Experience with integrated water quality management in the Wahnbach Watershed

This paper describes how integrated water quality management has been developed for Wahnbach reservoir and the experience which has been gained with this multi-barrier system. Different measures in the catchment area, where co-operation with farmers was most important, are combined with the operation of a phophorus elimination plant, in which the main tributary is treated, and with aeration and biomanipulation in the reservoir. All measures together have led to the present oligotrophic state and the excellent hygienic condition of the reservoir.