The EcoWater project developed a method for using eco-efficiency indicators to compare various improvement options with the baseline situation at the meso level, i.e. in a systemic approach. The meso-level focus analysed interactions among heterogeneous actors in water-use systems, both in the current situation and for the implementation of potential eco-innovations. The method was applied to eight case studies spanning three water use sectors (agricultural, urban and industrial). Each case made methodological judgements about numerous aspects of eco-efficiency assessments. Through such assessments, each case study facilitated multistakeholder discussions on improvement options, on factors influencing their adoption and on policy implications. This report compares those methods, judgements and their results across the case studies. As these comparisons reveal, improvement options are case-specific, e.g. dependent on the context, the environmentally weakest stage, the potential forsystem improvement and data availability. The general method was adapted to each case, especially so that the meso-level boundary and indicators encompass potentialeffects of the eco-innovations being evaluated. In this sense the step-wise method is iterative, sometimes reconsidering previous steps. The meso-level analysis adds information about effects beyond a micro-level focus on an organisation’s internal processes, sometimes reducing or complicating the apparent benefits at that level. In each case study, few options would be ‘win-win’ by improving all environmental indicators, increasing total value added (TVA) and financially benefiting all valuechain actors. Selecting the most eco-efficient options entails tensions and trade-offs among various objectives, thus complicating eco-innovation as a win-win strategy. The potential to optimise meso-level eco-efficiency, alongside various trade-offs, highlights the value of sharing stakeholders’ different understandings through mesolevel discussion, in ways appropriate to each specific context. As shown by comparisons among diverse cases, the general method was robustly applied – to assess options for eco-efficiency improvements, to evaluate their relative meso-level benefits, and to facilitate multi-stakeholder discussion on optimising the system. So the method has wider relevance to any meso-level water-service system. The report is structured as follows: Introduction to the methodology (section 1), results of the cross-case comparison with overall conclusions (section 2), in turn referring to results of each case study (sections 3-10), and documentary references. This report is only available in English.