Sarah Porter: Visualizing Well Development Near Arizona Rivers
A new tool from Arizona State University’s Kyl Center might help prevent declining surface water flows in the state
By Sarah Porter, director, Arizona State University’s Kyl Cetner for Water Policy, Morrison Institute
Arizona water managers have on old saw that goes, “If you want to know where the rivers are, look for the wells.”
As populations have swelled in some of the state’s rural areas, concerns have emerged that wells drilled near rivers and streams may be responsible for reduced surface flows.
The Threats from Wells to Surface Water Levels
A United States Geological Service study has even concluded that in the Sierra Vista Sub-watershed, in southeastern Arizona, “even if pumping were immediately reduced or stopped,” the cones of depression resulting from the area’s wells “would continue to propagate for decades or more. . . . Without significant mitigation measures, it is likely too late to prevent declining water levels from reaching the San Pedro River riparian area” (Gungle et al., 2017). Likewise, models have shown that well development in Central Arizona could deplete flows in the Verde River (Leake & Pool, 2010).
The potential for these wells to deprive surface water rights holders of their full water entitlements is at issue in Arizona’s Gila Watershed Adjudication, a complex court proceeding to determine all of the surface water rights in the Gila Watershed and its tributaries, including the Verde and the San Pedro Rivers, and it is possibly that many wells will be deemed to be illegally misappropriating water to which a more senior user is entitled. In the meantime, there is no check on additional well drilling in these areas.
A New Map of Arizona Well Development over Time
To help explain what’s happening in these places, ASU’s Kyl Center for Water Policy, part of Morrison Institute for Public Policy, worked with ASU’s Decision Theater to develop a data visualization tool, a map that shows well development over time in five of the state’s river basins: the Verde, the Salt, the Upper San Pedro, the Lower Gila and the Santa Cruz. Using the state’s publicly available well data, the map vividly illustrates the recent rapid development of wells concentrated near these rivers and their tributary streams.
For more information about wells, the Gila Adjudication and their implications for Arizona’s water resilience, read the Kyl Center’s report, The Price of Uncertainty.
Sarah Porter directs Arizona State University’s Kyl Center for Water Policy, Morrison Institute.
