mirage in the VALLEY OF THE SUN, the

Environmental History, Jul 2008 by Hirt, Paul, Gustafson, Annie, Larson, Kelli L

On the surface, the GMA seemed visionary, unprecedented, a serious longoverdue effort to end the groundwater overdraft problem. In 1986, the Ford Foundation recognized Arizona's GMA as one of the ten most innovative programs in state and local government.51 For the three most populous areas of the state, the primary objective of the GMA was to attain "safe-yield" of groundwater by 2025, defined as "a long-term balance between the annual amount of groundwater withdrawn in an AMA and the annual amount of natural and artificial recharge in an AMA." The Act created the Arizona Department of Water Resources (ADWR) to implement its policy goals, including a new program of groundwater withdrawal rights; a system for registering groundwater wells and reporting usage; a mandatory conservation program that established specific water reduction goals for agricultural, municipal, and industrial users; and a requirement for developers to demonstrate a one-hundred-year assured water supply for new housing.52

This regulatory program focused on the rapidly growing urban areas of the state-Tucson, Phoenix, and Prescott-as well as the agricultural area of Pinal County between Tucson and Phoenix, regions in which groundwater overdraft was the most severe over which ADWR would have the most authority to enforce conservation programs. These areas were designated "Active Management Areas" (AMAs) under the new groundwater code. The AMAs included 80 percent of the state's population, 60 percent of the state's groundwater pumping, and 70 percent of the state's overdraft. The Phoenix AMA is the largest at 5,646 square miles.53

In order to establish a timeline to meet the goal of safe yield, the GMA mandated five consecutive water management planning periods spanning from 1980 to 2025. At the time of this writing, in 2007, the Phoenix AMA was near the end of its Third Management Plan period and drafting its fourth plan. In principle, each successive management plan would contain more rigorous conservation requirements. As water scholar Robert Glennon explained, "The GMA operates like a ratchet and moves only in one direction: controlling water use."54 In contrast, however, our analysis of the successive management plans for the Phoenix AMA reveals that the ratchet is slipping in the reverse direction.

The First Management Plan required modest but specific goals for the reduction of agricultural and municipal water use. For farmers, it established the long-term goal of "maximum feasible conservation," tied irrigation rights to cropping patterns of the previous five years, and prohibited agricultural expansion in the AMAs. ADWR defined maximum feasible conservation as 85 percent efficiency in crop irrigation; in other words, under best practices only 15 percent of irrigation water should be lost to evaporation or run-off. ADWR then set targets for gradually reducing the irrigation allotments until farmers reached 85 percent efficiency. If farmers did not use their allotments, they could bank those irrigation rights for later use.