A Maricopa County Superior Court judge has invalidated a key Arizona Department of Water Resources rule that developers long relied upon to secure 100-year assured groundwater designations in parts of the Valley where groundwater is the primary available supply. The order, issued Monday by Judge Scott Blaney, strikes down the Alternative Path to Designation of Assured Water Supply rule, a regulatory vehicle intended to allow water providers to meet the state’s 100-year assurance requirement through measures that offset projected groundwater pumping.
The decision removes a formal regulatory pathway that many developers and water providers had counted on when planning projects in outlying communities where surface or reclaimed water sources are not readily available. By voiding the Alternative Path rule, the court has altered the administrative toolkit ADWR had used to evaluate and approve long-term water assurances tied to new development. That has immediate implications for projects already relying on such assurances and for how future proposals will be reviewed while the legal process unfolds.
Illustrative photo: water lapping a rocky shoreline, representing water-resource concerns as a judge sided with developers challenging Arizona groundwater regulations.
Under the rule now struck down, applicants in areas otherwise considered unsuitable for development unless a 100-year assured supply could be shown were permitted to pursue an alternative path: demonstrating that they would provide additional water or take other measures to offset groundwater use tied to a project. That mechanism had been used by developers and water providers to obtain the assurances needed to move forward with housing and related construction in fast-growing outlying communities.
Those alternative measures could include commitments or investments intended to reduce net groundwater depletion attributable to a project, giving regulators a way to certify that, despite reliance on groundwater today, the overall long-term impact on groundwater resources would be mitigated. For decades, Arizona’s regulatory framework has sought to balance long-term resource sustainability with economic and community development needs; the struck-down rule represented one method by which that balance was being administratively managed for certain projects.
Representing the Homebuilders Association of Central Arizona, Holtzman Vogel partner Andrew Gould said the court’s decision removes recent regulatory layers that increased costs for builders and, he said, buyers. "Opens up development now in Buckeye or down in Queen Creek; they don't have the restrictions that were imposed by these rules, and they don't have to pay the extra cost,” Gould said. He framed the ruling as restoring balance between conservation requirements and the interests of stakeholders in homebuilding and housing affordability.
Developers and their trade associations have argued that regulatory requirements layered on top of existing statutes had raised uncertainty and expense for projects on the valley’s edge, potentially limiting the supply of new homes and contributing to higher prices. Gould’s comments reflect the industry perspective that removing the Alternative Path reduces regulatory burdens and can expedite approvals for projects that previously relied on the rule to demonstrate long-term water assurances.
The latest decision follows an earlier ruling from April by the same judge in which he concluded the state’s water department lacked authority to consider groundwater conditions beyond the boundaries of a specific project when reviewing whether a 100-year assured supply requirement was met. That April decision limited the department’s ability to evaluate the broader Active Management Area in its reviews. "If you don't have the authority to write it, you're not allowed to do that under separation of powers," Gould said, citing the court’s reasoning.
By narrowing ADWR’s scope for review, the April ruling effectively constrained the agency from factoring regional groundwater conditions—or the cumulative effects of multiple projects across a wider area—into individual project determinations. That limitation on agency discretion is central to the court’s approach in both decisions and frames the legal debate over how much deference administrative agencies may give to complex, regional water-management considerations when applying statutory mandates to particular development proposals.
The court actions come against a backdrop of state efforts to rein in development in locations that depend solely on groundwater. In 2023 Arizona paused construction in parts of metro Phoenix where groundwater is the only water source after a Department of Water Resources study projected that — under current conditions — groundwater in metro Phoenix would be roughly 4% short of demand over the next century. Those findings prompted tighter scrutiny of new projects relying on long-term groundwater pumping.
That 2023 pause and the underlying ADWR study heightened attention to how the state ensures long-term water availability as metro Phoenix and surrounding communities grow. The prospect of a projected shortfall under existing conditions was used by regulators as a rationale for stricter review of projects that would increase reliance on groundwater, particularly where alternative, renewable supplies were not part of project plans.
Not everyone welcomed the court’s move. Sarah Porter, director of the Kyl Center for Water Policy, said the department’s regulations were intended to ensure that water would be secured before additional growth was allowed. "Groundwater has to be managed as a non-renewable resource, a non-renewing water supply," Porter said. She warned that removing a regulatory pathway designed to confirm water availability before projects proceed "puts at risk not so much the individual well owner on the outskirts of town, what it puts at risk is the groundwater that cities have been counting on as their backup supply." Porter urged municipalities to pursue alternative, renewable sources and pointed specifically to reclaimed water as an option municipalities should continue examining.
Porter’s remarks reflect concerns held by water-policy experts and some public officials that administrative safeguards serve to prevent incremental decisions from collectively undermining regional water resilience. Her urging that municipalities continue examining reclaimed water highlights one of the policy responses advocates say can reduce long-term dependence on groundwater, particularly for non-potable uses and for augmenting other supplies where feasible.
In response to the court’s order, Governor Katie Hobbs’ office released a statement characterizing the decision as a threat to housing development and to water security and announcing plans to appeal. The statement said in part: "Today, the Superior Court issued an order that threatens to shut down housing development and increase housing prices, harms our water security and gets Arizona’s law wrong. While the judgment is not yet final, this order concludes that the voluntary ADAWS program conflicts with statute based on a misreading of both the applicable statutes and the ADAWS rule itself. The ADAWS program is designed to permit responsible growth while protecting our precious groundwater resources.
This program restarted responsible development in Pinal County that had been at a standstill for nearly a decade. Apparently, that achievement was not enough for the plaintiffs who appear to be seeking groundwater pumping without limits.
It may be some time before this ruling is final, but ADWR will appeal.
In the meantime, the State will continue to facilitate responsible, affordable development while protecting Arizona’s best-in-the-nation protections that secure our water future and home values for existing homeowners."
The governor’s office framed the ADAWS program as a voluntary, administratively managed means to allow development to resume in areas that had been stalled, and signaled that the state intends to challenge the court’s legal conclusions. That appeal process will be a key determinant of whether the Alternative Path and the agency’s earlier broader-review authority are ultimately restored, modified or permanently curtailed.
The judge’s orders — both the more recent invalidation of the Alternative Path to Designation and the April decision narrowing the department’s authority to evaluate conditions outside project boundaries — establish a legal landscape that developers say will enable more construction along the valley’s periphery, while water-policy experts and state officials warn of the potential costs to long-term groundwater reserves. With the state signaling an intent to appeal, the ultimate effect of the rulings on housing, development timelines and water management practices will depend on the outcome of that appeal and any further judicial or administrative actions.
For builders and municipalities that had been relying on the regulatory framework the department implemented, the orders introduce immediate uncertainty over pending approvals and the assumptions underpinning long-range planning. For water managers and conservation advocates, the rulings raise questions about how the state will ensure reliable supplies as growth continues, and which policy tools will remain available to address cumulative impacts on groundwater.
Social Media Reactions
Social-media activity on X specifically addressing Judge Blaney’s Monday order has been minimal, largely limited to retweets of Arizona news coverage by local policy observers and water-account handles. No high-profile threaded commentary, verified new facts from officials, or announced initiatives have gained traction beyond recirculation of the governor’s statement and existing groundwater-debate posts.
The muted immediate social-media response underscores that while the rulings have significant regulatory and legal implications, the broader public discussion and any resulting policy shifts are likely to play out over weeks or months as appeals progress, stakeholders respond and agencies consider interim measures.