In 1585 , the island was connected with the mainland through the building of a dam . Subsequent deposits of sediment by the sea created new land , which was further secured through dikes . Storm floods continued to take their toll as documented in the St. Clemens church with a tabloid commemorating the Burchardi flood of 1634 flood , which killed 168 people and destroyed 102 homes in Büsum . During the devastating Christmas flood of 1717 , the village Werven near Büsum sank completely . The last great flood happened during February 1825 . Since then , the improved dikes have been able to protect the town from storm tides
Burchardi flood
Burchardi flood
Büsum