Making a vicious cycle virtuous: A research and policy agenda for advancing the water security of unregulated users in the Southwestern U.S.

In the United States, most residents receive water from centralized utilities regulated under the federal Safe Drinking Water Act. Yet, a sizable portion of U.S. residents satisfy their household water needs through decentralized means, including domestic wells, very small water systems, and hauled water. These federally unregulated water users are among the most vulnerable to the impacts of climate change, particularly in aridifying regions like the Southwest. They are, however, inconsistently monitored and regulated at the Tribal, federal, state, and local levels. Compared to regulated users, very few programs exist to assist this population in securing and maintaining safe, affordable drinking water access. This neglect creates a vicious cycle whereby their water security needs remain both poorly understood and inadequately addressed. We review available data sources, regulations, assistance programs, and published studies relevant to unregulated water users across the Southwestern U.S. to illustrate this injurious feedback loop. We then propose four key areas for intervention to transform this vicious cycle into a virtuous one. Drawing on new insights from the emerging literature on modular, adaptive, and decentralized (MAD) water infrastructure, we highlight opportunities for investment and innovation to support decentralized service alongside existing investments in centralized infrastructure, and the critical need to attend to justice in the design and implementation of such policies. This article is categorized under: Science of Water > Water and Environmental Change Human Water > Water Governance Human Water > Rights to Water