Hermit's Peak/Calf Canyon Fire 2022

There are close to 700 functioning acequias in New Mexico, according to the state’s Acequia Commission, and a score more in Colorado. Many of these gravity-fed ditches that bring runoff from the mountains to the fields have been operating for three centuries, and some were likely dug long before that.

Most acequias are open channels and many farmers irrigate by flooding their fields, which means that lots of water leaches away or evaporates. Yet studies show that the dirt waterways provide more robust environmental benefits than concrete culverts and metal pipes, says Sam Fernald, professor of watershed management at New Mexico State University in Las Cruces and the head of the school’s Water Resources Research Institute.

Seepage—which can range between one-third and one-half of the flow—replenishes groundwater while also fostering a rich wetlands around each ditch, Fernald says. A number of other studies suggest that irrigating with acequias extends the hay-growing season and so boosts the number of cattle that can be grazed. And the largest benefit, though much harder to quantify, is that the acequias create communities that serve as stewards of the environment.

All quotes above excerpted from Robert Neuwirth's May 17, 2019 National Geographic article, "Centuries-old irrigation system shows how to manage scarce water".

A series of wildfires began in New Mexico's Sangre de Cristo Mountains in April 2022. Two of those fires, Hermits Peak (April 6) and Calf Canyon (April 19), merged on April 22, and are now known as the Hermits Peak fire.

Over 341,735 acres of pine, fir, pinyon, scrub brush, grasses, and forbs along the Southern Rocky Mountains and Southern Rocky Mountain Foothills fueled the fire, pushed along by extreme, high velocity winds that are very uncommon to the area. More than 60% of the acres affected are privately-owned ranchlands.

By July 9, 2022, the Hermits Peak fire was 93% contained and was the second largest wildfire in the United States for this 2022 fire season, and the largest ever experienced in New Mexico.

By current, July 9, 2022, accounts, the Hermits Peak fire has yielded the following impacts:

• 903 structures lost, including over 340 homes
• $270 million cost-to-date for fire suppression actions
• 534 square miles burned, roughly 1/3 the size of Rhode Island
• 186 miles of acequias and multiple connected waterbodies potentially at risk
• 1,000’s of people evacuated and 100’s indefinitely or permanently displaced
• millions of dollars in recovery, disaster prevention, reclamation and future restoration costs
• 1000’s of insurance claims due to losses
• 100’s of NRCS employees deployed from multiple states and within NM for EWP response
• Thankfully, the most important number: 0 human lives lost

This shows the 186-mile acequia network within the Hermits Peak burned area, including a 2-mile buffer around the burn. The bright blue lines are the acequias inside the buffer; the pale blue lines are the acequias outside the buffer.

Water is the lifeblood of the West. One of the recovery efforts led by NRCS is to protect as many acequias and waterbodies, pastures, or livestock tanks they bring water to. If the acequias are not protected, water won't reach the areas where it is most needed.

This area of New Mexico, like much of the West, is an area rich in culture that dates back many centuries. Communities in the path of the fire will rebuild, because it's in their nature to do so. But where do they start? How do you triage over 341,700 acres and the unique natural resources and heritage, to determine areas of greatest need?

Technology fuels recovery. That's where the NRCS Conservation Effects Assessment Project on Grazing Lands (CEAP-Grazing Lands) is working with the New Mexico NRCS field offices and Emergency Watershed Protection Project response teams.

We've teamed up with a private technology firm, Teren Inc., to deliver the latest in spatial analysis tools, hazard prediction and detection, and game-changing data layers that will help us rebuild communities, infrastructure and culture. So in a sense, we are using the future to protect the past.

New computer and imagery technologies can now be used to aid recovery efforts. In the not-too-distant past, these tools did not exist. Triage and recovery efforts were done manually, with topographic maps, field surveys, and laborious damage estimate modeling. Fast-forward to today, and we can do in minutes and hours, what used to take days and weeks.

The following maps show the change in conditions as the Hermits Peak burn area is analyzed for risks and hazard levels. Each map sequence is captioned, to help convey what is being shown. The maps provide guidance to NRCS and landowners, to effectively determine locations and kinds of stabilization and conservation measures needed.

