GROUNDWATER DYNAMICS AND CONTRIBUTIONS WITHIN THE ASHLEY-BRUSH BASIN, UTAH

Communities are dependent on water accessibility and availability and as such, declining water resources have drastic consequences. Effective and informed water use practices are critical due to the broad ramifications of water deficits that may become more pronounced with a changing climate. The Upper Colorado River Basin (UCRB) is a hydrologic region that spans the states of Colorado, New Mexico, Utah, and Wyoming. Small-scale subbasin models constraining the groundwater dynamics of the UCRB are thus crucial for resource allocation in times of increased water consumption and pronounced climate variation. The Ashley-Brush Basin in Utah is a watershed located within the UCRB that is dependent on the snowmelt-driven Ashley Creek to support municipal and agricultural water demands. However, previous investigations of the Ashley-Brush Basin have lacked quantification of groundwater resources within this semi-arid region over time.

In this study, we assess the Ashley-Brush Basin using MODFLOW, to constrain the subbasin’s groundwater availability for land management decisions in a changing climate. We hypothesize that rising temperatures and growing consumption demands produce an increased reliance on groundwater in water budgets over time. While the Ashley-Brush Basin is a relatively small watershed within the overall UCRB, detailed understanding of the water use and management of subbasins within major hydrologic units are key pieces of information to the larger puzzle. Complex watersheds such as the Upper Colorado River Basin present significant challenges in planning future water budgets and resource management.