved with western fuel treatments.
- Learn from indigenous communities about cultural land management practices.
- Invest in education opportunities for continued learning in science and technology specific to fire behavior and fire environment. Consider workshops tailored for prescribed fire practitioners that address today’s challenges related to environmental and social conditions.
And this from the report
“We ask them to make up ground on long-needed and far-behind proactive restoration work while barely allowing time to recover from a previously taxing wildland fire response and preparing to respond yet again. We ask them to restore fire process to ecosystems that have evolved to burn, but many of which are now primed for extreme fire behavior due to our own decisions to exclude or suppress fire in these areas.
“To accomplish this level and frequency of prescribed fire on the landscape, we must ensure that practitioners have access to the best science, technology and tools, and that they are confident and practiced in their usage. We need an approach to planning and implementing prescribed fire that’s as robust as our Incident Management Teams’ response to wildfire.”
The 10-year plan
The 10-year plan released in January by the Forest Service for prescribed fire and other fuel projects calls for tripling the number of acres treated on National Forest System Lands in the West and other Federal, State, Tribal, and private lands in the West, increasing from about 2.5 million acres a year to 7.5 million.
Our take
The report said, “District fire employees perceived pressure to ‘accomplish the mission,’ which may have led to taking greater risk.”
If they feel pressure now, how will they feel when the number of acres treated needs to increase substantially? Will there be a corresponding escalation in Burn Bosses, Holding Bosses, full time prescribed fire planners, NEPA compliance capacity, crews, and weather windows?
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