Nov 16 2020Share

Taking a Hard Look at Reaching Safe-Yield

By Warren Tenney

In 1980, after decades of severe groundwater declines, State leaders took decisive action when they implemented a regulatory framework to decrease our dependence on groundwater in Arizona's most populated areas. Since that time, Arizona has rightfully boasted about its landmark 1980 Groundwater Management Act. Now, 40 years later, Arizona is again faced with deciding how best to continue to safeguard our groundwater.

To keep us focused and motivated, the 1980 Groundwater Management Act established a goal for the Phoenix Active Management Area (AMA) to reach safe-yield by 2025 and, after that, maintain it. Safe-yield means that the amount of water pumped out of the ground should be balanced by an equal amount that goes back into the aquifer. The 5,545 square mile AMA encompasses the Phoenix metropolitan area, stretching east from the Town of Superior and over 100 miles west to the Tonopah area.

Safe YieldSo are we going to reach the goal of safe-yield? The Phoenix AMA has certainly come far from the dire groundwater overdraft of the 1960s and 1970s that severely depleted our aquifers. Overdraft means more groundwater is being withdrawn than replenished naturally or by our efforts. Nevertheless, we are still experiencing overdraft in the Phoenix AMA, which means we will not reach safe-yield by 2025.

Does it matter that we won't reach safe-yield? This is a question subject to debate. Some believe that the annual overdraft level is minimal, and we should focus instead on our water management successes from the last 40 years. Others view AMA-wide safe-yield as too broad a goal and unsuitable for protecting our aquifers at a more localized level. Still, others feel safe-yield is a useful metric to assess the long-term trajectory of the Phoenix AMA toward or away from groundwater sustainability. Whatever the perspective, it does matter that we won't reach the goal. And no matter how you slice the data or view our progress to date, the bottom line is the well-being of our economy and communities is intrinsically connected to the long-term health of our aquifers.

Acknowledging that we have not completed our journey to safe-yield does not cast doubt on Arizona water management but is rather an honest assessment that we shouldn't rest on our laurels. Continual overdraft, large or small, accumulates over time and will deplete our precious aquifers and the finite volume of groundwater contained within.

Based on our assessment of safe-yield, AMWUA believes that the water community needs to take a hard look at what it would take to reach safe-yield and make a renewed effort to further close the overdraft gap. For 40 years, we have emphasized the importance of reaching safe-yield by 2025. In four short years, we will face scrutiny as to whether we have reached our goal or not. Therefore, it is in the best interest of all water users in the Phoenix AMA – municipalities, agriculture, industry, and others – to collectively deliberate how we can further reduce the cumulative impact of annual groundwater overdraft and better sustain our aquifer health.

This means we start by reaffirming our commitment to sustainable groundwater use as a water community. The principle is simple: as stewards of our aquifers, we should not extract more groundwater than what mother nature (or ourselves) can replace each year. This commitment will require action from all water-using sectors to share in the responsibility of reducing groundwater mining and safeguarding our aquifers. If we endeavor to reduce our collective groundwater reliance by even 100,000 acre-feet per year,  we would be much closer to reaching and then maintaining safe-yield.

It will not be easy to identify and implement new water management strategies to reduce groundwater mining since all water-using sectors rely on some amount of groundwater due to exemptions permitted in the 1980 Groundwater Management Act. This is why ADWR needs to provide strong leadership to guide the water community through difficult but necessary discussions on how we can move away from unsustainable groundwater withdrawals and closer to safe-yield. ADWR's existing Safe-Yield Technical Subgroup provides a logical venue to initiate these discussions and generate ideas and feedback from all water sectors.

This approach will only work if water users and stakeholders are willing to come to the table and work together to identify what actions can be taken. Working to reduce the groundwater overdraft by 100,000 acre-feet will be no small task. If we conclude that we are not willing or able to take new measures to reach the current goal of safe-yield, at least we have had an honest conversation and can then assess what goal and course would better serve how we manage our groundwater beyond 2025. The ten AMWUA cities are fully committed to working with ADWR and the rest of the water community to discuss and craft a path forward to sustainable groundwater use in ways best suited for the Phoenix AMA.

The various interests and leaders who came together to pass the 1980 Groundwater Management Act knew that the foundation of thriving Arizona communities is inextricably linked with the health of our groundwater supplies. With 2025 nearly upon us, the facts remain the same even after 40 years.  When we fail to safeguard our groundwater supplies, all water users, communities, and economies are negatively impacted. When we take steps to sustain our aquifers, we all benefit.

For over 50 years, the Arizona Municipal Water Users Association has helped protect our member cities' ability to provide assured, safe, and sustainable water supplies to their communities. For more information, visit

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