Presentation description

Variability in groundwater storage under the Salt Lake Valley is driven by seasonal and multi-year cycles in climate. In the spring, seasonal snowmelt transfers surface water from the Wasatch Mountain range into the Salt Lake Valley to the west. Utah has a primarily dry, semi-arid desert climate that depends on this streamflow as a recharge event and a primary source of regional groundwater. Groundwater is a vital source of water for industry, agriculture, and human consumption in the western United States. As the population of Salt Lake County is projected to increase from the current population of 1.20 million to 1.33 million by 2060 and as climate warming is expected to continue, groundwater will become an increasingly scarce resource. An improved understanding of the role of climate-driven groundwater stores will be crucial for making informed water management decisions in the Salt Lake Valley. Existing estimates of direct groundwater inflows to the Great Salt Lake are primarily derived from water budget residuals (i.e. inflow needed to balance the water budget) and are therefore subject to significant uncertainty. While traditional hydrological observations are critical in the quantification of surface water supply, subsurface water storage remains difficult to measure. In this project, we obtained weekly microgravity observations at 7 locations in Red Butte Canyon using a Scintrex CG-6 gravimeter. These measurements were taken at previously existing hydrological sites, where baseflow and seismic velocity data can be correlated with gravity measurements. In this correlation, we aim to provide a faster and more accurate means of quantifying groundwater storage changes. This methodology will expand our understanding of how climate change impacts groundwater recharge on a multi-year scale and inform more educated water management decisions for the Salt Lake Valley.