Spatial Data Infrastructures (SDIs) are considered an essential driver of institutional spatial data diffusion. Due to the dual impact of system interoperability and changes in the legal framework, institutional spatial data are more and more accessible th rough the widespread deployment of SDI. This facilitates the discovery, access, exchange, and sharing of geographic information and services among stakeholders from different levels in the spatial data community. Standards are the key to developing interoperable platforms on the web. The promotion for access to geographic information aims to encourage its publication as open data, i.e. freely available to everyone to use and republish as they wish, without restrictions due to copyright, patents, or other control mechanisms. Spatial data infrastructures are often reduced to simple websites or webplatfoms for consulting spatial data on a region via a geoportal and downloading them from a geocatalogue, whereas, in fact, they are sociotechnical tools, revealing some of the major changes affecting the present system for producing and circulating spatial information. They are mainly run by government authorities, but deal with society as a whole, making it possible to observe the reorganisation of power relationships around data sharing on the Internet. This situation raises several research questions, in terms of identifying the spatial data actually accessible via these platforms, the usage of these data and the related impact on governance and environmental management. Within this context, our research proposes to provide a comprehensive view of spatial data sharing, based on four dimensions data accessibility, interoperability of information systems, actor networking, and informational equality of territories. To explore these four dimensions, this paper is restricted to the study of the relationship between French institutional SDIs implemented at different organizational levels and the users interacting with them as part of their professional practices. Based on an online survey and on statistical, structural and thematic analyses of qualitative and quantitative data, the study gathers the various practices, needs and points of view of public users and producers of spatial data. Public bodies working for environmental management (government service, local authority, public institution...) are specially targeted. The analyses of responses provide three types of results: the profile of the users, the French SDIs they use, and their contribution to the environmental management in terms of data accessibility, stakeholder networks, interoperability of tools, and informational equality in different regions.