The KI has instruments with a country wide distribution, which are able to register the changes in the groundwater level caused by natural or anthropogenetic effects. The instruments are built in wells. About half of these wells (83 pieces) are part of the National Basic Monitoring Register System with the scope to fulfill the requirements of the European Union’s Water Framework Directive (WFD). The chemical status assessment and characterization of groundwaters is also part of the system, due to the accredited water sampling group and the water sampling instruments. Beside these tasks 3 dimensional hydrogeological modelling are carried out to characterize the spatial and temporal changes in the groundwater flow system.