The first phase of this emergency response was to provide maps and associated spatial data to the NRCS teams on the ground, within 7 days, to help them triage potential hazards and degrees of risk. All of the maps below were produced using publicly-available data.

Map Sequence 1, below. The left pane shows the Hermits Peak burn area, with U.S. Forest Service (USFS) indicated in the cross-hatched areas. The right pane shows the Soil Burn Severity zones, as determined by the USFS and NRCS.

Map Sequence 2, below. The outlined area in both images is the Hermits Peak Fire footprint. The left pane shows the hillshade image using the 10-meter Digital Elevation Model (DEM). The right pane classifies the area into different percent-slope classes (right).

Knowing where the slopes are steep can often indicate where potential hazards are greater. For example, when it rains, soils on steeper slopes will be carried away with the water moreso than soils on flatter slopes. Understanding the slope is one of the first stages of determining where potential hazards may be great, so the need to treat or protect the hillslopes and creeks is often high.

The slope values most crucial to stabilization efforts are typically between 20% and 55%. Slopes less than 20% are less susceptible to high erosion amounts, while slopes in this area over 55% are either inaccessible, are dominated by rock outcrops (little to no soil), or are generally difficult to stabilize.

So the sweet spot for stabilization and rehabilitation, at this stage of the initial analysis, are areas where the Soil Burn Severity is High or Moderate, and the Slopes are between 20-55%.

Map Sequence 3, below. Here, the left map combines the High and Moderate Soil Burn Severity areas with the different Percent Slope classes. The right map represents the areas in greatest need of stabilization and reclamation, weighted by percent of the micro-watershed that they comprise. Note that the final maps provided to NRCS removed areas such as rock outcrops that don't contribute to soil loss.

So the "impact" (Low to High) is the amount of influence that the area has on the micro-watershed, in terms of potentially hazardous events such as the amount of soil erosion. Note that this analysis also uses Topographic Position Index to find slopes less than 20 percent that burned, will likely contribute flow to the lower area, and should be stabilized, even though they are not in the stabilization sweet spot.

Map Sequence 4, below. In the above map sequence, the term "micro-watershed" was used. Here, the upper left map delineates each micro-watershed in the burn area. They were derived from the USGS National Elevation Dataset (NED) 10-meter elevation model, and are about 250 acres in size. The color of each micro-watershed shows the summarized percent-area within each that the top burn stabilization zones comprise. The upper right map simply overlays the physical structures in the area, as indicated by the pink "dots".

The lower left map is the same as the upper right, but it contains an area of interest within the blue box. That area of interest is shown in the lower right map, where we've zoomed-in to show the soil burn severity and structure locations within the smaller area. This type of detail is essential in understanding and mitigating any risks. All of the mapping products are scalable from roughly 1-meter (field) to several kilometers (regional). Again, please note that the final mapping products passed to NRCS considered rock outcrops and other non-soil areas in the hazard determinations.

In this analysis, a micro-watershed is approximately 250 acres in size, and would essentially "nest" into the USGS Watershed Boundary Dataset (Hydrologic Unit Code) at the 14-digit scale. Assessing the need for treatment is best performed within a watershed context, rather than as clusters of pixels on a map, to illustrate the connectivity of resource concerns and ensure proper scale and design of conservation measures.

The addition of micro-watersheds and structures introduces the complexity of the emergency response effort to stabilize natural resources and reduce hazard risks. It's evident that some of the "top stabilization zones", shown as red-colored micro-watersheds, are important to stabilize and treat.

The EWP Program allows communities to quickly protect infrastructure and land from additional flooding and soil erosion. Referring back to Map Sequence 4, some of the "high impact" micro-watersheds are not connected to life or property, based on where structures are located. In this case, the NRCS emergency response team may decide to treat micro-watersheds with a lower reclamation rating (orange- or green-colored) and higher concentration of structures, in order to protect life and property.

Values At Risk

Physical structures -- homes, outbuildings, hospitals, schools, cellular towers, etc. -- are not the only values-at-risk that NRCS assesses during an emergency response. Resources such as the acequias, livestock ponds, lakes, reservoirs, pasture and forage resources for livestock production, wildlife habitat requirements, and so on, are also catalogued and assessed. If any are found to be at potentially high risk to future hazards, such as flood, sedimentation, or woody debris flows, NRCS will take appropriate measures to stabilize those values as well.

