Public water supplies traditionally have been drawn from local surface or groundwater sources, and treated and distributed by localized water supply utilities (e.g., owned and operated as part of the local municipal government, local developer, homeowners association). Decades of population and economic growth, emerging regulatory demands, and other pressures have led many water professionals to note that regional approaches might provide opportunities where utilities might pool their efforts with neighboring systems to develop more reliable water supplies, facilitate compliance, or gain appreciable efficiencies. The purpose of this report was to examine the ways in which regional solutions may provide viable and advantageous approaches to addressing several of the challenges facing the water supply community. The researchers planned to provide a discussion of what regional solutions means, identify some of the key challenges facing water suppliers that regional approaches may help address, and describe how regional approaches may help utilities meet their sustainability objectives. There are many different ways in which regional approaches might be developed and implemented. This research used literature reviews, professional experiences, and case studies to develop a report that focuses on (1) describing the various options available for regional solutions, (2) providing information so that water agencies and other interested parties can better understand the pros and cons of the various alternatives available for their consideration, and (3) offering tools and lessons learned so that interested parties can chart a pathway to regional agreements, if they are deemed suitable.