Abstract: Knowledge on the practical support from data ecosystems to disaster risk reduction remains partial. More specifically, we misunderstand the drivers and challenges inherent to emergency data ecosystems development in cross-border regions. We also miss cases of data ecosystem building in those regions. This research addresses these gaps by abiding by the principles and guidelines of visioning, a prospective and collaborative research design. Based on qualitative interviewing and archive analysis of the case 2020 Roya Valley floods, this work provides a prospect of a segment of data ecosystem that involves an organizational field aiming at Disaster Risk Reduction (DRR) at the French-Italian border. Still in progress, this work provides a comprehensive narration of a fictious data ecosystem. The narration hints at the major benefits and challenges inherent to this potential data ecosystem. This work enriches our understanding of data ecosystems’ features and benefits to cooperation between organizations involved in emergencies at borders (such as governments, civil protection agencies, volunteer-based organizations). In future development it will propose an agenda to support practitioners in the development good practices related to data ecosystems.