Mapping Sequence 5, below. Adding acequias, one of the many values at risk, to the analysis reveals the potential impact to those cultural waterways. The first map (left) categorizes different reaches of each acequia as being at risk for inundation by woody debris. The second map (middle) displays the prioritization of micro-watersheds that will potentially impact the acequias, with the pink box identifying the area that is covered in the zoomed-in map on the right (third map). While it is good to know which reaches of each acequia are under threat, it's also crucial to understand the contribution of threats from the upslope areas. The third map depicts a subset of at-risk acequias, and includes an analysis of which hillslopes will potentially impact each waterway to the greatest degree.

Mapping Sequence 6, below. We can also analyze risks to acequias or other values by looking at the distance from the value (here it's each acequia) to the least stabile (highest threat) areas on the landscape. In the maps below, the left shows the acequias as blue lines, and the hillslopes in different colors ranging from red to green. The red and orange colored hillslopes indicate high-threat (in need of stabilization for soil and/or woody debris) areas that are within 3 miles of an acequia. The light-green to dark-green colors reveal high-threat areas that are farther than 3 miles from an acequia. The map to the right is a zoomed-in view of where the purple box is on the left map.

We've compiled several different Values At Risk maps, showing distance from zones in need of stabilization. Those include: physical structures (houses, barns, etc), acequias (shown), waterbodies (such as Storrie and Morphy Lakes), county roads, state highways, ditches, and so on. Those are all being used in the NRCS EWP response to determine conservation and stabilization needs and priorities.

Mapping Sequence 7, below. Here, the left map shows the entire burned area with structures identified as blue dots. The hillslope coloration in both the left and the right (zoomed-in) maps reveal distances to high-threat areas, which indicate high concerns related to the burn severity and potential hazard of soil erosion and/or woody debris flows. The deeper the red/orange color, the closer a structure(s) is to a potential threat (less than 3 miles away). As the colors shift to green, the potential threats are farther away (greater than 3 miles). This type of mapping can help NRCS prioritize the emergency response needs.

Mapping Sequence 8, below. Now that the watersheds at risk, structures, acequias and other values at risk have been combined, the analysis shifts into a predictive modeling mode. Being that the most pressing post-wildfire hazards are typically water-related, the left map shows the 20-year average precipitation in the region from July to September (source: DAYMET, downscaled from 1km to 10m). The strong monsoonal rainfall pattern is evident with the amounts shown.

The map on the right is the modeled post-fire debris flow impact, which is influenced by precipitation amount, burn severity, soil k-factor, slope, and the accumulated hydrologic areas. All maps will be refined once the LiDAR data informs us of the amount and kind of woody debris on each slope.

All of the maps above were produced using publicly-available data. The first phase of this emergency response was to provide maps and associated spatial data to the NRCS teams on the ground, within 7 days, to help them triage potential hazards and degree of risk. Phase One was completed 7 days after project funding was provided.

The Phase 1 maps represent the basic building blocks, and have been critical to the teams on the ground in assessing damages, threat areas, and stabilization needs. When Phase 2 began 8 days after project funding, we used the "gee-whiz" technology to drive very detailed spatial assessments including soil loss amounts, estimates of woody debris volumes/kinds, potential culvert and bridge impacts, and so on. The maps in Phase 2 were created using 40cm LiDAR and 15cm 4-band imagery (blue-green-red-infrared). Those data were collected, processed and analyzed by Teren Inc., specifically for this project.

Phase 2 also uses the Climate-Enhanced Topographic Wetness Index (CETWI). This is a terrain model using associations of multiple environmental variables to determine surface moisture potential and hydrologic flow paths under different climate realities (actual data or climate-change scenarios). Teren Inc. is the developer of CETWI, under an agreement with CEAP-Grazing Lands, to meet the needs we have for modeling these very diverse ecological systems. CETWI is almost completed for the Western U. S. and a publication and data transfer to NRCS are pending. Using CETWI as a main foundational layer in the Hermits Peak assessment allows NRCS to identify areas where erosion control structures and conservation plantings will be most successful. With the potential damage to the acequia system, knowing where to plant if irrigation water is not available will be essential.

