Coastal protection in the Wadden Sea is carried out in close cooperation with the other countries of the Wadden Sea region. The Advanced Dike, also called the Danish-German Dike, has consequently been built in cooperation with Germany and stretches across the border between Denmark and Germany. The Danish Coastal Authority cooperates with the German federal state of Schleswig-Holstein in order to prevent flooding, including storm surge warning.
Since 1998, the Danish Coastal Authority has also participated in the trilateral Wadden Sea working group on Coastal Protection and Sea Level Rise, in which coastal protection, nature conservation, and planning authorities from The Netherlands, Denmark, and Germany meet to prepare common guidelines for e.g. coastal protection in the Wadden Sea. In 2010-2013, the Danish Coastal Authority held the working group presidency.
Apart from handling the supervisory control of the Wadden Sea dikes, the Danish Coastal Authority handles the technical supervisory control of the dikes on the islands of Lolland and Falster.