Originally Published: March 18, 2005 7:10 a.m.
In a recent Courier article, Dava Hoffman presented some of the activities and goals of Prescott's Water Conservation Committee.
Some additional background might add to a better understanding of the issue, how we arrived at this "conservation place" and help develop a vision for what we need to do next.
Most citizens of the region recognize that Prescott depends almost exclusively on a groundwater supply contained within a basin referred to as the Prescott Active Management Area (AMA). But what is the whole story behind our Prescott AMA and what makes it unique from other such areas?
The state of Arizona has 53 groundwater basins. These basins are geologic enclosures that contain varying amounts of groundwater. The 1980 Groundwater Management Act originally recognized four of these groundwater basins as experiencing long-term, excessive depletion (overdraft) and the act designated them as "active management areas." The state established the Santa Cruz AMA, formerly part of the Tucson AMA, in 1994.
The Prescott AMA, which comprises the City of Prescott, the towns of Prescott Valley, Chino Valley and Dewey-Humboldt, contains 485 square miles. Most notably, the population of this region is likely to double by 2026, with water needed to serve more than 150,000 people.
Because of growth and increased demand, the Prescott AMA currently removes about 45 percent more from its groundwater supply than it replenishes. Indeed, of the 105 wells located throughout the AMA that officials monitor regularly, 90 percent experienced water level declines between 2003 and 2004. The average annual water level drop was 2.7 feet. Groundwater level declines of this magnitude are symptomatic of significant aquifer overdraft.
Overdraft (or groundwater mining) occurs when users remove more water from the water-bearing formations (aquifers that make up a groundwater basin) than they replenish (recharge) in the same amount of time. Because water is a very fixed and limited resource in this region, the most immediate consequence of continued overdraft is serious groundwater depletion of our water supply.
Other problems arise from an aquifer overdraft. Among these are the reduction in groundwater storage capacity; uncertainty about future availability of reliable water supplies; the decline of actual groundwater levels which leads to wells going dry, and added drilling and pumping costs that result when water users have to deepen wells. We also must consider diminished flow of natural streams and springs as well as the geological problems that result from earth fissures, cracks and land subsidence.
Because most of these conditions affect our local water situation, the State of Arizona via its Arizona Department of Water Resources (ADWR), has seen fit to apply very strict and assertive water-management programs to our basin to try to protect and preserve our already threatened groundwater resources and supplies.
The management goal for the Prescott AMA is safe yield. This refers to the restoration and subsequent maintenance of a long-term balance between the amount of water that users withdraw and the amount they recharge back to our aquifer.
All programs and related requirements must lead toward a safe-yield goal since the Groundwater Management Act mandates the achievement of this critical aquifer condition by the year 2025.
Reaching safe yield in the Prescott AMA will mandate a variety of water-use policies. Among these are wastewater recovery, treatment and reuse and supplementing our finite water supply through importation projects such as the JWK Ranch purchase that will provide water from a source outside of the Prescott AMA.
Certainly one of the most important of these policies will require a serious and dedicated effort by all water users (big and small) to conserve water and use it wisely.
Gov. Janet Napolitano, in her October 2004 address to the Arizona Town Hall at the Grand Canyon, stated that "we must develop a culture of conservation in Arizona wherein everyone who lives and works here does all that can be done to conserve our most vital natural resource."
That quite simply is the purpose of Prescott's Water Conservation Committee: "defining and creating a culture of conservation."
Water conservation undoubtedly has proven itself a cost-effective and environmentally friendly way to help resolve water-resource problems. Conservation programs have varying levels of success, yet the one thing that is undeniable for the Prescott AMA is that a firm commitment by all municipalities involved is necessary and will most assuredly result in reductions of per capita water use through increased water-consumption efficiency.
In return, such reductions will contribute significantly toward safe yield and the preservation of our most precious groundwater. It's an important and commendable start and certainly one of the best legacies we can leave to future generations.
(Jim Holt is the area director of the Prescott Active Management Area for the Arizona Department of Water Resources, and helps the City of Prescott Water Conservation Committee. He holds a bachelor of science degree in agricultural economics from the University of Arizona and is a 10-year resident of the Prescott area.)
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