The Lesotho Highlands Water Project (LHWP) is a multi-billion dollar effort to transfer water from the mountains of Lesotho to Johannesburg, South Africa. Faced with few other economic opportunities, the Lesotho government has placed water export at the center of its development strategy. State officials suggest that "white gold" can free Lesotho from dependence upon other nation-states, although many people in Lesotho suggest that revenues generated from the LHWP benefit an urban elite and not ordinary people. The opportunity to exploit this economic potential has brought water under new kinds of national scrutiny, calling into question who owns it, and what kinds of properties and capabilities it has. One particularly important arena of scrutiny is that of soil conservation efforts, where my ethnographic study is centered. Acute soil erosion threatens to reduce the capacity of Lesotho's reservoirs and compromise project infrastructure, leading the LHWP to implement erosion control programs collectively known as Integrated Catchment Management (ICM). ICM places the blame for soil erosion mostly on common land tenure, proposing to shift land management authority from chiefs to exclusive "grazing associations" controlled by commoners and state officials. Rates and causes of soil erosion are notoriously difficult to measure, however, and ultimately hinge on ideas about how water interacts with soil, and how these interactions are shaped by the practices of herders. This dissertation project investigates these empirically informed debates about water's behaviors and capabilities, and what new forms of association and resistance are emerging from such debates. Through twelve months of ethnographic fieldwork with ICM fieldworkers and ordinary people in the Lesotho highlands where ICM is being implemented, I ask: What are the socio-political implications of changing ideas and practices surrounding water in Lesotho?