In this research project, we engage with the misconception that all people in the United States enjoy water security by examining the case of people experiencing homelessness in the city of Phoenix, Arizona, in the southwestern United States. People who experience homelessness are disproportionately at risk of dehydration and heat-related illness as they spend significantly more time outdoors, and many have limited access to an adequate quantity of acceptable quality water. Our data were collected by using archival data, participant observation, surveys with people experiencing homelessness, focal follows with water distributors that serve homeless populations, phone and internet surveys with social service providers, and expert interviews with 14 diverse service providers. In this analysis, we focus on people living in three situations: (1) shelters, (2) encampments, and (3) with no roof. For those in the shelter category, the major problem is exposure to extreme heat and the financial barriers to coping with it. For those in encampments, the major problem is increasing physical and social isolation as a product of encampment raiding. For those with no roof, the major problem is inconsistent and uncertain access to water fountains and water trucks. We find that the sources of water vary across the economic sectors of the population and water sources become more unconventional the more socially marginalized a group is. Bottled water is a common source of water that plays a role as both a driver for and an inhibitor of water access. Individuals do not always have the means to purchase bottled water, yet it is also commonly shared throughout the community. We find that although the barriers to water acquisition vary, major coping strategies revolve around sharing. Finally, we find that there are a number of health impacts associated with water insecuritycoupled with extreme heatthat may lead to a cycle of homelessness or water insecurity.