Watershed governance typically relies on more or less formal inter-organizational networks whose structure is likely to influence the success of cooperation. An emerging body of literature seeks to analyze the role of networks in natural resource management. This paper aims at contributing to these developments by developing a research frame to assess the effects of the structure of inter-organizational networks on the outcomes of watershed governance. We focus on a specific type of watershed partnership developed in France in the frame of European agri-environmental policy with the aim of limiting nonpoint source pollution from agricultural sources: the Local Agri-Environmental Schemes. The paper reviews how the different network structural properties may affect the success of collective action for natural resource management, on the basis of the literature using the tools of social network analysis. The case of the Local Agri-Environmental Schemes in the French context is presented as well as some first empirical evidence about the role of networks in the success of these schemes. Finally, the conceptual insights provided by the social network literature are used to formulate some assumptions to be tested in future work.