The University of Amsterdam (UvA) and Surf Pill are launching a joint research project to investigate whether a floating surf installation with integrated water purification can improve water quality in Amsterdam's inner waterways. Once the permitting process has been completed, the first prototype will be built in Amsterdam-Noord. During the Paris 2024 Olympic Games, it became visible how vulnerable urban waters can be. Major investments were needed to make the Seine suitable for swimming, but after heavy rainfall, bacterial levels again rose to unsafe levels. The attention gave a boost to the Swimmable Cities movement, which by mid-2025 brought together over 150 organizations from more than 80 cities in 30 countries, all working to restore urban waterways. In early November, London also joined, alongside cities such as Paris, Budapest, and Rotterdam. Amsterdam faces similar challenges. In particular, shallow, stagnant areas behind bridges and near quaysides can show rapid...