Sarah Porter thinks about water a lot, as director of the Kyl Center for Water Policy at the Morrison Institute.

So I asked her whether it was nuts for Phoenix to be planning a massive water-bottling plant in the midst of a two-decade drought.

"It seems nuts," Porter said, adding, "It's not really as crazy as it seems."

The Nestlé plant in west Phoenix will bottle millions of gallons of filtered Phoenix tap water in one of the driest states in the nation. The plant will also make the bottles, another water-intensive process.

"If this were a new Coke or Pepsi factory, we wouldn't be having this conversation," Porter said. "If this were a new brewery, we'd probably be celebrating."

Porter's point: Virtually every business that makes something uses a lot of water. The Nestlé plant, whose product is water, focuses attention on manufacturing's need for water.

More importantly, the question of whether the city should support a water-bottling plant is a relatable way for the average person to connect to the drought.

"There is a sort of tension between the messages to conserve water and the knowledge that a big water bottle factory is moving in," Porter said.

Porter noted the coincidence that the news broke the same week that Phoenix and Tucson's main source of water - Lake Mead - hit its lowest level on record. Meantime, Arizona water leaders convened last week to discuss cuts to Colorado River allotments.

A change.org petition rejecting the water-bottling plant had more than 2,300 signatures as of Tuesday.

"I understand the optics of the situation," said Phoenix Water Services Director Kathryn Sorensen.

The Nestlé plant's water use amounts to a drop in the city's collective bucket - less than one-tenth of one percent of the supply, Sorensen said. This will also be the fourth water-bottling plant in Phoenix, city officials said.

"Phoenix is built for drought," she said. "If there's one thing Phoenix knows, it's how to manage our water resources wisely."

The Sierra Club's Sandy Bahr isn't buying it.

"The City is going to say, 'We have plenty of water, don't worry your pretty little heads about this,'" Bahr said.

"We do need to be thinking about that, because we need to be thinking down the road, for the next generation and the one after that and the one after that."

Porter's own questions about the Nestlé plant have to do with water bottles' sustainability issues: the use of a dwindling resource for a product whose containers are made in part from another dwindling resource and clog landfills when consumers dispose of them.

"I try to avoid [water bottles]," Porter said. "I carry a nice double-walled stainless steel bottle around with me all the time."