This is an activity of the Working Group "Transdisciplinarity" of IAHS' scientific decade on hydrology and society "Panta Rhei".

Involvement of stakeholders in water management is increasingly recognised as essential. Guidelines and regulations such as the EU Water Framework Directive and the US Clean Water Act encourage collaboration and participation. In response, researchers and water managers are developing and applying methods to collaborate with stakeholders. In this session, we will explore the diverse array of concepts, approaches and evaluation tools being utilised by hydrology and water management researchers in this rapidly growing field. The overarching aim of the session is to exchange methods and findings. Themes covered by this session include:

• Modelling with stakeholders: from perceptual to procedural models; co-learning and co-management.
• Engaging stakeholders: incorporating stakeholder knowledge with hydrological knowledge to parameterise, drive and test models; scenario development; interpretation of model results.
• Decision-aiding processes and decision support tools.
• Eliciting and weighting stakeholder knowledge, modelling of uncertainty and addressing stakeholder concerns.
• Existing and emerging challenges and benefits from stakeholder involvement in hydrological research.
• Critical reflection, evaluating participation and measuring “success”.
• Social learning and emerging outcomes from collaborative research in water management.

This session will consist of a poster discussion session where all authors will have the opportunity to deliver a short summary presentation of their work, which will be followed by extensive discussion. Authors are advised that, instead of a small number of 15 minute talks, we aim for maximum discussion and exchange through a series of mini-talks plus posters by all presenters.