It's important to understand the resolution and scalability of different products, such as the digital elevation data, LiDAR, imagery, and so on. Very fine resolution (less than 1 meter) products offer countless opportunities to assess large landscapes at field-relevant scales for conservation and management alternatives. The more coarse resolution (greater than 10 meter) products lend themselves to regionally-relevant, but not field-relevant scales. With the goals of EWP being to protect life and property, the fine resolution field-scale products are essential.

Mapping Sequence 9, below. The image on the left is a 10 meter national elevation hillshade dataset product (NED), and is a very common data product used. The horizontal and vertical lines and image blurriness as a user tries to zoom into (change the scale) this coarse resolution product are obvious and cannot be digitally-removed. However, the image to the right is a 40cm resolution LiDAR hillshade product of the same area and zoom-scale. The right image is clear and highly detailed, offering NRCS the opportunity to assess field-scale post-wildfire threats that can be mitigated and treated.

Mapping Sequence 10, below. The NRCS "job", with respect to both emergency response (EWP) and conservation planning, is to clearly identify where potential hazards and resource concerns exist, and to quantify them as accurately as possible. The images below show areas on the landscape where impacts of woody debris flow may be the greatest, and thus in need of treatment to offer protection from those debris flows. As shown in Mapping Sequence 9, the image on the left represents the woody debris flow threat using the NED 10m hillshade product. The image on the right represents the threat of woody debris flow using the LiDAR 40cm hillshade product. The resolution of the LiDAR product is considerably more detailed and offers NRCS the ability to identify and treat the essential threat-prone areas, rather than the treating the whole area. This results in lesser cost and more precision, while greatly reducing the potential threat.

Use the swipe tool provided in the frame below to see what is gained with a high resolution analysis. Low resolution (10m NED) on the left; high resolution (40cm LiDAR) on the right:

Water is essential to life. While high resolution data was one foundation of the Hermits Peak EWP response, we also analyzed water flow patterns across the burned area, and where moisture would collect or remain on the surface or in the soil profile longer.

The wildfire was still burning well into the normal monsoon season for northern New Mexico. With soils now bare and hydrophobic from the fire, the threat of ash, woody debris and rock flows was high, as shown in Mapping Sequence 10. The typical remediation measures after any wildfire include applying mulch and/or seed, building erosion control structures, slowing water and sediment with erosion control "sausages", and removing hazardous trees and debris. The NRCS and Teren Inc. worked together to develop the Climate-Enhanced Topographic Wetness Index (CETWI) model to identify areas with greater terrain moisture potential where vegetation seeding would be most effective. CETWI uses precipitation, evaporation, slope, aspect, solar radiation, curvature, flatness and other terrain features to identify water flow paths, ponding, and relative moisture duration periods across the landscape. The NRCS soil mapping products were then combined with the CETWI terrain moisture potential map, and the first "environmental triage" map was born for Hermits Peak.

The intersection of a high risk area with a high CETWI value provided the first level of triage for resource treatment to protect life and property.

The next mapping sequences reveal how the NRCS emergency response was informed by high resolution data, the CETWI model, and quantitative estimates of debris flow, sediment yield, hazard trees to harvest, and so on. The analysis included effects to "values at risk", including the acequias, homes/buildings, infrastructure such as roads, cell towers, bridges and culverts, and water bodies including streams and lakes. Much of the "values at risk" mapping is not provided in this story map, due to private property rights and data confidentiality. NRCS and partnering agencies are still working with landowners to rebuild the network of acequias and other values.

Mapping Sequence 11, below. Although the images below are not aligned 100% like the paired images in earlier mapping sequences, they do share part of their focal areas in common. The image on the left was shared earlier, and is the 40cm LiDAR hillshade. The image to the right is also 40cm LiDAR hillshade, but the coloration reveals the indexed Climate-Enhanced Topographic Wetness. Blue and green colors indicate areas where moisture will collect (blue; e.g., streams, rivers and lakes) and receive and retain moisture longer than surrounding areas (green; e.g., less steep slopes, north-facing slopes, and slopes shadowed by neighboring mountains) across the natural terrain. As the color palette warms to brown, yellow, orange and red colors, those indicate areas where moisture is shedding and/or evaporating quickly. These warmer-colored areas shed their moisture onto the green and blue areas if the moisture doesn't enter the soil fast enough to remain in place.

