In its present emergent form, International Water Law (IWL) is concerned with enabling States to demonstrate an end result of equitable and reasonable sharing of transboundary waters, and thus does not directly address the cause of behaviour which may prevent this goal from being realised. In addition, this consent-based system is insufficiently developed to redress issues arising from the use of covert ideational power by one state to achieve control over water resources shared with other states. By offering a means to describe, analyse and demonstrate how the use of power by a State is a major determinant of its behaviour regarding sharing water resources, the approach of hydro-hegemony may help address such shortcomings, and thus be of some use to IWL. This paper presents a straightforward introduction to the area overlapped by International Water Law and the Framework of Hydro-Hegemony. We further explore how the Framework could make a direct and practical contribution to the knowledge of legal norms for state behaviour regarding the use of power and water sharing. The Framework of Hydro-hegemony shows that the covert use of power by a State can be used to perpetuate water sharing arrangements that can be inequitable and unreasonable, yet tolerated and even ‘stable’, in that they are not readily challenged. At present, hegemony and IWL coexist as parallel tracks, with the law being effectively blind to what is actually happening. We suggest that international water law must become aware of these covert hegemonic practices and incorporate them into the determination of compliant State practice if the principles of equitable and reasonable use are to be properly operationalised.