The legal norms governing the distribution of water are integral to how access to water is determined. This paper analyses the idea that water should be used in the interest of the public from a legal point of view. Taking Swiss and South African law as examples it examines what the notion of ‘public interest’ actually means. A close look at the notion of ‘water distribution in the public interest’ reveals important insights: water distribution in the public interest balances a variety of different economic, ecological and social interests. In this process the human right to water is attributed the role as protective shield. Hence its effective implementation is crucial in order to safeguard water for basic human needs. After analysing how Swiss and South African water regimes are currently structured and the role of the public interest clause therein, the paper examines whether the human right to water as conceived in Swiss, South African and international law effectively ensures protection of domestic water users. The paper concludes that this is the case under some, but not all circumstances. Especially the interests of those users whose access to water is not yet sufficient do not always receive adequate legal protection by the respective legal orders. The paper concludes by stressing the necessity to evolve the concept of the human right to water to reach comprehensive protection of basic human needs. Consciousness of the social risks associated with using the human right to water as general placeholder for basic human needs despite its shortcomings will hopefully encourage efforts to establish substantive legal protection.