This paper examines the rise of various water narratives related to climate change in the Andes and Himalayas during the last several decades. It analyzes the great divide among: first, the dominant discursive framing of climate change impacts on water supplies below melting glaciers; second, the changing scientific projections about hydrology in glaciated watersheds; and, third, the actual use of water over time by stakeholders in these watersheds. Discourse about the effects of climate change on water supplies in glaciated watersheds has been similar in both the Andes and Himalayas. It offers dire warnings of rapidly declining water resources in both regions. As the story goes, more than a billion people will lose water as glaciers shrink. But the science on the Andes and Himalayas has gone in different directions. In the Himalayas, climate-glacier-water research has increasingly become more cautious over the last decade or two. The most recent studies question the impacts that climate-triggered glacier shrinkage will generate downstream and suggest the earlier alarm has been significantly exaggerated. In the Andes, however, the same public discourse about water decline has existed. Yet scientific studies increasingly point to more severe (not less) climate/glacier impacts on downstream water supplies. At the same time, and ironically, research on actual water users in Andean watersheds shows a marked increase of water use despite decreasing glacier-fed water sources over the last half century. Thus, other political, social, economic, and environmental factors obviously influence water management. This paper explores this fascinating interplay of public discourse (as expressed in the media and by government officials), the natural sciences (presented through hydrologic models), and actual water used by stakeholders, particularly in the Peruvian Andes. In both the Andes and Himalayas, scientists have failed to retain control of the dominant discursive construction of climate-water narratives. What's more, the scientific models of water under climate change do not align well with actual historical water use practices, thereby demonstrating shortcomings of climatic-hydrologic models and indicating a need for grounded historical research to complement modeled projections.