The provision of freshwater, particularly in urbanizing arid regions facing increased variability in precipitation patterns due to climate change, is one of the greatest challenges. Desalination--the conversion of seawater or brackish water to potable water--offers a potentially "limitless" supply of this vital resource. The preference for desalination, as an innovative, supply-side water augmentation option is gaining traction worldwide, including in northwestern Mexico. In arid regions, where water is a limiting factor to increased production and growth and nearly every drop of water is contested, a new technology that augments water supplies is likely to engender vast social, economic, institutional, and environmental transformations. Through an in-depth study of water management in the context of global climate change in northwestern Mexico, this dissertation examines the factors that lead to the adoption of desalination technology and assesses how the technology affects the communities where it is implemented. In seeking to understand the (potential) transformations and complex imbrications of this technology within the socioecological system in which it operates, four themes have emerged, including: 1) The best path towards improved water management is through investments in both infrastructure and institutions (i.e., governance); 2) Despite the real and urgent need to address the negative impacts of climate change on water resources, desalination should be considered as a "last resort"; 3) While desalination can increase water security at certain scales, it also introduces new vulnerabilities; and 4) While discursively, Mexico's water policy embraces principles of contemporary environmental governance (i.e., decentralization, public participation, and sustainability), these principles have yet to be fully implemented in practice. Policy recommendations include integrating land use and water planning, improving monitoring and regulation of groundwater extraction, increasing capacity building within water and planning agencies, and pre-conditioning desalination (or other supply-side water infrastructure projects) upon the successful implementation of a range of water conservation and system efficiency measures. Without such measures, increased water availability is likely to encourage additional growth, rather than resource conservation. Specific findings and contributions of this dissertation to the field of human-environment geography are discussed at the end of chapter two and in the appended articles.