Hydrogeologic Investigations of Rural Watersheds in Parts of Northern and Southeastern Arizona

Water managers in rural Arizona are under increasing pressure to provide sustainable supplies of water despite rapid population growth and demands for environmental protection. There are concerns among water planners, local citizens, and environmental groups about the sufficiency of ground-water supplies and the potential undesirable consequences  that expanding ground-water development may have.  In response, the Arizona Department of Water Resources Department is collaborating with the U.S. Geological Survey to conduct hydrogeologic investigations to improve the understanding of the available water supply in several rural areas of Arizona—the northwestern Arizona basins of Detrital, Sacramento, and Hualapai,  the southeastern Arizona middle San Pedro Basin, which includes the Benson Subwatershed and a portion of the Lower San Pedro Basin, and the southeastern Arizona Willcox and Douglas Basins. 
These rural watershed studies are being conducted using a common set of objectives, which are: (1) assess the existing data-collection networks, and examine the current state of knowledge of the ground-water flow system; (2) improve the understanding of the hydrogeologic framework; (3) improve the knowledge of the ground-water flow system, quantify the water budget including total water in storage, and evaluate historical changes; (4) develop predictive numerical ground-water flow models; (4) evaluate ground-water quality in selected areas; (5) establish a hydrologic monitoring network for on-going assessments and changes in aquifer conditions, and; (6) inform the hydrologic community and local residents about hydrologic conditions. These studies employ a common approach to build hydrogeologic frameworks using data collected to characterize flows and water levels, geophysics, and geochemistry.  The frameworks will next be used to construct ground-water flow models appropriate for each basin.