The future of the Rhine: stranded ships and no more salmon?

Climate studies show high likelihood of changing hydrological regimes in European rivers. Concerned authorities increasingly question the sustainability of current river management strategies. The aim of this paper is to apply the adaptation turning point (ATP) approach and demonstrates its potential for analysing turning points in river management strategies as a method to support authorities in decisions on adaptation to climate change. Two management strategies in the Rhine River basin were selected as case studies: (1) reintroduction of a sustainable population of Atlantic salmon and (2) inland shipping in relation to water depth variability. By applying the turning point approach, we search for answers to the following questions: when will these management strategies fail due to climate change impacts on the river's hydrology? What adaptation measures exist to delay or avoid failure? The identification of adaption turning points is not easy, due to large scenario and model uncertainties in transient future projections of low-flow discharges and water temperatures. But the case studies demonstrate that the ATP approach is salient from a decision-maker's perspective, because it addresses the timing of possible failure of current management strategies. Analysis of results allows policy makers to assess risks and the urgency for action and provides them with a time horizon for adaptation planning. It is also a valuable first step in the application of methods of formal appraisal of adaptation options when flexibility in planning is required.