Decision Support for the Selection of Measures according to the Requirements of the EU Water Framework Directive

One major scientific challenge posed by the EU Water Framework Directive (WFD) is the design of a decision support process that meets the Directive’s requirement to achieve “good status” for all water bodies using a cost-effective combination of measures. This paper presents BASINFORM, a new decision methodology for selecting cost-effective management measures, developed in close co-operation with the water authorities and tested in the 5,154 km² mesoscale river Weisse Elster in central Germany. BASINFORM comprises (i) a procedure for framing the specific problems in the water bodies, including quantification of the need for action, (ii) modelling tools for quantifying the impacts of management measures, and (iii) a method for selecting cost-effective combinations of measures. One innovative feature of BASINFORM is that it structures the complex decision problems appropriately for practical use and provides an easy-to-use framework for integrating scientific and practical knowledge. A trial run applying BASINFORM to the Weisse Elster catchment revealed that good surface water status with respect to nutrient levels cannot be achieved if only the “standard” actions of current water management are taken to reduce point sources (sewage treatment) and diffuse agricultural sources. It also became clear that the nutrient-reduction measures available will generate considerable costs. The application of BASINFORM in this case study demonstrated its practical applicability in the WFD implementation process. Beyond the case study described here BASINFORM is currently being used for practical implementation of the WFD in the German Federal State of Thuringia.