Abstract: Developing robust systems for monitoring and evaluating water quality is crucial for assessing ecosystem
integrity and the impacts of human activities on nature. It also enables the assessment of water management
effectiveness, governance systems, and the design and evaluation of public policies. However, designing such monitoring programs is complex due to multiple constraints like eco-hydrological knowledge, economic resources, human capital availability, and governance dynamics. This study combines quantitative and qualitative analyses (virtual watershed methodologies, empirical modeling, and theoretical frameworks of water governance) to evaluate the robustness of water quality monitoring systems and identify strengthening alternatives (including institutional design and public policy). The inter and transdisciplinary strategy is tested in the evaluation of eutrophication processes in Uruguay. Major spatial patterns of water quality at a national scale were identified, highlighting the influence of land use, soil types, point sources of pollution, and livestock on nitrogen and phosphorus concentrations. Current monitoring efforts and spatial coverage fall short of adequately addressing water management needs, especially in Uruguay?s socio-economic context. Based on the weaknesses identified, an increase in the number of stations (and their spatial distribution) is proposed to have a better representation of biogeophysical and socio-economic conditions diversity. The challenge involves an important transformation (i.e. establishing a network system of public institutional nodes at national and regional levels) due to the country?s centralism, fragmented water governance system, and scarce economic assets.