Explaining the 2022 Record Low Great Salt Lake Volume

Abstract

The Great Salt Lake reached the lowest water volume in its entire 170+ year record in 2022. To explain this record low we develop and apply a lake mass-balance model and perform four simulations: one where all input and output variables are fixed to their mid-20th century average resulting in an equilibrium lake volume, and three others where one of the input variables (precipitation or streamflow) or the output variable (evaporation) follows observations while the other two are fixed to their mid-20th century average. Results show anomalously low streamflow accounting for the largest proportion of the lake volume departure from the equilibrium state by 2022, resulting in about three times the additional water loss over 1950–2022 as increasing evaporation, which played the second largest role. Precipitation changes played a minimal role. Though streamflow had a greater effect, the lake would not have reached the record low volume without increasing evaporation.