Hydro(geo)logy has long advanced through empirical discovery, with Fundamental principles such as Darcy’s Law of flow through porous media and Theis’s well equation emerged from systematic observation before theory. These empirical advances remain cornerstones of modern hydrogeology. Yet, in recent decades, groundwater research risks stagnation by increasingly prioritizing “models of models”, opaque calibration routines, and parameterizations divorced from direct measurement. While models remain essential tools, one risk is that calibrated outputs may be interpreted too readily as truth, which can obscure the complexity of real processes. This has fostered a disconnect between modeled representations and the realities of groundwater fluxes in a world where pumping, contamination, human-driven climate change impacts and land-use change have rendered “pristine” aquifer systems rare exceptions. Against this backdrop, the paradigm of Whole Earth Hydrology (Gleason and Brown, 2025) calls for a reorientation: a return to discovery-driven, data-grounded, at scale, and human-inclusive hydro(geo)logy. This approach champions empiricism as a path toward truth-seeking, leveraging both field-based observation and satellite-derived datasets, while explicitly recognizing humans as inseparable actors in groundwater systems. We invite contributions that embrace empiricism in groundwater science—whether through novel field campaigns, innovative community-driven monitoring, or the use of emerging Earth observation platforms such as SWOT, GRACE, and high-resolution geospatial datasets. Equally welcome are studies that integrate human water use, infrastructure, and governance into groundwater assessments, treating humans as intrinsic elements of the aquifer systems. Submissions are encouraged across scales, from local groundwater–surface water interactions to regional aquifer studies and continental syntheses. By emphasizing “measurement before modeling,” this session seeks to highlight new empirical laws, large-scale observational syntheses, and cross-community collaborations that reveal truths about groundwater systems otherwise obscured by abstraction. Discussions will highlight how advancing groundwater science in the 21st century requires both technological innovation (e.g., artificial intelligence, remote sensing) and social integration (e.g., equity, Indigenous knowledge, participatory monitoring). The goal is to define a pathway toward a more holistic groundwater science—empirical, discovery-based, and rooted in data — while remaining responsive to the needs of communities, ecosystems, and policy.