The GeoERA-RESOURCE project (http://geoera.eu/projects), part of a H2020 ERA-NET aims at demonstrating the potentials of harmonized hydrogeological information, 3D structure of aquifers, the water volumes available, and the water fluxes across state borders to support transboundary groundwater management. It has a lot common with DARLINGe aims to support the enhanced use of transboundary geothermal energy resources, of which the carrying medium is thermal groundwater, and numerous  cross-border geothermal aquifers and regional flow systems have been identified. The 2 projects held a joint cross-fertilization workshop on February 21 in Budapest at the Mining and Geological Survey of Hungary, where experiences in methodology and implementation of data harmonization related to cross-border (thermal water) aquifers were shared and jointly discussed. 25 people from 17 European countries representing the 2 projects attended the workshop.