A n object - oriented Bayesian network is used to link a cascade of sub - models across drivers, pressures, states, impacts and societal responses to lake eutrophication. Systems dynamic, empirical and expert judgement models are integrated in the network to assess trade - offs in ecological, social and economic values from improving lake ecological condition achieved using n utrient abatement measures in a catchment in South - Eastern Norway . ‘ Integrated valuation’ of ecosystem services is defined as an approach and then tested against this network model . The e xtent to which the integrated valuation network provides decision - support for implementation of t he EU Water Framework Directive is evaluated. The integrated valuation network makes it possible to assess the combined uncertainty management predictions due to natural temporal variability, spatial heterogeneity, monitoring data resolution, sub - model prediction error and information loss at model interfaces. We find the integrated systems model is a useful tool for assessing where additional data would provi de most information value across the system , but also that joint uncertainty places its application to EU policy on eutrophication control in the realm of ‘eutropia’.