Explaining the 2022 record low Great Salt Lake volume

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 model that simulates lake volume change. We perform four simulations, one where inputs and output roughly equal each other to reach an “equilibrium volume”, and three others where we allow one input or output variable to follow observations while the other two remain fixed at their equilibrium mean. Results show that unusually low streamflow played the largest role in the record low volume in 2022, accounting for 2/3 of historic water loss while increasing evaporation due to climate warming accounts for roughly the rest.

Publication
Bigalke, Siiri, Paul Loikith, and Nicholas Siler. "Explaining the 2022 record low Great Salt Lake volume." Geophysical Research Letters 52.2 (2025): e2024GL112154. https://doi.org/10.1029/2024GL112154

This work was supported by NSF Grant AGS-2206997.

Lake volume, inputs, and output change leading up to the record low

Time series of annual (a) GSL volume and surface area, (b) precipitation at SLC and Tooele stations, (c) total volumetric streamflow of the Bear, Jordan, and Weber Rivers, (d) air temperature anomalies (with reference to 1991–2020 period) at SLC station, and local evaporation rate over the lake. The thick green bar in (a–d) shows the time period used to calculate the equilibrium period mean (1951–1977) and the numbers inside the bar are the mean used to compute the equilibrium volume. The solid purple line in c is the primary Bear River station, the dashed purple line is the Bear River station 48 km upstream.

Annual water contributions from lake inputs/output

(a) Observed (dashed black line) and the control simulated (solid red line) lake volume (in km3) from 1949 to 2022 and annual input and output contributions from 1950 to 2022 shown as absolute values in km3. The control simulation is initialized using 1949 data for the 1950–2022 simulation. (b) Observed year-to-year volume changes (black bars), estimated year-to-year volume change calculated by subtracting annual evaporation from the sum of annual precipitation and streamflow (gray dash), and simulated year-to-year volume change from the control simulation (red star). WDPP time period used in our model is shown in gray shading in (a–b).

Model simulation results

(a) Results of model simulations of annual lake volume with (b) year-to-year water contributions for each simulation. An upward pointing arrow indicates water was added to the lake and a downward pointing arrow indicates net water loss during that year. (c) The difference in 2022 volume compared to equilibrium volume level in 2022. The gray shading in a-b represents the years spanning the West Desert Pumping Project.

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