A Maricopa County court recently denied Fondomonte’s request to delay Attorney General Kris Mayes’ groundwater lawsuit, reigniting statewide debate over rural water extraction.

The case focuses on whether Arizona’s public nuisance law can impose limits on groundwater pumping. Arizona’s current groundwater framework struggles to address groundwater depletion outside of Active Management Areas.

However, the Fondomonte litigation has exposed a deep structural problem in water management. Arizona lacks a mechanism for allocating groundwater based on the water supply in rural basins. In contrast, we settle water disputes through ad hoc litigation, political battles and piecemeal regulation.

The parameters laid out in Arizona’s Groundwater Management Act don’t fully address overpumping in non-AMA districts. 

The reasonable use doctrine primarily governs water users, but it doesn’t impose quantitative pumping limits or a uniform statutory standard for measuring harm to other users. As a result, litigation often addresses groundwater disputes in rural districts. However, the courts provide after-the-fact remedies rather than effectively allocate water.

Civil proceedings in these disputes are often slow and complex, taking years to resolve. For example, the multi-decade San Pedro River groundwater conflicts have faced continuous pressure from environmental groups and periodic review by the ADWR.

The courts rely on stare decisis, and groundwater cases are fact-specific, leading to inconsistent outcomes even in similar cases and creating uncertainty for water users. Mayes’ high-profile lawsuit against alfalfa producer Fondomonte applies a public nuisance theory to address the dwindling aquifers in La Paz County.

This approach is novel for addressing Arizona groundwater, but it is unknown whether it can yield clear constraints on extraction. Instead of depending on the courts to navigate evolving Tort doctrines, policymakers should pursue mechanisms that allocate pumping rights based on scarcity.

The current regulations for non-AMA water extraction don’t define clear and quantifiable pumping limits tied to aquifer conditions. The ADWR’s lack of authority to impose basin-wide pumping caps in many rural regions of the state compounds the issue — leaving Arizona without a means to allocate groundwater based on scarcity.Lawmakers have attempted to bridge enforcement gaps with various proposals, such as SB1425, which repeatedly stalled before reaching the governor’s desk. 

Arizona lacks one of the strongest safeguards against overpumping, a pricing system that reflects groundwater scarcity. 

One solution for directly tying pumping rights to the water supply would be to implement a system of tradable ground-pumping rights in non-AMA basins. In contrast to having the courts hand down rulings after the aquifer has already been exhausted.

Arizona can use a market-based framework to allocate defined extraction entitlements for trading among water users. Establishing a trading system for rural pumping rights would help to fill this void.

If groundwater prices were allowed to fluctuate with supply and hydrological conditions, water demand would adjust dramatically over time. Because as the water supply decreases, it becomes more expensive to extract water.

Rising extraction costs would make excessive pumping less profitable and create incentives for users to sell extra entitlements, shifting extraction rights towards more efficient water users.

This concept isn’t theoretical — Australia has been doing it since the 1980s with its Murray-Darling Basin (MDB) water market. During Australia’s Millennium Drought, the MDB water market saw peak trading prices in 2007 and a 69% decrease in irrigation water use compared to the early 2000s. Demonstrating that market prices can operate as an effective bulwark against overconsumption when water is scarce.

Mayes’ lawsuit might help clarify the limits of Arizona’s public nuisance doctrine and serve as another tool for preserving groundwater in rural water districts.

However, it has also uncovered a blind spot in the state’s groundwater management approach.

At its core, the state’s challenges are an allocation problem. As groundwater supplies shrink in non-AMA areas, policymakers will need solutions that adapt to water use and aquifer conditions rather than retroactive court proceedings and fragmented regulation.

A groundwater entitlements market would offer a longer-term solution, rather than a Band-Aid response to Arizona’s groundwater difficulties. 

Peter Clark is an Arizona-based writer.