There is a long-standing interest in the interactions between hydrological processes and the deformation of the solid Earth, including earthquakes. This talk will highlight recent advances in geodesy that allow us to monitor the spatial and temporal changes in continental water storage over seasonal to decadal time scales and how they deform the Earth. We will explore various implications of these observations, including probing the Earth’s mechanical properties, such as the mantle’s transient rheology and the hydromechanical properties of aquifers, or advancing our understanding of the seismic cycle. These findings have significant implications for addressing pressing scientific and societal challenges, including gaining insights into the physical processes associated with Earth deformation and the earthquake cycle, and developing strategies for sustainable water ressources management.