Arizona water agency moves to establish groundwater protection in La Paz County

Arizona’s water agency is taking the first step toward establishing groundwater protections in La Paz County where water levels are dropping rapidly.

The state Department of Water Resources on Wednesday issued a Notice of Initiation of Designation Procedures — the official start of the process to make a new Active Management Area in western Arizona.

AMAs impose restrictions on water pumping. In this case, it would conserve water in the shrinking Ranegras Plain Groundwater Basin, which also touches a sliver of Yuma County.

The basin is in overdraft, meaning water is being withdrawn from the aquifer more quickly than it’s being recharged. That causes the land to sink and puts water security in jeopardy.

“We know that there are groundwater declines of over 200 feet that have been observed since the 1980s. We've seen significant land subsidence out there in the basin. And we know that land subsidence rates are increasing year over year. So that's the kind of thing that to us shows a serious issue,” ADWR advisor Ben Bryce said.

As of Wednesday, there is a moratorium on irrigation expansion within the basin. That means no new agricultural land can be irrigated until ADWR Director Tom Buschatzke makes a decision on whether to designate an AMA.

If Buschatzke decides not to establish an AMA, the moratorium will be lifted.

A history of AMAs

The 1980 Groundwater Management Act established Arizona’s first four AMAs — Phoenix, Prescott, Tucson and Pinal. The fifth AMA (Santa Cruz) was made from a portion of the Tucson AMA in 1994.

Until 2022, those were Arizona’s only groundwater protection areas.

In 2022, voters in the Douglas area passed a measure to establish the sixth AMA.

In that same election, Willcox area voters rejected a similar proposal. But Democratic Gov. Katie Hobbs’ administration created an AMA in the Willcox basin in 2024.

That was the first time in state history the executive branch made an AMA, and the process is not without controversy.

Agriculture officials and state Republicans accused Hobbs of overstepping by establishing water rules through ADWR instead of state law.

Both Republicans and Democrats agree that the AMA model is not well suited to rural areas, like the Ranegras Plain Basin. They’ve struggled to come to an agreement on legislation for alternative rural management areas for the past few years.

Community response

The next step in the Ranegras Plain AMA process is a public hearing on Dec. 18.

ADWR already held an informal public meeting in La Paz County to discuss the groundwater supply.

Bryce said the community had a mixed response to the AMA idea.

“There are people out there who hope for protections for groundwater. And then there are people out there who know that there's an issue but seem a little unsure about what may be coming. And then there certainly are folks who have said that they are — that they do not want an Active Management Area in the basin,” Bryce said.

La Paz County Supervisor Holly Irwin wishes there was a rural management alternative to AMAs, but said she’s happy the county is getting something in the way of water protection.

“My main focus is advocating for the people that I represent, and you know what, if this is the only tool we can use, then it’s been a long time coming and something that La Paz County definitely needs with this basin,” Irwin said.

She said there’s pushback from the agriculture community, which is a massive water user.

The state of the basins

In 2023, ADWR presented information on three basins of concern, based on aquifer data a few years ago. They were Willcox, Ranegras Plain and Gila Bend.

ADWR focused on Willcox first and is now in process with Ranegras Plain, but the fate of Gila Bend is unclear.

“In Gila Bend, we also held an informal meeting to let folks know about the state of overdraft in the basin and we also answered questions that folks had out there,” Bryce said. “I know there's been some continued conversations that folks out there have had about an AMA. As of right now, we have not initiated proceedings to designate an AMA in the Gila Bend Basin.”