The debate on water emerged strongly at the international level, due to the worrisome phenomenon of water scarcity. Notwithstanding the obvious importance of water for existence on Earth, the right to water has at this moment an "ambiguous status within international human rights law". A treaty on the human right to water has not yet been adopted, hence this right has been derived from other rights already recognized at the international level. However, following the developments in recent years, the recognition of the right to water as a human right has increased thanks to the work by the UN Special Rapporteur on the human right to safe drinking water and sanitation. This article focuses on one question : should it be possible to determine that the right to water as an independent right, thus not derived from other rights, is a customary international norm ? The article begins with an extensive background on the development of the right to water in international and regional legal instruments before analyzing practice of States and opinio juris, the two fundamental elements of an international custom. The research demonstrates that, as far as the core content of the human right to water is concerned, it seems possible to say that a customary norm recognizing a "self-standing or independent right" has emerged.