Executive Summary - Resources & Threats Identified By Las Conchas BAER
Incident: Las Conchas Burned Area Emergency Respon Burned Area Emergency Rehabilitation
Released: 7/21/2011
Executive Summary
Resources and Threats Identified by the Las Conchas BAER Assessment
Santa Fe National Forest
The Las Conchas fire started on June 26, 2011. The fire is located on portions of the Espanola, Coyote, Jemez Districts of the Santa Fe National Forest, Bandelier National Monument, Los Alamos National Laboratory, Los Alamos County, Valles Caldera National Preserve, Jemez Pueblo, Santo Domingo Pueblo, Santa Clara Pueblo, and numerous private inholdings. The fire was situated in an area bounded by the Sierra De los Valles to the east, on the western side by the Pajarito Plateau, Polvadera Peak to the north and Cochiti on the south. As of July 16, 2011, the fire had burned more than 150,000 acres with large patches of high and moderate severity burns. The size and intensity of this fire has resulted in considerable threats to life and property, natural resources and created values at risk.
Currently there is an unacceptable risk, particularly in regards to life and property related to watershed response. Post-fire discharge calculations range between 280 and 3600 cfs. Within the burn perimeter, critical values at risk were identified in 6 of 33 watersheds. Values at risk were evaluated using a risk matrix. Bland and Cochiti drainages were found to have the greatest risks with calculated maximum runoff estimated at 1900 and 3200 cfs respectively. Bland Canyon contains a historic mining district that poses risk of debris jams at road crossings and contamination of flood waters. Cochiti Canyon contains state land and lease-holder facilities and assets such as the Dixon Apple Orchard.
Approximately 23% (28,470 acres) of the fire burned with high severity and 25% (39,910 acres) burned with moderate severity. Combined, the high and moderate severity accounted for 48% (68,380 acres) of the burned area. From a soils and watershed condition standpoint, these burned acres will account for a majority of the erosion and sedimentation in the burned area. In high burn severity areas soils may become water repellent (hydrophobic tendency) that impacts the potential runoff hazard and predicted sediment production of the burned area. Results of hydrophobicity tests from 30 sites throughout the burn area indicate highly variable soil conditions. Even though there may be somewhat limited fire induced hydrophobic tendency within the burn (30-40% of moderate and high burn severity with the aerial extent), watersheds will realize significant increased hydrologic response and loss of control of water. The soil hydrophobic tendency in areas of high and moderate burn severity may result in emergency conditions such as loss of control of water, particularly in drainages of Frijoles Canyon, Cochiti Canyon, Medio dia Canyon, Bland Canyon, Peralta Canyon and Santa Clara Canyon; accelerated soil erosion; potential flooding, sedimentation and debris flows and torrents onto private properties below areas of the burn; and loss of long-term site productivity.
Eight roads were identified that had potentially critical values at risk. Treatments to address threats to life and property were identified for these priority roads and include removal of hazard trees, culvert cleaning or removal, posting warning signs for flooding and falling rock hazards, installing gates, closing areas, and addressing road drainage issues.
As a result of the fire's severity and extent, little can be done to mitigate losses to wildlife and fisheries resources. Fire effects to the Mexican spotted owl (Federally listed) and Jemez Mountain Salamander (Federal candidate species) may result in the long term loss or reduced habitat suitability for both species.
Four populations of Rio Grande cutthroat trout (USFS Region 3 Sensitive Species and Federal candidate species) are within the burn area. Of these populations, one is a recreation population (Peralta Canyon), two are conservation populations (Medio Dia Canyon and Rio del Oso and tributaries), and one is a core population (Capulin Creek). Because of the size, severity, steepness of slopes, and proximity of the wildfire aquatic habitats and Rio Grande cutthroat trout are at a very high risk of impact. Impacts include changes in peak flows and deposition of ash and sediment which negatively alter fish and macro-invertebrate habitat and water quality. Fish deaths due to fire are also associated with ash flows, which can obstruct gill membranes and cause asphyxiation.
Cultural and archeological resources are abundant within the area burned by the Las Conchas fire. Values at risk include sensitive and irreplaceable Traditional Cultural Properties for the Pueblos of Jemez, Santa Domingo, Cochiti, San Ildefonso, Santa Clara, and Ohkay Owingeh; irreplaceable archeological sites of tremendous scientific and cultural significance; and historic sites of both Puebloan and non-Puebloan origin.
Recreation values at risk include the Dome Wilderness, East Fork of Jemez Wild and Scenic River, 100 miles of trail, developed recreation sites such as trailheads and picnic areas, Pajarito Nordic Ski Trail, and views along the State Road 4 Scenic Byway.
Changed environmental conditions resulting from the fire are conducive to non-native invasive plant species (NNIS) introduction and establishment, especially areas of high and moderate burn severity. NNIS can dramatically reduce biodiversity, alter ecosystem processes that provide surface water and benefits to other natural resources, reduce habitat and forage for native wildlife, increase soil erosion, and change the fire return interval. These alterations are not easily healed. Depending on the scale, duration, and frequency of the invasion, restoring the ecosystem to its original condition may not be technically or financially feasible.
Ten National Forest System grazing allotments and the Chicoma Wild Horse and Dome Wild Burro Territories are wholly or partially within the burned area. The area within each allotment that was affected by the Las Conchas fire and the degree of the burn severity was variable for each of the allotments. In addition, range structures such as fences and water developments may have been directly affected by the fire or are likely to be affected by post-fire run off events.
Treatments proposed to minimize values at risk include:
· Removing culverts and installing structures to protect culverts or road segments.
· Clearing stream channels.
· Addressing flooding issues associated with toilets at the Las Conchas Picnic Recreation Area.
· Install hazard warning signs about potential flood and debris flow danger.
· Seeding and mulching around the Pajarito Nordic Ski Trails.
· Protecting cultural sites with tree removal and mulching.
· Installing gates to close the forest within the burn perimter.
· Repairing or replacing the Abrigo repeater on VCNP.
· Remove hazard trees and rocks from roads and other treatment areas.
· Notifying local government officials about the post-fire flood risk through certified letters.
· Remove the recreation bridge on Peralta Creek.
· Stabilize recreation trails in order to minimize erosion from post-fire runoff.
· Seeding in two watersheds with considerable amounts of high and moderate burn severity.
· Mulching in high and moderate burn severity within Bland Canyon.
