Only 1% of the surface water in the Netherlands has been classified as ‘good’, making it the EU member state with the worst quality of surface water (Didde, 2022). Polluted rivers cause problems such as worsened human health, reduced biodiversity, and poor soil fertility. To comply with the Water Framework Directive, there is an urgent need to transform water management in the Netherlands. This report adopts a research-by-design approach to address the issue of water pollution on a pilot project scale, specifically the river Eem in the Netherlands. The policies and interventions implemented in the river Eem area are categorised according to their transferability to different programming areas, namely urban, industry, or agriculture, creating a toolbox that can be used to upscale the same approach in various parts of the Eurodelta. The report answers the following research question: How can the transformation of the Eem Valley turn the river Eem into the healthiest river in Europe as a pilot for the Eurodelta? It catalyses rethinking pollution flows from human activities, industries, and agricultural practices. The goal is to develop sustainable practices for the land surrounding the river and create a synergy between improved soil and water quality. Finally, the report concludes with a toolbox of interventions and policies that contribute to improving river water quality. The toolbox forms the basis for implementing this small-scale approach on a larger scale