ScaldWIN is an Interreg IVB NWE project for a better quality of surface and groundwater bodies in the Scheldt International River Basin District (IRBD). This will be done by developing and implementing a set of cost-effective, innovative and transnational actions aimed at attaining a good status of surface and groundwater bodies. By monitoring the transnational effect of these actions, the foundation for the development of a transnational surveillance system for the Water Framework Directive (WFD) programmes of measures for the Scheldt IRBD will be laid.