August 26, 2026
Photo Credit: Tom Nelson
PRESS RELEASE
Contact:
John Dougherty, Save the Scenic Santa Ritas, (520) 261-5014, jdougherty@scenicsantaritas.org
Tucson— Pima County is warning Hudbay Minerals’ plans to develop the massive Rosemont pit on the eastern slope of Santa Rita Mountains as part of its proposed Copper World project will “deplete the aquifer in perpetuity” while “threatening springs and streams” down gradient from the mine.
“All these impacts are expected to reduce the groundwater available to sustain Cienega Creek, Empire Gulch, Davidson Canyon and other groundwater dependent ecosystems,” Pima County Administrator Jan Lesher states in an Aug. 24 memo to the Board of Supervisors.
“Protecting these irreplaceable resources has been the focus of decades of conservation investments by Pima County, the State of Arizona, (federal) Bureau of Land Management and numerous other partners,” Lesher writes.
The report states that Hudbay has also encouraged state regulators to remove water quality protections from Davidson Canyon and narrow protections for Arizona’s most pristine streams classified as Outstanding Arizona Waters that are supposed to be protected from any degradation.
“Pima County’s latest report clearly shows the environmental devastation that Toronto-based Hudbay intends to inflict on one of the most important watersheds in Southern Arizona,” says Save the Scenic Santa Ritas Executive Director John Dougherty. “It’s gross negligence for the state to continue to facilitate development of Copper World.”
Copper World will drain at least 3 billion gallons of groundwater a year for at least 44 years from the Santa Cruz River valley that is already suffering ground subsidence. The mine will also destroy renewable surface water supplies as Arizona is in the grip of an historic drought.
“Arizona must shake off its bondage to the copper industry and begin truly focusing on preserving Arizona’s precarious groundwater and renewable surface water supplies that are the foundation of the state’s economy,” Dougherty says. “It’s the height of hypocrisy for state leaders to decry deep cutbacks to Arizona’s share of the drying Colorado River while greenlighting water wasting projects like Copper World.”
Lesher’s memo includes a 21-page report written by Tucson hydrologist Julia Fonseca that provides a stark assessment of the threats to surface and groundwater supplies from the Rosemont pit. Fonseca states that Hudbay intends to immediately begin dewatering the aquifer on the east side of the mountain.
“Much of the dewatering will occur during the first two years to reduce pore pressures in the formation prior to excavation,” she writes.
Hudbay does not plan to back fill the 467-acre pit, which will create an “hydraulic sink” that will reverse the flow of groundwater that now flows downgradient to recharge rare Sonoran Desert streams including Cienega Creek that is the heart of the BLM managed, 45,000-acre Las Cienegas National Conservation Area. Instead, groundwater will be drawn into the Rosemont pit where it will evaporate forever.
Fonseca also warns that Hudbay intends to discharge some of the groundwater pumped to dewater the mine site, which is likely to be “rich in metals”, into streambeds that Hudbay has not yet identified.
Hudbay intends to construct the Copper World project on private lands. The mining complex will include several open pit mines on the west side of the Santa Ritas, one across the top of the mountain in addition to the Rosemont pit, which would be by far the largest at more than a mile wide and a half-mile deep.
Construction on private lands allows Hudbay to avoid complying with federal environmental laws and significant mitigation requirements. “Hudbay currently offers no mitigation for the loss of wetlands or associated plants and animals,” Fonseca states.
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