Updated Oct. 23, 2025

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Toronto-based Hudbay Minerals’ claims it has a “smart” water management plan with a “goal” to “recharge and recycle as much water as we use” for its planned Copper World mine.

 

On its website, Hudbay states it will achieve this goal “by purchasing water from the Central Arizona Project (CAP) and allowing it to soak into shallow groundwater aquifers from recharge ponds.”  The CAP operates a 336-mile canal that transports water from the Colorado River to cities, farms, and industry in central Arizona.

What Hudbay doesn’t tell you is that it has no chance of meeting its goal. There simply isn’t enough CAP water available and most of what has been acquired so far has been recharged in replenishment basins near Marana, more than 40 miles north of the company’s wellfields in Sahuarita.

 

Since 2007, Hudbay and Augusta Resource Corporation, the previous owner of Copper World when it was known as Rosemont, have purchased 47,810-acre feet (AF) of CAP water, according to the Central Arizona Water Conservation District, which allocates CAP water. This is only about 26% percent of the groundwater Copper World will use over the first 20 years of production, according to a 2022 Hudbay technical report.

 

Hudbay needs the water to process copper ore extracted from a series of open-pit mines on both the east and west sides of the Santa Rita Mountains that will destroy the northern half of the range. The water will also be used to transport toxic mine tailings to waste dumps spread over hundreds of acres south of Corona de Tucson and east of the 52,000-acre Santa Rita Experimental Range.

 

Let’s break this down.

 

Arizona state law exempts mining companies from limits on groundwater pumping. The Arizona Department of Water Resources (ADWR) issues groundwater pumping permits to mining companies, which can be revised.

 

Hudbay currently has a permit from the ADWR to pump up to 6,000 AF of groundwater per year. But the company has projected it will use far more. (An acre-foot of water is equal to 325,851 gallons.)

 

A graphic in Hudbay’s 2022 report states Copper World will require 140 gallons of “fresh water” per ton of ore processed. The fresh water will come from groundwater pumped from the Upper Santa Cruz River Basin which includes Sahuarita and Green Valley. (See Table 1 below).

 

Hudbay plans to initially construct a production plant capable of processing 60,000 tons of sulfide ore per day. At this rate, Copper World will require 8.4 million gallons of fresh water per day – or 9,409 AF per year. (The company has said it could expand production to 90,000 tons per day.)

 

Copper World will become one of the largest consumers of groundwater in Southern Arizona. It will nearly five times more water than the controversial Project Blue data center initially planned to use. During the first 20 years of production, Copper World will require 181,180 AF of groundwater, equal to more than 61 billion gallons of water.

 

Does Hudbay have enough CAP water to replace the groundwater it will use?

 

Not even close.

 

Augusta Resource purchased 45,000 AF of CAP water between 2007 and 2009 - a period of surplus CAP water. But nearly all this water -- 44,441 AF -- was stored at the Lower Santa Cruz Recharge Project near Marana. Groundwater recharged at this facility generally flows northwest, away from Green Valley and Sahuarita. (See Table 2 below).

 

Only 559 AF of CAP water purchased by Augusta Resource was sent to the Pima Mine Road Recharge Project, which recharges the Upper Santa Cruz River Basin beneath Green Valley and Sahuarita.

 

Hudbay purchased Augusta Resource in 2014 and subsequently changed the name of the mining project from Rosemont to Copper World. In 2021, Copper World signed a 10-year annual contract for 1,124 AF of CAP water.

 

The contract is for low-priority CAP water that may not be available. The ongoing mega-drought is sharply reducing Arizona’s share of CAP water. The CAP annual contract only covers about 12 percent of Copper World’s annual projected groundwater demand of 9,409 AF.

 

So far, Copper World has only managed to purchase the full 1,124 AF allotment in 2022, according to the water conservation district. The water was recharged at the Pima Mine Road Recharge Project. Copper World did not purchase any CAP water in 2023 because of reductions in Colorado River distributions. The company has only managed to purchase 843 AF in 2024 and 2025. This water was stored at the Lower Santa Cruz Recharge Project in Marana.

 

To summarize, over the last 18 years the owners of the Rosemont/Copper World mine have purchased 47,810 AF of CAP water for a mine that Hudbay projects will use 181,180 AF of water during the first 20 years. And of this, only 1,683 AF has been recharged into the Upper Santa Cruz River Basin beneath Sahuarita and Green Valley.

 

In other words, Hudbay has replenished less than 1% of the groundwater it intends to pump from Upper Santa Cruz River Basin.

 

What about Project Renews?

 

Another prong of Hudbay’s so-called smart water management strategy is the Project Renews joint venture with Community Water Company to acquire 2,858 AF of CAP water per year. However, the long-delayed project, which will require construction of a pipeline and recharge basins, is only 20% complete, according to Hudbay’s 2024 Annual Report.

 

Community Water Company stated in a 2024 rate increase request filing with the Arizona Corporation Commission that the project is not expected to be completed until 2028. It's uncertain how much CAP water will be available if the project is ever completed. And, whatever CAP water is available is allocated to the Community Water Company, not Hudbay.

 

Hudbay’s “smart” water management plan ignores the reality of Arizona’s escalating water crisis that is resulting in sharp reductions in CAP water. Hudbay’s “goal” to use CAP water to replace all of the groundwater it intends to pump from the Upper Santa Cruz River Basin for Copper World is destined to fail.

 

The harsh reality is Copper World will withdraw tens of billions of gallons of groundwater in the Upper Santa Cruz River Basin with very little of it ever replaced.

 

That’s what Hudbay is hiding from you.

 

John Dougherty

SSSR Executive Director