Water characterises the cityscape and the urban ecosystem in many different ways. It is not only an essential resource, but also functions as a habitat - a co-habitat - in which humans and nature closely interact. In light of the global challenges of climate change and the urgent need for an ecological transition, the sustainable use of water in urban areas is of central importance. In Oldenburg, a city with diverse watercourses and wetlands, there are particular opportunities to develop forward-looking solutions through innovative approaches. Urban water systems face complex challenges: Increasing extreme weather events and changing precipitation patterns call for a redesign of urban infrastructure. The integration of co-habitat concepts requires a harmonious combination of ecological and structural elements in order to meet the needs of the population and nature at the same time. In addition, the ecological turnaround must also become visible in water management - for example through the use of phytoremediation to sustainably regenerate polluted water and soil. With the design studios, we want to develop an integrative, systemic and creative contribution to the urban use of water for Oldenburg that combines cohabitats, climate adaptation and ecological change. Through the design, the students will develop strategies that not only ensure the protection and sustainable use of water resources, but also create new, liveable urban spaces. The role of water as a driver of urban transformation and as a connecting element between the city and nature will take centre stage. The project will begin with a detailed analysis of Oldenburg‘s existing hydrological and ecological structures using GIS, mapping and on-site investigations. Building on this, scenarios will be developed using visualisations and physical models to illustrate the effects of climate adaptation measures and ecological interventions. Workshops and mixed working groups promote exchange between students. By comparing international best practice examples, a broad methodological framework is also created that integrates innovative solutions and sustainable approaches.