Why is this CETWI coloration important and helpful while assessing the burned area for different treatments that protect life and property? In a nutshell, it speeds the process, and reveals areas where one kind of treatment would be more successful than another. It results in a dollar-savings, and more acres in need can be treated with the savings realized. Normally, on an emergency rapid-response, there is not time to differentiate between areas that are suited only to seeding or only to mulching. Usually, seed and mulch are applied across the entirety of severely burned landscapes.

Mapping Sequence 12, below. The three images below are of the same general area. The left image is the most zoomed-out (coarser scale), while the middle and right images are the same scale. The left and middle images show CETWI wetness values in their coloration. The middle is an area that has been zoomed-into (finer scale) from the left image. All three images show treatment polygons (black and white boundaries) for "Seeding and Mulching" (black) or "Seeding only" (white). The right image coloration shows the burn severity, provided by U.S. Forest Service, of the same area as the middle image, with the treatment polygons also overlain. This treatment, CETWI and burn severity analysis was performed by Teren Inc. and NRCS CEAP-Grazing Lands in less than one day, for the entire burned area. For an area of this size without the high resolution (LiDAR), the CETWI model, it would have taken several weeks and numerous experts in the field to determine the extent and kind of treatment areas. Having these tools offers a huge savings in time, labor and the purchase and distribution of the right treatments.

Use the swipe tool below to see the CETWI wetness values (left) and soil burn severity degree (right) align with the recommendation of two different treatment types ("Seeding and Mulching", black polygons; "Seeding only", white polygons). Keep in mind that the NRCS soil map contributed to the location of different treatment types also, but is not shown here. For example, if a soil map unit contained exposed rock (no soil) within its boundary, we would not apply seed or mulch to bare rock. Similarly, if the soils were very shallow and burn severity was was moderate or high, no seed was applied because the failure rate would be high. In those cases, mulch could be applied. The fact that CETWI incorporates precipitation and evaporation into the model also provided a "treatment effectiveness" approach we were able to use. So in areas where soil depth was not an issue, but burn severity was high and CETWI values low (aka, "dry"), the treatment type was likely mulch, but not seeding, due to the anticipated failure rate of the seed establishing in those harsh areas and providing soil stability. For those areas, mulch was the optimal treatment choice.

For those who have never visited the Southern Rocky Mountains and the Hermits Peak area, it's important to know that much of the area was forested prior to the wildfire. Trees were long-lived and generally healthy, with little to no diseases or death from pests or other reasons. Generations of the same family lived throughout the mountainous areas and at lower elevations in the shadows and rivers provided by the mountains. Livestock allotments were well-established by the U.S. Forest Service and managed by those who leased the allotments and followed the allotment management plans provided by the Forest Service to protect the resources and allow for multiple use. After the Calf Canyon and Hermits Peak wildfires merged into the one known as Hermits Peak, the damage to established tree species was significant. The need to remove those hazardous trees was an essential aspect of the emergency response, plus future conservation efforts. NRCS CEAP-Grazing Lands, New Mexico NRCS and Teren Inc. worked together to develop a model that would capture the degree of burn impact to each tree. Yes, each and every tree in the burned area. Mapping sequence 13, below, shows that degree of impact to each tree, for a significant part of the burned area. This was performed mainly through use of the 40cm LiDAR data, but also using the 15cm color infrared imagery that was obtained before the fire was 100% contained, but after fire suppression occurred in the forested areas.

Mapping Sequence 13, below. The image below is actually a coarse-scale map of the burn severity experienced by each and every tree in the burn area. If a fine-scale map was shown, the coloration is really a series of independent "dots", where each dot equals one tree. The warm colors (red, orange) reveal "high" or "moderate" burn severity. The cooler colors (yellow, green) reveal "low", "very low", or "no" burn impact to the individual trees. This tree severity mapping was the first step in locating areas where hazardous tree removal was necessary.

