The dataset of this paper originated from quantitative survey data and qualitative expert interviews with organizational actors relevant to the governance of ten Swiss wetlands from 2019 till 2021. Multi-level networks represent wetlands governance for each of the ten cases. Collaboration networks of actors form a first level of the multi-level networks. The collaboration network is connected to multiple other network levels that account for the social and ecological systems those actors are active in. 521 actors relevant to the management of the ten wetlands are included in the collaboration network; quantitative survey data exists for 71% of them. A unique feature of the collaboration network is that it differentiates between positive and negative forms of collaboration depending on actors' activity areas. Therefore, the data describes not only if actors collaborate but also how and where actors collaborate. Further additional two-mode networks (actor participation in forums and involvement in other regions outside the case area) are also elicited in the survey and connected to the collaboration network. The dataset also contains data on ecological system interdependencies in the form of conceptual maps derived from 34 expert interviews (2-4 experts per case).