Groundwater is a vital source of freshwater worldwide, helping sustain river flows during droughts and supporting areas with shallow water tables. A new global-scale groundwater model was developed to study groundwater depletion. By including confined aquifer systems, the model showed changes in groundwater flow paths and interactions with surface water. The model estimated a global groundwater depletion of 6700 km3 from 1960 to 2010, highlighting the importance of considering different aquifer systems in understanding groundwater dynamics.