Once the burn severity of each tree, and the forest as a whole was mapped, Teren Inc. and NRCS ran spatial analysis to determine tree removal methods and staging areas for both ground- and aerial-removal activities. We also estimated the volume of woody material, in cubic-feet per acre, that could be removed. The volume estimates were important to know if the harvested materials would be sold to businesses to create timber, pulp, and/or mulch off-site.

Mapping Sequence 14, below. In the swipe tool, the image on the left is the same tree burn severity map from Mapping Sequence 13, but is zoomed-into a particular area of interest. You can actually see the individual "dots" that represent each tree and the burn severity associated with it. The image on the right shows the existing roads (black lines) and relative amount of timber that could be harvested for mulch material (cubic-feet per acre) from each differently-colored polygon. The legend for the image on the right is provided below the swipe tool.

The volume of mulch (trees) that was estimated for extraction was limited by the existing road network shown in the right image. Hazard tree extraction was assumed to be possible within a 1-mile distance from existing roads. The volume was also limited by the number of accessible trees and their degree of burn severity. For example, trees with low/no burn severity (green and yellow dots in left image) offered low or very low cubic-feet per acre mulch materials (green and blue areas in right image), because it was assumed those trees would not be harvested.

Mapping Sequence 15, below. We also used all of this great technology, analysis and modeling to recommend where "staging areas" for the hazardous tree removal activities could be reasonably located. A staging area is where the harvested trees are placed temporarily, until they can be hauled off-site for processing, or mulched on-site and moved to areas in need of soil cover to minimize erosion. The staging areas are large enough for heavy machinery to operate between the stacks of harvested trees, to load them onto haul trucks, or have them lifted out by helicopter, or as already mentioned, grind certain size trees and branches into mulch. Terrain slope, soil depth, soil texture, rockiness, drainage pattern, and other considerations are factored into determining the best staging area locations. The image on the left, below, was also shared in Mapping Sequence 14. It shows where hazardous trees can be extracted along the existing road network, with the colors of each polygon indicating an estimated volume of mulch that those areas would yield (cubic-feet per acre). The right image adds purple crosshatching within those potential harvest areas, showing where suitable staging areas could be located.

Thanks to technological advancements, we worked hand-in-hand with Teren Inc. and New Mexico NRCS to produce all of the triage assessments and maps shared in this story within 9 weeks after President Biden's disaster declaration. This rapid and thorough response by NRCS, to the largest wildfire in New Mexico's history, is unprecedented. The data, analysis, and conservation achievements continue to this day, with New Mexico NRCS and Teren Inc. working together with private landowners. Though the immediate emergency has passed, the needs are still great.

At this writing, it has been over 12 months since the Hermits Peak fire was fully contained on August 21, 2022. Communities are still working to repair their resources, livelihood and families. A new partnership with the Federal Emergency Management Agency (FEMA), under the  Hermits Peak Fire Assistance Act (Sept 30, 2022) , brings an additional $3.95-billion to those affected by the Hermits Peak wildfire. FEMA is collaborating with New Mexico NRCS, Teren Inc, and many others to provide much-needed and ongoing assistance. All of the "values at risk", including restoration of acequias, and "threat/hazard" maps developed in those first 9 weeks of NRCS emergency response are still being leveraged today, helping target FEMA's $3.95-billion toward specific expenses incurred by landowners during and after the tragedy. For additional information from FEMA, there are several news videos and a YouTube Channel to assist those affected:

 KOAT Channel 7 reports on FEMA restoration plans   FEMA Region 6, Hermit's Peak Calf Canyon Fire YouTube Videos 

For current information on NRCS conservation and restoration efforts within the Hermits Peak affected area, and to seek NRCS assistance, please view:

 USDA NRCS Hermits Peak/Calf Canyon Conservation Restoration Plan. 

All completed mapping products and data were supplied to NRCS as geospatial data, and are uploaded into the ESRI Field Maps application for use by NRCS conservationists and NRCS first-responders. This allows instant access and continued communication between NRCS and Teren Inc. If new mapping or hazard determination needs arise, Teren Inc. and NRCS are ready to respond.

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