Denial would paralyze construction of the project that would destroy a crucial watershed and deplete groundwater beneath Sahuarita/Green Valley
Sept. 9, 2026
Tucson—Pima County has requested the Arizona Department of Water Resources to not renew Toronto-based Hudbay Minerals’ groundwater withdrawal permit for its proposed Copper World mine when it expires in January 2028.
The current permit issued in 2008 allows Copper World to pump up to 6,000-acre-feet (2 billion gallons) of groundwater a year. Copper World has stated in a technical report that the planned mine could require between 9,400 and 14,000 acre-feet of groundwater a year, depending on the size of the mineral processing plant.
“Given the substantial changes in local and statewide water conditions since the permit was originally issued, Pima County formally requests that (ADWR) deny renewal of this permit due primarily to adverse effects pumping will cause to the Green Valley/Sahuarita area communities,” Pima County Administrator Jan Lesher states in a Sept. 8 letter to ADWR Director Tom Buschatzke.
“These concerns are certainly more urgent now than when the original permit was issued 19 years ago due to continued groundwater declines and localized land subsidence in the Green Valley/Sahuarita area, statewide Colorado River water supply constraints that impact the ability to offset impacts to pumping, as well as changes to regulatory conditions that afford less protections for groundwater-dependent ecosystems,” Lesher states.
Hudbay is expected to begin the permit renewal process in 2027. Denying the permit would paralyze Hudbay’s plans to develop the sprawling mining project that would destroy the northern half of the Santa Rita Mountains. Hudbay states it intends to develop a series of open pit mines that would operate for an estimated 44 years.
The county’s request comes two weeks after Save the Scenic Santa Ritas filed a formal demand notice with ADWR requesting the agency to require Hudbay to file legally-required aquifer impact studies for four high-capacity wells the company drilled in 2024 and 2025.
ADWR has failed to enforce a state law that requires the studies be filed within 30 days of installing a pump. Hudbay operated the wells in 2025. The reports are supposed to be posted on ADWR’s public website. The information is needed to understand Copper World’s expected impact on the groundwater table. (See SSSR’s Sept. 8 press release.)
“The Copper World mine poses an existential threat to southern Arizona’s long term water supplies and economic future,” says SSSR Executive Director John Dougherty. “ADWR should reject Copper World’s expected application to renew a ground water pumping permit that was first authorized when there was far more water available.”
The Santa Rita Mountains provide renewable surface and groundwater supplies for Tucson and the federally-protected Las Cienegas National Conservation Area east of the range. Hudbay’s groundwater production wells are clustered in and adjacent to the Green Valley Subsidence zone.
The U.S. Bureau of Reclamation identified the Sahuarita/Green Valley as one of four “area(s) of concern” in the Tucson Active Management Area where groundwater levels are expected to decline under all modeling scenarios, according to its 2024 Lower Santa Cruz River Study Final Report.
Lesher notes that Copper World’s current permit for 6,000 acre-feet is enough to supply the average water use for 18,000 households, which is one-and-half times the current number of households in the Town of Sahuarita.
Lesher states that residents living immediately east of Sahuarita in unincorporated Pima County rely on hundreds of domestic wells and are particularly at risk from Copper World’s groundwater pumping.
“Copper World’s withdrawals could cause a rapid drawdown in groundwater that will put the water supplies of these residents at risk without the time necessary to seek assistance from the state,” she said. “The possibility of such a scenario raises significant public health and emergency management concerns for Pima County.”
Hudbay’s Board of Directors has not approved construction of the mine. The board will not consider whether to advance the project until after a final feasibility study is completed. Hudbay announced in July that the study, which was expected to be released this summer, has been delayed until the 4th Quarter.
SSSR is a nonprofit organization dedicated to protecting the Santa Rita Mountains and surrounding communities from the environmental impacts of the proposed Copper World mine.
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