Decoding Arizona’s Water Language

The world of water is complex, diverse, and full of terminology that can easily confuse anyone who isn't immersed in it regularly. When discussing topics like water quality, water supplies, water management, and policies, you're likely to encounter acronyms and technical language.

We're here to help translate.

Our AMWUA Water Glossary  provides clear and understandable definitions of common water terms to help everyone better understand and participate in Arizona water discussions. Use this guide to gain insight and familiarity with the terminology essential for discussing and reading about water in our State.

Arizona's Critical Water Sources

Each AMWUA city has diverse water supplies to best serve its residents and commercial customers. Having multiple water sources is essential for creating a more resilient and dependable supply for our communities, which directly supports the Valley's economy and our sustainable lifestyle in the desert. 

Arizona has four main sources of water:

Surface Water: Waters generally found in springs, streams, rivers, lakes, ponds, canyons, ravines, or other natural channels above ground. The Salt and Verde Rivers are surface water supplies that serve the AMWUA cities through the Salt River Project (SRP).  

Colorado River Water: Water from the main stem of the Colorado River. Arizona shares the Colorado River with California, Nevada, New Mexico, Utah, Wyoming, Colorado, and Mexico. This surface water is regulated by the Federal Government and delivered to Arizona users by the Central Arizona Project (CAP).

Groundwater: Water under the earth's surface in aquifers. Sole water source for most rural Arizona.

Recycled Water: Water sent down the drain that is treated to a very high quality to extend and expand its reuse. The term is used to convey the value of this water as an essential water supply, also called reclaimed water. Advanced Water Purification (AWP) is an advanced technology and process used to treat and purify recycled water to drinking water standards.

Water Measurements
Understanding water news or reports can be difficult because of the different measurements used. For instance, we use feet, kilometers, and miles for distance, and water is measured by various units depending on the situation.

Acre-foot: A water quantity measurement equal to 325,851 gallons (enough to cover one acre of land in water one foot deep). In Arizona, this is typically enough water for three single-family homes over the course of a year.

Gallons Per Capita Per Day (GPCD): The average quantity of water each person uses in one day. ADWR sets GPCD targets for water providers in the five Active Management Areas (AMAs).

Water Agencies 
Agencies regulate all aspects of water in Arizona, but they are often called only by their acronyms.

Arizona Department of Environmental Quality (ADEQ): The state agency responsible for oversight, regulation, and enforcement of Arizona’s water quality regulations. ADEQ regulates groundwater, surface water, and recycled water.

Arizona Dept of Water Resources (ADWR): The state agency, created in 1980 by the Groundwater Management Act, designated to implement the State’s water laws. ADWR oversees Arizona’s water supplies and supports statewide and local water planning efforts.

Water Infrastructure Finance Authority of Arizona (WIFA): WIFA is the sole state agency responsible for augmentation, following the legislature's 2022 expansion of its authority. WIFA also provides financing assistance for the construction, rehabilitation, and/or improvement of drinking water, wastewater, wastewater reclamation, and other water infrastructure projects.

Water Policies and Laws
In Arizona, we hear important acronyms for laws, policies, and programs that have been established to regulate and manage water across the state and beyond.

Ag-to-Urban: A program that allows farmers to retire their lands for special credits, which entitle the holder to pump a specified volume of groundwater for a Certificate or Designation. This program was established in 2025 and is limited to the Phoenix and Pinal AMAs. 

Alternative Designation (ADAWS): Rules adopted in 2024 that allow an undesignated provider to obtain a 100-year designation of assured water supply. Two water providers (EPCOR-West Valley and Arizona Water Company-Pinal Valley) have become designated under ADAWS.

Assured Water Supply Program (AWS): A set of consumer protection regulations that apply within the AMAs based on the principle of "water first, then development." Before a developer can sell subdivision lots, they must meet the Assured Water Supply criteria, which includes having access to a sufficient water supply that will last for at least 100 years and reduce reliance on groundwater. The AWS Program serves as the foundation for Arizona's long-term, sustainable growth. 

Groundwater Management Act (GMA): Enacted by the legislature in 1980 to address Arizona’s problem of groundwater depletion. The GMA established the Assured Water Supply Program and regulates groundwater pumping through a series of management plans.

The water world is complex, but understanding these terms helps you participate more effectively in decisions that impact our desert communities. We suggest keeping this glossary  nearby for your next water discussion—a vital resource for our long-term sustainability and prosperity here in Arizona.

For additional water terminology, especially concerning the Colorado River, ADWR has compiled a thorough Primer on Water Terminology .

 For 56 years, the Arizona Municipal Water Users Association has worked to protect our member cities’ ability to provide their communities with assured, safe, and sustainable water supplies. For more water information, visit www.amwua.org .