Colorado River Basin has lost as much water as a full Lake Mead since 2003, study says

A new study has found that over the last 20 years, the Colorado River Basin has lost more than 27 million acre-feet of groundwater – roughly equivalent to a full Lake Mead.

The biggest losses were in the lower basin states like Arizona.

The researchers used NASA's GRACE satellites to detect how much fresh water was in the basin.

They found that since 2003, groundwater was being depleted faster than it could be restored, and that total water loss was accelerating.

In the last 10 years, the water depletion was three times faster than the decade before. The vast majority of the loss was groundwater.

Arizona State University professor Jay Famiglietti co-authored the paper and says the loss comes from climate change, population growth.

“It's in part a lack of management. And if we want to survive and, you know, eat food, because, again, most of our water is used to produce food if we want to be doing that for decades and decades and centuries, now is the time to make those changes," Famiglietti said.

He said more data on the ground, such as well usage rates would help future research.

The paper was published in the journal Geophysical Research Letters.