In order to build confidence in describing the hydrological cycle under future global change, hydrological models not only need to be calibrated and validated with recent data, but should also be tested against different boundary conditions fromthe past. This requires building a dataset of hydrological state variables againstwhich the modelling output can be tested. We use pedogeomorphological and historical data to monitor hydraulic heads at specific time slices during the last 500 years for a sandy interfluve in the Nete catchment, NE Belgium. The nature of the archive is temporally and spatially highly discontinuous but allows to observe a systematic drop in phreatic groundwater levels during the second half of the 19th century. It is concluded that the approach yields promising results and that it might be of use elsewhere in drift sand landscapes across the European sand belt.