Jörg Oehlmann will introduce the NiddaMan project as a local example of a transdisciplinary research project that developed and implemented a sustainable water resources management scheme along the river Nidda. Therein, citizens, administrative bodies as well as stakeholders from policy and science were engaged. Jörg Oehlmann will specifically reflect upon the scientific challenges in collaborating with non-scientific partners against the background of both interdisciplinary and essential disciplinary research work.