The River Elbe in Germany - present state, conflicting goals, and perspectives of rehabilitation.
Scholten, M.; Anlauf, A.; Büchele, B.; Faulhaber, P.; Henle, K.; Kofalk, S.; Leyer, I.; Meyerhoff, J.; Purps, J.; Rast, G.; Scholz, M.
Based on an overview of the present state of the Middle Elbe River and existing management objectives concerning nature protection, navigation, and flood control, we describe conflicting goals. Regarding the course and structure of the river channel and floodplain, we will propose strategies and measures for integrated river management. We will focus on several scenarios of dyke relocation, which have been studied from a hydrological, ecological, and socioeconomic point of view. The retention effect of dyke relocation depends not only on the spatial situation (e. g., river section, area size), but also on the type of measure (controlled retention in storage polders or dyke relocation). Socioeconomic studies have shown a willingness by society to pay for dyke relocation amounting to about 108 million €a-1. The economic value of floodplain rehabilitation due to nutrient removal is assessed at 7 million € annually. Benefit-cost analyses were performed for several scenarios of dyke relocation and indicated a positive benefit-cost ratio even for the scenario with the highest costs. Finally, we report on experiences concerning administrative aspects of implementation of measures and discuss future perspectives of rehabilitation for the Middle Elbe River.