This talk advances a decolonial critique of water governance and diplomacy by challenging the dominant security–peace narrative that frames water cooperation as a technical pathway to stability. Drawing on recent work on decolonising water diplomacy, it argues that this paradigm obscures deeper questions of justice by prioritising conflict management and geopolitical order over equity and lived realities. The talk proposes a shift from a security–peace framework to an equity–identity approach, where water is understood not only as a resource, but as embedded in social relations, histories, and cultural meanings. In doing so, it introduces hydro-decolonisation as a fourth paradigm in water politics—one that moves beyond cooperation and stability to interrogate the power structures and epistemologies that shape what counts as “peace” in the first place. Rather than adding justice as an additional layer, this perspective calls for rethinking the foundations of water diplomacy itself, opening space for plural knowledges, historical accountability, and more transformative approaches to transboundary water governance.