USING THE GRACE SATELLITES AND GROUND-BASED DATA TO ASSESS GROUNDWATER STORAGE CHANGES IN THE SOUTH PLATTE BASIN, COLORADO

The growing need for water among urban users, agriculture, industry, ecosystems, and energy development, presents challenges in water-limited systems. Lack of adequate temporal and spatial groundwater data can limit our ability to fully understand the stresses that different water users place on aquifers. We estimate groundwater storage changes in the South Platte Basin by comparing GRACE derived storage changes with ground-based data. Short-term and long-term groundwater storage changes for the Denver Basin Aquifer System and the South Platte Alluvial Aquifer are investigated. The effectiveness of GRACE to help better understand smaller-scale, regional groundwater systems is evaluated. Results indicate that GRACE may be useful for managing and understanding groundwater resources over the South Platte Basin and can help reduce uncertainty due to missing spatial and temporal groundwater data. Comparison of groundwater levels for the two aquifer systems are consistent with the increasing and decreasing patterns detected by the GRACE satellites. This work highlights the need for increased groundwater level data and monitoring within the basin and provides additional information about the application of GRACE at smaller scales for evaluating groundwater resources.