This presentation will provide an overview of water management challenges in the Great Salt Lake Basin, summarize GSBLS study objectives and modeling framework, and characterize current and projected hydroclimate conditions across the basin. The Great Salt Lake Basin Study (GSLBS) aims to evaluate adaptation and mitigation strategies to improve the resilience of water management under uncertain future climate conditions. To achieve this aim, the GSLBS modeling framework integrates downscaled future climate projections with a hydrologic model, water demand model, and RiverWare planning model to simulate water supplies, demands, and management across the basin. The modeling framework will be used to evaluate the effects of changing hydroclimate conditions, population growth, and other factors on water supply reliability and other performance metrics. The modeling framework will subsequently be used to evaluate potential improvements in system performance from selected adaptation and mitigation strategies.

Characterization of future hydroclimate conditions is an essential component of the Basin Study. An ensemble of 101 statistically downscaled climate projections was developed from 27 General Circulation Models (GCMs) using the Multivariate Adaptive Constructed Analogs (MACA) method. Preliminary analysis of this ensemble will be presented for a suite of hydroclimate metrics identified in collaboration with the study partners along with principal component analysis (PCA) of dominant modes of hydroclimate variability and generalized extreme value (GEV) analysis of hydroclimate extremes. These results quantify projected changes in temperature and precipitation, including changes in the magnitude and persistence of extremes, and provide a systematic basis for identifying representative hydroclimate scenarios that span the range of plausible future conditions.

This GSLBS modeling framework provides a transparent and reproducible approach for translating hydroclimate uncertainty into planning-relevant information to support robust adaptation and mitigation strategies for the Great Salt Lake Basin.