As the Panta Rhei initiative enters its 4th biennium we need to remind ourselves that a scientific decade on change in hydrology and society requires the perspectives of those disciplines that have traditionally been concerned with society, the social and policy sciences, as well as of society itself. While interdisciplinary conversations have been happening to some extent, transdisciplinary endeavours remain largely undocumented. The aim of this meeting is to discuss the next steps of the Panta Rhei Working Group Transdisciplinarity.