Access to environmental information is a major momentum for public policies. In many ways, data publication is known as a key factor for topics appropriation by stakeholders, and can be used as an effective lever towards public opinions. Furthermore, collecting data and guaranteeing their public access are legal obligations for EU Member States since the early 2000’s. This study compares three institutional and technical processes: (i) river boat fishing monitoring and related quotas, (ii) commercial and personal water abstraction declaration facilities and (iii) the register of plant protection products sales. Two main axes are chosen to highlights differences in process and policy efficiency, as far as data are concerned: level of technical complexity and maturity of processes (for instance, acceptance by stakeholder). Main conclusions echo with others data policies reviews: technical feasibility doesn’t seem to be the main barrier in studied cases, whereas knowledge of purely functional and organizational trade aspects (established know-how and expertise) is a key element for success. Also, open data strategies should still prevail in public services, where departitioning data, informatics, scientific, organizational and legal task forces is a great concern. Beyond this coordination issues, because environmental phenomena don’t know frontiers nor boundaries, international frameworks and initiatives should prevail on local engineering, regardless of local data strategies, as far as national secrecies and policies are heeded.