New Mexico Geological Society Annual Spring Meeting — Abstracts

The Hermit’s Peak/Calf Canyon fire burned approximately 342,000 acres in San Miguel, Mora, and Taos Counties in northern New Mexico from April 6 through August 22, 2022. The fire started out as a US Forest Service controlled burn that quickly became uncontrolled. This uncontrolled burn resulted in the largest fire in New Mexico history, displaced hundreds of residents and livestock, and severely burned the Rio Gallinas watershed, the source of the City of Las Vegas, NM’s drinking water supply. Hydrologic effects include increased frequency of flashy runoff, increased sediment and ash flowing into the Rio Gallinas, and debris flows derived from ungauged tributaries. The increased ash and sediment load results in unpredictable periodic turbidity spikes that prohibit the City’s water treatment plant from diverting and treating water until turbidity in the river returns to treatable levels. Flash floods from intense localized storm cells over burned areas made the City’s primary storage reservoir unusable for several months in the summers of 2022 and 2024. Reservoir sedimentation associated with these flash flood events has reduced available storage in the reservoir by approximately 8%. The loss of forest canopy has resulted in earlier snowmelt and runoff and increased sedimentation during monsoonal rains. Hydrologic effects are anticipated to last years.