Scaling Down: Unveiling Heterogeneity In Arizona'S Groundwater Landscape
Presenter: Danielle Tadych P231
Co-Author(s): Laura Condon, Bonnie Colby
Advisor(s): Laura Condon
1Hydrology & Atmospheric Sciences
Arizona is an interesting case study for groundwater management due to the complexity of groundwater legislation, land use, and access to surface water. For this study, we zoom into areas with different land use, groundwater management, and social or legal controversies to determine groundwater trends and drought responses of these areas. We downloaded data from groundwater monitoring wells for the period 2000-2022 and filtered to include wells with 15 years of data or more. Linear trends, anomalies, and maximum drawdown for each study area were calculated. State averaged Palmer Drought Severity Index was used to determine severe droughts. Our results show that urban regions of Tucson and the Phoenix are experiencing less severe drought responses and increasing groundwater levels since 2000. Flagstaff did not show any relationship to drought, but has experienced significant groundwater declines of greater than 200 feet. Yuma, a highly agricultural region with direct access to Colorado River water, shows the least severe drawdown but slightly decreasing groundwater levels over time. However, high priority groundwater subbasins identified in the Arizona Governor’s Water Policy Council Report (Ranegrass, Gila, and Wilcox) showed the largest decreases in groundwater and the worst drawdown during severe droughts. Wilcox recorded a staggering 26-foot drawdown during the 2021 drought. These areas are predominantly groundwater dependent but have had increased agricultural activity in recent years, having concerning implications for future sustainability. Overall, our results highlight the importance of studying groundwater dynamics at smaller scales, enabling more tailored and effective groundwater management decisions.