Implications of spatially neutral groundwater management: Water use and sustainability in the Tucson basin

Arizona has developed strong regulatory mechanisms to ensure long-term sustainable water use, and to integrate land and water use planning for the most populated areas (Jacobs, 2009). The sustainability objective in Arizona’s water policy is based on the concept of “safe yield”; i.e., that the extraction of groundwater on a basin-wide and long-term basis is no more than is naturally and artificially recharged. This concept has been criticized by hydrologists, because it can be interpreted as implying that by achieving a balance between recharge and pumping there will be no detrimental impact on the aquifers and their dependent systems (Zhou, 2009). As a sustainability objective, the concept of safe yield may be considered as rather reductionist because it refers exclusively to the flows in and out of an aquifer, without taking into account other hydrogeological, socioeconomic and ecological criteria. Further, although limited, safeyield as a management goal is nevertheless challenging to both implement and evaluate.