Exploring Groundwater Drought Response Through The Lens Of Groundwater Regulation And Surface Water Availability In Arizona
Presenter: Danielle Tadych1
Co-Author(s): -
Advisor(s): Dr. Laura E. Condon
1Department of Hydrology and Atmospheric Sciences, University of Arizona
Arizona is an interesting groundwater case study because of its diversity in groundwater regulation, access to surface water, and long history agriculture despite continuing long-term droughts. For this study we looked at Arizona through two lenses: (1) State regulated or unregulated groundwater use, where regulated areas have groundwater permits and withdrawals limited by the state, and (2) relative access to surface water sources either directly or by the Central Arizona Project Aqueduct. Groundwater datasets from Arizona and satellite CSR-GRACE data are used in this study to determine storage changes and depth to water readings during times of drought. Palmer Drought Severity Index was the primary drought indicator for correlation analyses and a threshold was set to designate severe droughts. Results show severe droughts are having worsening effects on groundwater. Unregulated and completely groundwater dependent areas have greater depth to water anomalies in recent severe droughts. Also drawdown is much greater in unregulated groundwater areas and areas with less access to surface water. Well data indicate areas with access to Colorado River water have better drought recovery times in recent years but GRACE data show storage recovery times are worse in areas receiving Colorado River deliveries and in southeastern groundwater dominated regions. These results have dangerous implications for the future of areas in Arizona receiving Colorado River cutbacks.