California’s arid San Joaquin Valley was once inundated by lakes and wetlands. Through settler colonial discourses of contamination, a network of canals and aqueducts drained these lakes and wetlands in the late nineteenth century. Now, the Valley’s air and water are contaminated by pesticides, nitrates, and hydrocarbons from oil extraction and large-scale agriculture. Building from archival research and participant observation with environmental justice activists, this paper bridges settler colonial and critical Indigenous studies, work on racial capitalism, and feminist science studies to investigate logics of contamination in the production of private property through hydraulic projects. California’s hydrologic history shows that ideas of contamination were contested alongside emergent ideas of the racialized body. Hydraulic infrastructure, then, was not only an economic project but functioned within a larger logic of contamination that further articulated racial formations and settler sovereignty claims. Yet chemical contamination can also induce futurities, intimacies, and collectivities in powerful ways, as environmental justice activists in the valley consistently highlight. I argue that a critical analytic of contamination can trace how racial categories are ecologically produced and reconfigured, not only through differential relationships to land, but through changes in the land itself.