Due to rapid economic development and population growth, China is facing severe water problems that include sea-level rise and increasing salinization, floods, water pollution, water shortage, soil erosion and ecosystem deterioration, as well as biodiversity loss. In recent decades, China is progressively more concerned with its water issues that are now at the center of social and political attention. Having to overcome similar challenges, Germany has taken a leading role in the field of water sciences and technology. In particular, China can benefit from the lessons learnt in Germany concerning the rehabilitation of water resources in areas heavily affected by chemical industry and mining after the reunification in 1989. German-Chinese cooperation in water sciences started over 25 years ago and dealt with increasing challenges in the 21st century. Following the open space workshop during the Water Research Horizon Conference in Berlin 2014, this article provides a view of some of the challenges and potential opportunities of German-Chinese cooperation in water science and technology.