Did you read the article? It was impressively reported and provided a comprehensive account of the problem from a white working class family that relocated to the area and had their well run dry to the backroom discussions in the Arizona legislature that will ultimately dictate the future of industry and environment.
You're right that the Colorado River is irrelevant to the issue under discussion here. But the article clearly shows that the aquifers are as big a crisis:
In the late 1990s, during the first few years of what would eventually turn out to be a 19-year-and-counting Arizona drought, only about 15,000 acre-feet of water were estimated to have percolated into the aquifer each year, while 100,000 were being pumped out; as the valley continued to warm throughout the 2000s and 2010s, with rainfall and snowmelt plummeting, estimates for recharge went unrecorded, as annual pumping soared to 200,000 acre feet. Once, it had been possible for ranchers to develop natural springs into watering holes using only a shovel. Now, after watching water levels drop 100 to 300 feet in 35 years, some farmers wondered how long they could go on... In 2017 alone, one farm pumped 22 billion gallons, nearly double the volume of bottled water sold in the United States annually.
Immigrant laborers and immigration are largely a non sequitur. They're cannon fodder in this battle and scarcely mentioned in the article. They have no say in it. Unless you're talking perhaps about Middle Eastern farming corporations. This is a battle between relatively prosperous local small farmers and bigger corporations:
Arizona was particularly attractive to Middle Eastern farmers. A policy of unregulated pumping on the Arabian Peninsula had, in 40 years, drained aquifers that had taken 20,000 years to form, leaving thousands of acres fallow and forcing Saudi Arabia and others to outsource much of their agricultural production. In 2014, a Saudi Arabian-owned company, the Almarai Corporation, bought 10,000 acres in the town of Vicksburg, northwest of Sulphur Springs Valley, planting alfalfa to ship halfway around the world to feed Saudi cattle. Then, a United Arab Emirates farming corporation, Al Dahra, bought several thousand-acre farms along both sides of the Arizona-California border. These purchases were perfectly legal, but many residents felt these newcomers were essentially “exporting water.”