Sea level rise due to climate change will dramatically increase the probability of flood hazards for the City of Hamburg in the next century. The pressure in any flood protected areas will be further increased due to the City's plan to foster the development of new urban areas by “The Jump over the River Elbe”, and by making use of the deep lying open space on Wilhelmsburg Island and the former harbor areas of HafenCity, Graasbrook and Reiher Stieg. Recent years have demonstrated that the City of Hamburg is also affected by pluvial and fluvial floods of small urban rivers.
The most extreme storm event in 2002 caused more than € 15 million damage and showed about 6,000 hot spots of high flood risk within the City of Hamburg. Climate adaptation and the political program of a “Growing City” will increase the pressure throughout the whole city area. Conventional flood defence strategies such as enhancing the transport capacity of the storm-water pipe network and encroachment of the small urban rivers through dikes are neither technically nor economically feasible.