Introduction: This article examines how the institutional arrangements governing the Bama irrigated plain (Burkina Faso), against a backdrop of climate variability, produce differentiated categories of water users, rank their access rights, and fuel conflicts of legitimacy. Methods: The study draws on a qualitative, socio-anthropological research design combining documentary research, direct observation and thirty-nine semi-structured interviews conducted in May 2026 with key actors in local water governance. Results: The findings show that the distinction between ‘on-scheme’ and ‘off-scheme’ farmers is a social and institutional con struction that structures power relations around the resource. Conflicts thus appear less as a direct consequence of climate vari ability than as struggles over the qualification and legitimation of water uses. According to participants’ accounts, these tensions are fuelled by unequal access, weak institutional arrangements (cooperatives, the Local Water Committee) and the deterioration of hydraulic infrastructure. Conclusion: Rehabilitating infrastructure is unlikely to ease these tensions durably unless it is accompanied by governance that recognises the different categories of users. The article calls for a concerted water-allocation framework that takes climate risk into account.