Increasingly, attention in regional, national, and international water governance arenas has focused on high-altitude wetlands. However, existing local water management practices in these wetlands are often overlooked. This article looks at the irrigation activities of alpaca herders in the community of Ccarhuancho in the Central Andes of Peru. For more than two centuries, they have been constructing small-scale irrigation canals to maintain and expand the local wetlands, called bofedales. The seminomadic character of alpaca herders complicates irrigated wetland activities, such as operation and maintenance. Climate change and human and animal population pressure have increased not only the importance of these irrigation systems but also of local conflicts and communal decision making. Local irrigation activities in Ccarhuancho go unnoticed in broader water governance arenas because of its remoteness, limits to what popular new analytical tools can measure, a general undervaluation of wetlands, and a tendency of the canals to merge over time with the surrounding bofedales, making them less visible. Nevertheless, these man-made systems account for 40% of the wetlands in the study area and risk being seriously degraded or destroyed without local water management. With climatic changes affecting existing natural wetlands, the local herders were the first to recognize and respond to these changes and to defend the wetlands against degradation. Their efforts are, however, largely overlooked, even though such local water governance practices are crucial for the success of regional and national water governance in the Andes and other mountain areas. (Note: The title of this paper is an adaptation of Netting's [1974] paper “The system nobody knows” about small-scale irrigation in the Swiss Alps.)