New groundwater research is raising serious questions about the future of rural communities in Arizona.
A study published last week in the scientific journal Geophysical Research Letters shows a rapid acceleration in groundwater usage in the Colorado River Basin in the last decade.
“Much of that groundwater is irreplaceable,” said Arizona State University professor Jay Famiglietti, the lead researcher. “Right? It's fossil groundwater.”
Without major changes in Arizona policy, the state will continue to see accelerated disappearance of groundwater, he said.
“There will be less available for future generations,” he said.
In 20 to 40 years, Famiglietti said, more wells will go dry, and new ones will have to be dug much deeper.
“In short, it will become very expensive to pump that deeper groundwater on our current trajectory, so that only the wealthiest farmers and the biggest farms will be able to afford to pump that groundwater,” he said.
The effects are already being seen in communities like Wenden in La Paz County. Wells are running dry, and residents are already paying up to $130,000 for new ones.
The county is also experiencing subsidence – sinking ground.
“Over the last 15 years, we have dropped over 3.2 feet, and then at an average of like 2.2 inches per year,” Devona Saiter told Gov. Katie Hobbs last week. “It varies at different locations.”
Saiter, whose family has been in Wenden since about the 1960s, owns a shop, and her husband runs the town’s water department.
“My shop, it has sunk in several inches in various locations,” she said. “There’s gaps, there’s cracks.”
Famiglietti said subsidence can happen where a lot of groundwater has been pumped. He compares it to letting air out of a tire.
“Just the way air keeps the tire pumped up, water keeps the land pumped up,” he said.
When water is extracted from the aquifer and the surrounding layers, it’s like air leaving a tire, particularly in regions with a lot of clay minerals.
"Clay minerals are flat, and so when the water that's between them disappears, gets pumped out, then the flat minerals stack up, kind of like dishes in a sink, and that has the impact of lowering the ground surface,” he said.
Subsidence is occurring in southeastern Arizona, as well as California. And it can be really dangerous, Famiglietti said, because infrastructure such as roads and pipes, as well as homes, can be damaged.
He said his research shows that Arizona must now make tough choices.
“It will not be possible to keep doing everything that we're doing everywhere in the state,” he said.“Just, the water is not there to support it.”
That means rethinking the state’s agriculture, and what crops Arizona has enough water to grow.
“What do you want to leave your kids, say in 2060?” he said. “What do you want that groundwater situation to be like?”
