A huge body of water is less than 500 feet away from you just about anywhere in Prescott Valley. Beneath the ground is an aquifer that contains enough water to last hundreds of years at the current level of use. The current rate of use (2014) is about 0.2% of the volume in storage per year. However, the Town of Prescott Valley and other water users are working hard to reduce this overall use to zero - a level that means the aquifer will be sustainable for an indefinite time.
The aquifer beneath Prescott Valley is part of a larger basin that stretches across the area from Chino Valley to the north, to Prescott in the south, and from Granite Mountain in the west to Mingus Mountain in the east. This aquifer is legally designated by the State of Arizona as the Prescott Active Management Area (AMA) Groundwater Basin. The water uses are actively managed by the Arizona Department of Water Resources under the 1980 Groundwater Management Act.
Prescott Active Management Area Groundwater Basin
Key Statistics about the Prescott AMA Groundwater Basin
- Aquifer contains about 2,900,000 acre-feet (950 billion gallons)
- About 10,000 acre-feet per year is recharged
- About 17,000 acre-feet per year is pumped
- Saturated depth under most production wells is estimated to be around 700 feet
- Water levels decline less than 1 foot per year
The 1980 Groundwater Management Act (Act) primarily impacts water providers, such as the Town of Prescott Valley, rather than individual water users. One of the most significant results is that the Act prevents groundwater use for new subdivisions – effectively protecting the groundwater supplies for existing homes and existing platted lots. New subdivisions are required to “bring their own water”, meaning that the developer has to find water sources, such as buying and retiring existing water rights from agriculture or acquiring reclaimed water credits –water sources that are not groundwater by state law. Other significant aspects of the Act include:
- Reaching Safe Yield by 2025
- Mandatory Water Conservation Programs for Water Providers
- No new Irrigated Agriculture from Groundwater
- No new Subdivisions from Groundwater
- Subdivisions must prove they have a 100-year water supply.
- Regular Production of Management Plans to Direct Water Use Policy
- Water Providers and Other Large Users have to Monitor Water Use and Provide Annual Reports
- Reclaimed Water from Wastewater Treatment Used and Managed as an Alternative Water Supply
Although the Act is comprehensive and unifies the regulation of many types of water besides groundwater, the use of water from private wells is exempt from regulation if the wells pump less than 35 gallons per minute. These water users don’t have to monitor or report water use or comply with any conservation programs. As a result, the use of “exempt" wells has proliferated across the Prescott AMA and now number around 10,000, making exempt wells, in total, the third largest water provider in the AMA.
Impacts of the 1980 Groundwater Management Act
The Act has proven its worth in recent times since the area has been under a significant drought since the mid-1990s and has more than doubled its population in that time period. But because of ADWR and its authority under the Act, water use in the Prescott AMA has not increased over the past 50 years. In 1965, the Prescott AMA contained a good amount of irrigated agriculture that depended on groundwater. Because of the regulatory framework, these agricultural uses have been converted to municipal uses and now supply water for homes and businesses. Although some increases to use are likely because of water rights that were granted long ago but not yet put into use, the overall demands on the groundwater system have been capped by ADWR.
Current Annual Use is the same as in the 1960s
Prescott Valley Water Management
The Town of Prescott Valley and the City of Prescott are the two large municipal water providers in the Prescott AMA. Prescott Valley is committed to providing a safe and dependable supply of water to residents and businesses and has taken several important steps to achieving this goal.
One of the more notable goals of the ACT is that of reaching Safe-yield by 2025. Safe-yield is a condition, defined in statute, where the groundwater supplies are stable and no longer declining. This goal, once achieved, will ensure that Prescott Valley residents have a supply of water that will last indefinitely. However, to reach the goal of safe yield, we must reduce our reliance on Prescott AMA groundwater supplies and broaden our portfolio of alternative water supplies. The Town has developed its reclaimed water from the wastewater treatment plant into a useable commodity that can be used for new economic development, yet still support the Safe-yield goal (see Water Reuse page). The Town is also working with the City of Prescott to bring in additional water supplies from a neighboring groundwater basin that will provide an alternate source of water for droughts, help reach Safe-yield and provide water for economic development (see Big Chino Water Ranch Project page). Combined with water conservation measures (see Water Conservation page), the Town’s vitality and the water supplies can be preserved well into the foreseeable future.