As part of its policy to combat climate change, the Grand Est Region voted, in plenary on 29 June 2023, on its "climate change adaptation" roadmap. One of the 45 actions listed is the establishment of a water observatory on a Grand Est scale. This observatory has several objectives: capitalise on existing data in a homogeneous manner relating to the quality and quantity of the water resource, uses and knowledge of the environment; make these data accessible in a synthetic and pedagogical manner; meet the needs of local stakeholders, by centralising all information in a single access point. It will also facilitate the integration of water-related issues into regional and local planning documents, and will make it possible to value these data through relevant indicators, while supporting the steering of public policies and regional action.