In 2001, ADWR undertook a review of the Upper San Pedro Basin to determine if it met the statutory requirements for designation as an AMA. This report reviews the water supply and demand of the USP Basin in the context of the statutory criteria and includes a discussion of whether any of the criteria have been met. Previously, ADWR conducted a study of the USP Basin and issued a report in 1988 in which ADWR determined that the Basin did not meet the statutory criteria for AMA designation. ADWR indicated in the report that it would reassess conditions in the Basin in ten to fifteen years. The study described in this report is an evaluation of whether the conditions of the USP Basin satisfy the statutory criteria. This report contains a description of the current and projected water resources and water demand in the Basin, incorporating new information since the previous review. The report examines historic water use trends, evaluates the groundwater resources of the Basin, and projects impacts of future water use on Basin groundwater supplies. The report includes an evaluation of the incidence of subsidence or fissuring, and of the potential for groundwater quality degradation due to groundwater use. The report further describes and evaluates the impact that AMA practices would have on water use, and includes a summary of findings, the director’s determination of whether the Basin should be designated and recommendations.

Both the effect of climate change on our future water supply and the size of the population that will need to share in that supply are uncertainties that water planners must consider when making decisions regarding our future. We have options, but we have to be sure that we use water efficiently to meet our urban, agricultural, and environmental needs. This Policy Points offers a clear, succinct overview of the status of Arizona’s water supply and what the current drought really means for water availability.

As a result of high growth rates, physically and legally limited water supplies, drought, economic constraints, and relatively little comprehensive water resource planning and management, water supplies are stressed in some parts of Arizona. The Arizona Department of Water Resources has collected and synthesized currently available water-related information for the State of Arizona into a “water atlas,” organized by planning area.

The model was developed as a tool to better understand the complex and interdependent stream-aquifer system, and to provide guidance for the management of regional water resources. Water management topics relevant to the Santa Cruz AMA include bi-national water issues and the reliability of water supplies. This model was primarily calibrated over the recent effluent-dominated groundwater flow regime (1997-2002) because of the availability of high quality head, flow and pumping data. Thus, some model boundary conditions calibrated over recent periods may not necessarily be representative of pre-effluent conditions.