Is the Hydrologic Cycle Sustainable? A Historical–Geographical Critique of a Modern Concept

The hydrologic cycle is treated in this article as an invention that represents and helps structure a particular understanding of water. Ideas about the circulation of water in what is now called the hydrosphere have been discussed for millennia, and quantitative proof of the basic water balance (between evaporation, precipitation, and streamflow) was established by the nineteenth century. However, "the hydrologic cycle" as a distinct entity and the diagrammatic form by which it is typically represented are much more recent products of hydrological discourse. This article describes the gestation of this entity in the English-speaking hydrological tradition and explains how and why it attained a specific form in the United States in the 1930s. This modern hydrologic cycle, it is argued, internalizes the historical and geographical circumstances in which it was formed; namely a northern temperate society in the throes of modern, state-led industrial development. These circumstances, however, no longer pertain to a majority of people, whose experience of water is different from that represented in the standard hydrologic cycle. To the extent that it structures an understanding of water that is increasingly at odds with social and hydrological experience, the modern hydrologic cycle can be considered unsustainable.