The Colorado River cut takes more Arizona water than every industrial user combined

Anyone sizing a fab's water line learns the ratio early. A typical facility might use 10 million gallons of ultra-pure water a day, and making that much can take up to 16 million gallons of municipal water, because deionization and reverse osmosis discard the difference ^[8]. The city system supplies about 1.6 gallons for every gallon the fab uses ^[9].

Set the cut against Arizona's own ledger. The river provides more than a third of the state's water ^[2], and the state is losing more than a quarter of what it draws ^[1]. That works out to roughly 8 to 9 percent of total supply ^[10]. Every industrial user in Arizona, fabs included, accounts for 6 percent ^[6]. Chipmaking has had a foothold in the state since the 1940s ^[7].

"There's not enough water for everything we want to do with it," said Kathryn Sorensen, research director at the Kyl Center for Water Policy at Arizona State University and a former director of Phoenix Water Services ^[22][24]. On how the ranking gets made, Sorensen said: "When there's a water scarcity issue you have to start looking at what the uses of that water are that bring the most value to the community." ^[23] The US Bureau of Reclamation says the basin has faced "unprecedented" drought for more than a quarter century ^[25].

The Verge names no Arizona fab delayed, downsized, or relocated because of water, and it does not weigh water against electricity supply or permitting timelines ^[26]. On this evidence the constraint shows up as cost and as an allocation argument, and no project has been reported stopped.

TSMC says it recycles 65 percent of the water it uses in Arizona, and expects at least 90 percent once it finishes building a water reclamation plant ^[15]. If those shares describe how much of daily use comes from recycled water, the first fab's call on new water falls from about 1.7 million gallons a day to about 475,000 ^[16]. The plant is still under construction ^[15].

TSMC plans at least six fabs in Phoenix ^[13]. Six at the first fab's rate is about 28.5 million gallons a day, or roughly 10.4 billion gallons a year ^[17], and the company says use rises with each new fab and with the more advanced processes it is developing ^[18]. Federal money is behind the buildout: $52.7 billion set aside by the CHIPS and Science Act that President Joe Biden signed in 2022 ^[21], up to $6.6 billion of it awarded to TSMC ^[14], and a $7.86 billion grant to Intel against $32 billion of its own spending on two new Arizona factories and an expansion ^[20].

A siting decision turns mostly on what share of the receiving utility's supply the draw represents, and on whether the consumption figure in the plan depends on infrastructure that is still a construction site. Arizona publishes the numbers for the first in its own water use statistics ^[6]; the second sits on TSMC's reclamation plant schedule ^[15].