Water-demand management: Assessing impacts of climate and other changes on water usage in Central Arizona

Planning for sustainable water management in the arid region of the southwestern USA is challenging mostly due to only partial understanding of factors converging around water supply and demand. Some of the factors that prompt concern about the adequacy of water resources are: (a) a growing urban population seeking a range of services, including the need to preserve and enhance aquatic ecosystems; (b) dwindling water storage due to multi-year drought conditions; and (c) the prospect of human-induced climate changes and its consequences in the hydrologic system of the region. This study analyzes the potential for water saving in the Phoenix Active Management Area (AMA) of Central Arizona, which includes the city of Phoenix, one of the fastest growing metropolitan areas in the country. Based on an extensive literature review and secondary data analysis, this paper investigates multiple factors that place increasing strain on current water resources, and attempts to extend this analysis to 2025. Outdoor water use within the residential landscape is the most important factor that strains water resources in Phoenix AMA. Any gain in efficiency through agricultural water demand management would not only improve the availability of water for other uses in the AMA, but would facilitate adaptation of the agricultural system to climate and other ongoing changes.