Water touches virtually all societal and environmental domains. The knowledge domain is largely multidisciplinary. New water information and knowledge can thus lead to more efficient use of environmental services and better handling of environmental problems, including those posed by climate and environmental change. The project SWITCH-ON explores and exploits the currently untapped potential of open environmental data to address water issues. Water information is of interest to many kinds of end-users, both within government and business as well as within civil society. SWITCH-ON will show the benefits achieved through the whole process chain. The project aims at re-purposing (re-using under different context) open data products into more water-dedicated and refined products. Those are considered to have high value and a broad impact on society.