From the link:

[…]

The amount of water that comes out of Millard Canyon, Christensen said, is relatively small when considered alongside various other canyons and the San Gorgonio River. For that reason, he said, the bottling plant’s impact on the area’s water supplies is probably relatively small.

Davis agreed, pointing out that his agency in 2012 recorded a total of 32,000 acre-feet of groundwater pumped in its entire area, from Calimesa to Cabazon. Compared to that, the estimated 750 acre-feet of water drawn from Millard Canyon represents roughly 2 percent. A single golf course can use more water.

“It’s literally peanuts. It’s a drop in the ocean,” Davis said. “You’re talking about such a small amount of water that it’s kind of ridiculous to fight over that. But people will fight over water no matter what.”

[…]

Looks like bitter local bickering more than a water crisis to me. I read the whole article. It’s long and rambling, with great quotations like this:

“We hear them honking there every night, pulling trucks in and pulling them out,” Wallis said. “We don’t hear nothing from them, just the trucks.”

An article linked to in the middle of that one is about a golf course. Doesn’t say how many acre feet of water they’re using, but they plan to save 200,000 acre feet per year with their new initiative. Makes the estimated 750 acre feet the Morongos are selling (part of) look pretty insignificant.