This book provides an in-depth study of Lake Urmia in north-western Iran, a region that has mutated from a turquoise solitaire into a white desert. While hydrological and technical perspectives dominate existing research of this region, this book turns to the underexplored social, discursive, and ontological dimensions of the crisis. Building on its theoretical foundation, the book traces Iran's water history, from ancient irrigation to modern dam-building, showing how centuries of governance prepared the ground for Lake Urmia's decline. Drawing on 77 qualitative interviews, 115 scientific publications, and a wide corpus of policy documents, the book interrogates four central controversies: the disputed causes of desiccation, the impact of the causeway, the contested ecological water level, and competing restoration strategies. It also compares Lake Urmia with the Aral Sea, noting both the value and the limitations of this analogy, while demonstrating how Urmia's disappearance resonates beyond ecology by provoking a profound crisis of identity for local communities. Through the hydro-social cycle and Latourian concepts, the study employs controversy mapping to reveal how authority and knowledge shape problem framings and proposed solutions. Rather than closing the debate, it calls for a plural, context-sensitive approach that foregrounds diverse perspectives and contested futures of Lake Urmia.