Book excerpt: The object of the research work is the analysis of the multilevel protection of the human right to water and the current degree of implementation that it has received in international, European, and national law, comparing the Italian and German contexts from the constitutional law perspective. Given the absence of an express recognition of the human right to water, another research question concerns the examination of the mechanisms of multilevel protection of human rights, assessing whether the relationships between the different levels of protection can contribute to the realisation of this fundamental human right. The research analyses the main sources of law and jurisprudence of each examined context, to understand the legal basis for the recognition of the human right to water, considering both the necessary protection of environmental aspects, as well as social and economic ones, fundamental for its full realisation. The analysis of normative and jurisprudential sources is supported by the examination of the most relevant doctrine.