Single Publication

USGS Models Show High-Level Debris-Flow Hazards for Phase II

Hermits Peak-Calf Canyon Burned Area

BAER SAFETY MESSAGE: Everyone near and downstream from the burned areas should remain alert and stay updated on weather conditions that may result in heavy rains and increased water runoff. Flash flooding may occur quickly during heavy rain events. Be prepared to act. Current weather and emergency notifications can be found at the National Weather Service website:  www.weather.gov/abq/.

The Forest Service (USFS) Burned Area Emergency Response (BAER) assessment team coordinated early with US Geological Survey (USGS) staff during its evaluation of the Hermits Peak-Calf Canyon Fire burned area to strategically assess potential post-fire impacts to the watersheds and predicted debris flow response during damaging storm events.

The USGS debris flow assessment report indicates a high-level debris flow hazard for most of the area assessed in Phase II of the BAER assessment of the Hermits Peak-Calf Canyon fire. Most stream reaches and small drainage basins have a greater than 60% likelihood of debris flow occurrence at a modest rainfall intensity of 24 mm/h.  Debris flow likelihood exceeds 80% in a few drainage basins at this 24 mm/h rainfall intensity.  A rainfall intensity of 24millimeters/hour equals .9inches/hour.

These high to very high hazard areas are widespread in the Phase II assessment area, including above County Road A023 near the Rincon Mountains, Vigil Canyon, some sections of New Mexico Highway 276, County Road C001 near Fragoso Ridge, and County Roads A3a and A4a in the southern portion of the assessed area.  There are numerous other high hazard areas not mentioned in this summary.

The USGS model predictions represent estimates based on free, readily available data.  Certain local conditions not represented by the input data may significantly impact site-specific debris flow hazard.  In addition, USGS models only consider debris flows.

Flooding, including sediment-laden flash floods, is not considered in the model.  Please visit: https://www.usgs.gov/programs/landslide-hazards/science/scientific-background?qt-science_center_objects=0#qt-science_center_objects for limitations of the modeling approach. 

The online interactive map is posted at https://landslides.usgs.gov/hazards/postfire_debrisflow/detail.php?objectid=419.

Click on the button at the top right corner of the map to show different components of the hazard assessments.  Zoom in if the map does not immediately load.

Visit the following link for Scientific Background and more information on how the predictions are calculated: