PHOENIX – New research from Arizona State University and NASA indicates Arizona’s reliance on groundwater is in jeopardy, as underground water storage faces significant depletion.
The findings, however, are met with some disagreement regarding the problem’s extent and its causes.
The research leverages an intriguing scientific method: measuring gravity.
Satellites capable of detecting changes in the Earth’s gravitational field provided data on groundwater levels. Yet, some farmers contend that their on-the-ground measurements do not align with this satellite data.
What they’re saying:
FOX 10 has visited Caywood Farms for years to observe the drought’s impact firsthand.
“Before we ever put a new crop in, we go in and prepare the field so it’s as level as it can be,” Nancy Caywood said three years ago.
Now, Caywood emphasizes their continued significant investment to ensure their flood irrigation methods do not waste water.
“Our fields are dead level from side to side and there’s a slight slope that runs from the irrigation ditch to the end of the field,” Caywood explained.
Despite these efforts, flood irrigation is cited as a major problem in new research by NASA and Arizona State University.
“It was surprising for us, actually, because we found groundwater is being used up much faster than we are expecting,” said Karem Abdelmohsen, an ASU research scientist.
Abdelmohsen stated that researchers used the GRACE satellite to track groundwater in the Colorado River Basin for more than 20 years.
“It does a measurement of change in gravity field. This gravity has a change to sensitivity to any change in water in surface or subsurface,” Abdelmohsen said.
By the numbers:
The study found the Colorado River Basin has lost groundwater equivalent to Lake Mead’s storage capacity in the last 20 years, with 74% of that loss occurring in Arizona. The biggest culprit, they say, is the drought.
“It can be solved, but it can’t be solved only natural. We have to do some other management strategy,” Abdelmohsen said.
The other side:
Next on their list of causes: the agriculture industry and flood irrigation.
“A lot of people think we’re wasting water. A lot of people think we’re not recharging, but we are recharging,” Caywood said.
Caywood points to other data from recent years that shows increasing groundwater levels in some parts of Arizona.
“As farmers, we don’t want to waste water. We think farmers are the best stewards of the land,” Caywood said.
What’s next:
The ASU-NASA research team reports the problem is not slowing down. Their data indicates groundwater was lost three times faster in the last decade compared to the prior decade.
What you can do:
You can click here if you’d like to read more about the research.
DroughtArizona State UniversityNews