The Great Salt Lake reached record low volume 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. Increasing evaporation due to climate warming also accounted for a substantial proportion of the departure. Results suggest that increased streamflow can lead to rapid volume recovery, but under continued warming, evaporation is expected to lead to additional water loss.