Regulation of nitrogen (N) loss from the agri-environment is a global challenge with dire consequences for food production and environmental management. This is also the case in Denmark where regulation largely relies on general measures for reducing N inputs. These measures have significantly reduced nitrogen emissions, but further reduction is needed to achieve sustainable low levels of N transport to freshwater and marine ecosystems in compliance with standards set by the EU Water Framework Directive. As an alternative to general regulation, we tested a watershedbased, collaborative planning approach, engaging stakeholders in solution identification. Six watersheds with substantial agricultural production were used as test areas. A collaborative planning process of two stakeholder workshops embedded within a scenario formulation process was executed. Stakeholder inputs about possible, desirable and sustainable futures were used to formulate scenarios, for which N reduction effects were calculated. Upon conclusion of this process, results were assessed using a structured evaluation method. Results indicate that the process we tested was successful in terms of (1) engaging relevant stakeholders, (2) providing relevant data, (3) achieving processual flexibility, (4) including local knowledge and (5) facilitating a creative and explorative process. On this basis, suggestions for improving collaborative planning processes are provided.