ADWR puts finishing touches on latest management plan for Tucson Active Management Area

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The "4MP" as it is known is the latest set of guidelines for the Tucson AMA toward achieving "safe yield"
April 18, 2016

For several years now, the Tucson area has managed to grasp the brass ring of water users in Arizona.

On multiple occasions recently, the "Tucson Active Management Area,"as the region is known, rightfully could claim bragging rights to having achieved "safe-yield" with its groundwater.

Not always. Not consistently. Not yet. But tantalizingly close to consistently, the so-called Tucson AMA has recharged as much or more water back into area aquifers as it has pumped out.


  • The Tucson Active Management Area (AMA) has achieved a balance between groundwater extraction and groundwater recharge in recent years
  • The Arizona Department of Water Resources is putting the finishing touches on the Tucson AMA's "Fourth Management Plan,"a set of guidelines required by law to help AMAs toward their water-management goals
  • Arizona has five AMAs, mostly including the state's most populous regions

Big challenges to safe-yield in the Tucson area remain. The current cumulative volume of grandfathered groundwater-right allotments in the Tucson AMA, for example, far exceeds the amount of groundwater available for pumping under safe-yield conditions.

Still, the area is making progress. From a modern-era peak of over 300,000 acre-feet of groundwater extracted in 1997, groundwater pumping overall has decreased to about half that amount.

The story behind that accomplishment is part of a comprehensive analysis of the Tucson AMA's groundwater use, soon to be published by the Arizona Department of Water Resources in the much-anticipated "Fourth Management Plan for the Tucson Active Management Area."

This "4MP," as it is known, is a management tool designed to help guide the Tucson AMA toward reaching and maintaining safe-yield on a long-term basis. 

Mandated by Arizona's landmark Groundwater Management Act of 1980, this "tool" describes what progress the region has made over the years toward safe-yield, and what more it needs to do going forward to reach its goals on groundwater use by no later than 2025.

"We're focusing on the AMA reaching and maintaining its goal of safe-yield and getting past some of its water-management hurdles,"said Jeff Tannler, the statewide Active Management Area Director for Water Resources.

Tannler's division is responsible for all five of the state's "4MP" documents.

The nearly completed Tucson 4MP will be the second safe-yield roadmap in the current series to be presented by the state's water managers at ADWR. There were three previous series of management plans.

The Prescott 4MP already is complete and published. A draft of the Pinal 4MP is planned for later this year, to be followed by Phoenix and Santa Cruz.

It is the central mission of the landmark 1980 Groundwater Management Act to ratchet back groundwater extraction in most active-management areas until just as much (or more) water goes into the ground as comes out.

Three of Arizona's five active-management areas have safe-yield as their ultimate goal. The Pinal AMA seeks to preserve its agricultural economy for as long as possible. The goal of the Santa Cruz AMA, meanwhile, is to preserve a safe-yield condition and to prevent long-term local water-table declines.

Each of the active management areas (the Prescott, Phoenix, Pinal and Tucson AMAs were established by the Act in 1980, while the Santa Cruz AMA was carved out of the Tucson AMA in 1994) has its own glide path toward its water-management goal -- its own plan of action for getting the job done by 2025.

Every region of Arizona under a management plan has its own unique challenges. The arid highlands that make up the Prescott AMA, for example, must find a way to achieve safe-yield without the benefit of Central Arizona Project water from the Colorado River.

That requires innovative thinking, notes Tannler.

For example, Phoenix has agreed to store a portion of its unused Colorado River water at recharge facilities in the Tucson AMA. In future years, Tucson providers would pump, or recover, Phoenix's stored water. An equivalent volume of Tucson's CAP water, meanwhile, would be delivered to Phoenix directly from the CAP canal.

The cities believe this type of exchange arrangement will provide them flexibility, will save on costs, and will add to the water security of both communities.

The forthcoming "4MP" presumably will help give Tucson's water planners an outline for still more innovation - more progress toward safe-yield.

"I still think the Arizona Groundwater Management Act is landmark in terms of being forward-thinking," said Tannler.


Listen to Jeff Tannler explain the progress of the 4th Management Plan for the Tucson AMA