This interdisciplinary volume examines how nine arid or semi-arid river basins with thriving irrigated agriculture are doing now and how they may change between now and mid-century. The rivers studied are the Colorado, Euphrates-Tigris, Jucar, Limari, Murray-Darling, Nile, Rio Grande, Sao Francisco, and Yellow. Engineered dams and distribution networks brought large benefits to farmers and cities, but now the water systems face multiple challenges, above all climate change, reservoir siltation, and decreased water flows. Unchecked, they will see reduced food production and endanger the economic livelihood of basin populations. The authors suggest how to respond to these challenges without loss of food production, drinking water, or environmental health. The analysis of the political, hydrological, and environmental conditions within each basin gives policymakers, engineers, and researchers interested in the water/sustainability nexus a better understanding of engineered rivers in arid lands.