Stakeholder Page- Arizona
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ARIZONA DEPARTMENT OF WATER RESOURCES
With more than 125 years of experience in adapting to one of the most arid climates in the United States and due to our junior priority status on the Colorado River, Arizona has been proactively building resilience and implementing innovative water management strategies to secure dependable water supplies for our future.
Arizona’s population has grown steadily over the years, to more than 5 times and our economy has ballooned to more than 17 times that in 1955, however, through significant investments in conservation, reuse and infrastructure, our water use is essentially the same as it was more than half a century ago.
Arizona leads the nation in the implementation of water efficient reuse programs. More than 95% of treated wastewater generated within Central Arizona (including areas served by the Central Arizona Project and the Salt River Project) serve beneficial uses including agriculture, municipal, groundwater recharge, power generation, industrial, and turf irrigation.
These water supplies support ecologically vital wetland restoration that benefits our unique southwestern flora and fauna, as well as helping to achieve the State of Arizona’s water management goal of Safe-Yield for the Phoenix and Tucson Groundwater Basins.
Water Supplies:
Arizona’s water supplies include water from the Colorado River (including Central Arizona Project Water); instate surface water, groundwater and reclaimed water or effluent. Water supply availability and use varies substantially throughout the State’s planning areas. While groundwater levels in wells may vary over time, groundwater is generally a reliable water supply in most parts of the state while in-state surface water supplies may fluctuate widely from year to year due to precipitation variability. Effluent reuse is increasing and although is represented just 3% of the total water supply in Arizona; it was an important supply in some planning areas.
Colorado River
There is a priority system associated with Colorado River contracts in the event of shortages of supply. Contract priority is an important consideration in water resource planning. The first water to be shorted within Arizona is the CAP and water users’ similar priority along the mainstream of the Colorado River. The Arizona Water Banking Authority (AWBA) was established in 1996 to store unused Colorado River water to meet future needs. The AWBA enabled Arizona to use its full allocation earlier than expected and stores water to be used in times of shortage to firm water supplies for Arizona.
Surface Water
Arizona surface water supplies derive chiefly from snow along the Mogollon Rim and high elevation mountains of east central Arizona and western New Mexico. The Salt, Verde and Gila rivers are essential supplies for water users in central Arizona. The Salt River Project (SRP), through the Salt River Valley Water Users’ Association, annually delivers a total of almost 1 maf of surface water from the Salt and Verde rivers and groundwater to its service area in the Phoenix AMA.
SRP manages several dams on the Salt and Verde rivers that produce hydroelectricity and has substantial surface water right claims in the Salt and Verde watersheds. Water supplies utilized by the towns of Cottonwood, Clarkdale, Camp Verde, Payson and others are derived from the watersheds of the Salt and Verde rivers. The water supplies of the upper Gila River communities of Safford, Thatcher and others are impacted by senior surface water right holders downstream of their communities; the Globe-Equity Decree and by Indian water rights settlements.
Groundwater
With the exception of the Lower Colorado River and AMA planning areas, groundwater is the primary water supply utilized for cultural uses, accounting for approximately 43% of the state’s total water supply annually during 2001-2005. While a number of hydrologic studies and groundwater models have been completed in the AMA’s, there is often less known about the groundwater conditions outside AMA’s where fewer comprehensive studies have been done.
The Department conducts water level and water quality measurements periodically statewide and maintains a repository for statewide groundwater well data. The database includes well log data and historic groundwater level records.
As drought and growth stress the availability of surface water supplies, communities that historically have relied on surface water are exploring groundwater resource options including drilling additional wells and acquiring land for wellfield development.
Effluent
Access to renewable water supplies, especially outside of the AMA’s, may be physically or legally limited. An exception is reclaimed water or effluent, which increases with population growth served by a sewer system. Effluent has met up to 8% of the municipal demand and 27% of the agricultural demand in the Eastern Plateau Planning Area and 28% of the Industrial demand in the AMA planning area. While the percentage of reporting treatment facilities is low in some planning areas, data are available for the largest facilities. Of the 53% of total facilities for which treatment volumes and reuse data are available, 53% of that effluent has been reused primarily for turf irrigation, groundwater recharge, agricultural irrigation and for cooling purposes at the Palo Verde Nuclear Generating Station in the Phoenix AMA.
The highest percentage of reuse is in the Prescott AMA where 91% of the treated effluent is either recharged or used directly for golf course irrigation. A constraint on more reuse is that potential users, such as parks and golf courses, are often distant from treatment facilities and communities lack financing to construct the necessary delivery infrastructure.
