In the context of global environmental changes, water scarcity has become a challenge, especially for rapidly urbanizing regions. Water conservation—demand management—has therefore become an important tool for managing water resources. Since communication is at the core of water conservation strategies, we use Twitter data to trace the construction process of a widespread discourse at the global scale. We conduct a quantitative textual analysis of the Water-Use It Wisely Twitter timeline dedicated to promoting water conservation in Arizona. Based on the text of 3500 tweets and profile descriptions of 15,204 related Twitter accounts, our results show that Twitter is used to convey a standardized water conservation message that finds an audience worldwide, even though some countries block the use of Twitter or use other technical tools. This communication aspect on social media, where a network of water professionals and a community of water activists can interact, works as a cornerstone in the construction of an institutional consensus around this new paradigm of water management.