Snowpack was good in winter 2019/2020 so why did our rivers get low so early? The snow melted early and extraordinarily quickly this spring. This along with a combination of effects from a rapidly changing climate are colliding to cause dramatic shifts in how water interacts with our landscape.
The United States Geological Survey, the federal agency responsible for providing public scientific studies on the effects of natural disasters, has found that snowmelt is coming 2-3 weeks earlier on average in the Colorado Rocky Mountains. A warm, dry fall in 2019 followed by record high temperatures in early spring, 2020 combined with deposits of dust from deserts to the south and west of us caused our snow to melt very quickly. The extended megadrought we are in means that soils and other water storage were already very dry. Additionally, fewer months of snow on the ground means a change in albedo and evaporation which have led to even more loss of water from the Colorado River.
CITATIONS & STUDIES
Colorado Stream Flow, USGS https://waterdata.usgs.gov/co/nwis/current/?type=flow
Increasing aeolian dust deposition to snowpacks in the Rocky Mountains inferred from snowpack, wet deposition, and aerosol chemistry;David W.ClowaMark W.Williams and Paul F.Schuster: https://doi.org/10.1016/j.atmosenv.2016.06.076
Colorado River flow dwindles as warming-driven loss of reflective snow energizes evaporationScience 13 Mar 2020: Vol. 367, Issue 6483, pp. 1252-1255. DOI: 10.1126/science.aay9187
