The Danish Agwaplan project is a water environmental planning project trying to find new ways to change practice in terms of land use on farms. The project has its starting point in a dualistic learning theoretical perception that improving of farmers’ environmental knowledge will lead them to change their management practices. The project results show that the expected change in farming practices in many instances failed to happen, especially in a long‐term perspective. This study introduces the theory of communities of practice as an analytical framework to identify the sources of the problems in the Agwaplan project and demonstrates that to get from knowledge to an actual change in practice you need an integrative perception of learning and practice that incorporates knowledge and practice in a social context around the farm. The change depends on the opportunities the farmer has to create new identities. This paper suggests to base future water environmental planning projects on the actual social context. Such projects can improve their results by considering the farms involved as communities of practice and that these communities of practice including meaning negotiations as the generative unit for change.