The Potential of Landscape Scale Treatments to Reduce Sublimation Losses of Critical Water Supply Snowpack in the Western United States

A variety of treatments were tested for their effectiveness at limiting sublimation losses from snowpack. Treatments tested included vertical compaction, spraying the snowpack with a coating of vegetable oil, and applying a layer of chipped Ponderosa Pines slash biomass over the top of the snowpack. In meadow areas, untreated snowpack ablated at a rate of 0.66 centimeters of snow water equivalent (SWE) per day, while snowpack covered with a thick blanket of biomass ablated at a rate of 0.10 centimeters of SWE per day. Further, at the end of the data collection period, the control had lost 100% of its original SWE, while the biomass treated snowpack only lost 22% of its original SWE. In areas with a dense forest canopy, untreated snowpack ablated at a rate of 0.53 centimeters of SWE per day, and the snowpack treated with a thick biomass blanket averaged a loss of 0.20 centimeters of SWE per day. It was determined that a thick layer of biomass (about seven to ten centimeters in depth) would help reduce sublimation losses of snowpack in both meadow and canopied areas. A cost analysis was performed to determine the price of application of the thick biomass blanket, and it was determined that one application would cost roughly $365 per 4,047 square meters (1 acre). This high cost of application poses a real challenge to the feasibility of implementing this treatment to reduce sublimation losses at landscape scales.