River Basin Districts (RBDs) and/or their subunits are the main units for the management of river basins and have been delineated by Member States under Article 3 of the Water Framework Directive. The geographic area of some RBDs span more than one country (such as the Danube) and these are known as International RBDs. Others are contained completely within a country and are known as National RBDs. River basin districts are defined as the area of land and sea, made up of one or more neighbouring river basins together with their associated groundwaters and coastal waters, which is identified under Article 3(1) as the main unit for management of river basins. Coastal waters are defined as one nautical mile from the coastline and extending, where appropriate, up to the outer limit of transitional waters. Coastal waters are included in RBDs, but this is not consistenly reported by Member States. Transitional waters are defined as bodies of surface water in the vicinity of river mouths which are partly saline in character as a result of their proximity to coastal waters but which are substantially influenced by freshwater flows. For more information about European waters, please visit the WISE portal (http://water.europa.eu/).

River Basin Districts (RBDs) and/or their subunits are the main units for the management of river basins and have been delineated by Member States under Article 3 of the Water Framework Directive. The geographic area of some RBDs span more than one country (such as the Danube) and these are known as International RBDs. Others are contained completely within a country and are known as National RBDs. River basin districts are defined as the area of land and sea, made up of one or more neighbouring river basins together with their associated groundwaters and coastal waters, which is identified under Article 3(1) as the main unit for management of river basins. Coastal waters are defined as one nautical mile from the coastline and extending, where appropriate, up to the outer limit of transitional waters. Coastal waters are included in RBDs, but this is not consistenly reported by Member States. Transitional waters are defined as bodies of surface water in the vicinity of river mouths which are partly saline in character as a result of their proximity to coastal waters but which are substantially influenced by freshwater flows. For more information about European waters, please visit the WISE portal (http://water.europa.eu/).