We hypothesise that by combining observations of satellite gravimetry, terrestrial gravimetry and Global Navigation Satellite System (GNSS) displacements, a more complete picture of the regional time-variable gravity field and of the underlying water storage variations can be obtained. The overall aim of this project is to develop models of regional time-variable gravity (or, equivalently, of total water storage variations) at uttermost high spatial and temporal resolution. The project tackles one of the most pressing challenges in geodesy and its dependent geophysical applications nowadays - the consistent integration of the various geodetic sensors and an increase in the temporal and spatial resolution in time-variable gravity field solutions and derived total water storage changes. In addition, absolute quantum gravimeters will be deployed for the first time in field campaigns. For gravity monitoring at the regional scale, we will capitalise on the fortunate situation that absolute and relative terrestrial gravimeters of various types will be available to this project, setting the ground for the next generation of gravimetric monitoring (networks) based on more flexible and precise technology.