by Zachary P. Sugg, PhD, Visiting Assistant Professor, Southwest Studies, Colorado College
It is well-known that Arizona has made significant progress towards reducing groundwater overdraft where groundwater depletion has historically been most severe, the designated Active Management Areas. Nevertheless, achieving and sustaining the safe-yield goal of the three urbanized AMAs (Phoenix, Prescott, and Tucson) seems far from certain. It is also important to remember that safe-yield is assessed at the scale of entire AMAs. This means that as long as overall withdrawals are balanced by “deposits”, compliance is achieved. This can potentially mask the unevenness of hydrologic conditions within AMAs. Areas of long-term decline may worsen while conditions in other areas improve. Even if safe-yield is attained by the time the last management period ends in 2025, important problems resulting from groundwater pumping may persist within certain parts of an AMA. In this short article I wish to draw attention to this issue, characterize the problem, and point out some ideas for responding to it.
During the past three years I conducted research comparing groundwater governance in the metro Phoenix region with the San Antonio, Texas metro area. Through this experience I had the opportunity to speak with a number of Arizona’s water experts. Based on these conversations and a number of groundwater planning documents I reviewed, I recognized a key issue was the challenge of devising robust planning systems for addressing groundwater-related problems at the scale of critical areas and sub-areas within AMAs.
Various studies have documented water table declines in the Phoenix AMA. Groundwater pumping in both sides of the Salt River Valley has generated areas of subsidence, earth fissures, and aquifer compaction with irreversible losses in storage capacity. In the West Valley, major areas of depletion are located just east of the White Tank Mountains and under the city of Glendale. Areas of problematic cones of depression have also been identified in the East Valley sub-basin. A study conducted under the auspices of the East Valley Water Forum identified areas of significant drawdown. Based on modeling work by the Arizona Department of Water Resources (ADWR), the study projected that full use of recharge facilities may not be sufficient to ameliorate long-term water table declines in the East sub-basin.
Additionally, new issues may be developing. Some municipal water managers in the Phoenix metro area expressed concern about the hydrologic consequences of increased pumping in groundwater-dependent exurban areas on the outer fringes of aquifers in the Phoenix AMA.
Given these well-known problems, the need for more coordinated planning and management at the sub-AMA scale to address critical areas has been repeatedly identified over the last 15 years. In 1999, ADWR stated in the 3rd Management Plan for the Phoenix AMA that it was necessary “to address long-term water issues on a subregional or ‘critical area’ basis.” The Arizona Governor’s Water Management Commission also identified this issue in its 2001 final report. Although the Commission considered two different ways of addressing the issue, it was unable to agree on a single recommendation. A lack of action was pointed out by the 2004 report of the Arizona Town Hall and again in a 2008 study by Sharon B. Megdal and others. Following this series of reports, and public comments on draft 4th Management Plans, ADWR stated in its 2013 annual report its intention to recognize local conditions and sub-area issues.
Despite longstanding recognition from various reports, studies, and convened expert groups, there appears to remain a lack of robust formal groundwater planning at the sub-AMA level. How might it be addressed?
Several ideas and efforts are worth consideration. As noted above, the Governor’s Water Management Commission considered two proposals. One was the designation of “critical areas” within the AMAs where a specific groundwater issue exists. Under this approach, “‘critical areas’ would be specifically identified and then programs developed and implemented to provide heightened levels of water management. For example, a potential new program might limit issuance of new withdrawal authorities within the boundaries of certain critical areas.” This approach was opposed by some Commission members over concerns about “the adverse impacts on the value of land, potential legal implications, and the stigma that could become attached to areas identified as critical.” The Commission also considered a “safety net” approach, which would consist of adding “conditions to current AMA wide programs that seek to prevent or mitigate particular localized problems.”
One example of sub-AMA municipal cooperation is the West Valley Central Arizona Project Subcontractors, or WESTCAPS. However, WESTCAPS is primarily oriented towards water augmentation and infrastructure planning for groundwater-reliant West Valley communities. In the East Valley, the East Valley Water Forum (EVWF) was established in 2001 and has broader goals and representation than WESTCAPS, including not only municipal water utilities, but also the Salt River Project, irrigation districts, and Native American tribes. The EVWF has conducted planning exercises for the entire East Valley urban region with groundwater modeling support from ADWR. The organization identified critical areas and proposed ideas on how conditions, such as large cones of depression, may be improved under certain future scenarios of recharge and utilization of renewable supplies.
While some tentative efforts at facilitating sub-AMA and critical area groundwater planning do exist within Arizona, it may also be worthwhile for Arizona to look further afield for ideas. Elsewhere in the Western U.S. there is an emerging shift towards decentralized (i.e., localized or “bottom-up”) forms of groundwater governance. Such bottom-up efforts now dot the West. They are sometimes officially state-sanctioned and in other cases are more informal. One example is the formal bottom-up system developed in Texas after decades of relatively minimal groundwater management. In this system, local groundwater districts are grouped into regional groundwater management areas by the Texas Water Development Board (TWDB), based primarily on hydrologic boundaries. State law currently requires joint groundwater planning at a regional scale by managers of local districts with input from the public. The public is able to voice concerns about proposed management goals (or revisions to them) at public meetings. Final management goals are submitted to the TWDB, which then uses hydrologic models to determine physical feasibility at the scale of the groundwater management areas and, in some cases, individual groundwater districts, and how much groundwater is available to allocate to users and still achieve regional goals. Goals are then revisited and revised, if desired, every five years. Although the planning system is still fairly esoteric (even within Texas), it represents a major shift towards more coherent, regional-scale thinking about groundwater management challenges in a state known for a highly hands-off approach. Features of the Texas system include:
- It does not require constant labor from state agency staff. TWDB’s role is primarily one of oversight and technical support;
- It provides a formal, iterative goal-setting and revision process conducted by publicly elected representatives;
- It allows for public input on groundwater management goals;
- It creates a decision-making space within which special management goals could potentially be adopted to address critical area problems;
- It is premised on a broad focus on management and planning rather than strictly water augmentation and infrastructure.
This is just one example of a bottom-up groundwater planning system in the West and it is not without its limitations. Other states that have opted for decentralized groundwater governance approaches are Nebraska and, more recently, California, with the passage of the Sustainable Groundwater Management Act of 2014. These approaches may also be instructive.
As Arizona moves beyond safe-yield towards long-term sustainability more broadly, it will be critical to find ways to increase the capacity to address problems that can exist even in safe-yield condition. Arizona must also develop ways of effectively addressing critical area problems not just within AMAs, but statewide, as growth in certain areas continues to increase demands on groundwater where the resource is less strictly regulated. Arizona’s water leadership may wish to revisit the work done 15 years ago by the Governor’s Water Management Commission. The East Valley Water Forum may also provide an instructive example worth replicating in some form or fashion in other AMAs and perhaps outside of the AMAs. Arizona may also benefit from looking at efforts taken by other Western states in recent years to address similar types of groundwater problems. I have highlighted Texas’s recently developed system as one example.