Arizona Department of Water Resources

Revision Date: 
Sunday, September 15, 2024

AGENCY CONTACT INFORMATION

Arizona Department of Water Resources

Authority

Established by Laws 1980, Chapter 1, 4th Special Session, effective June 12, 1980. Statutory authority is found in A.R.S. Title 45; §§45-101 et seq. Administrative rules are found at A.A.C. §§R12-15-101 et seq. 

Function

The Department administers all state water laws, except those related to water quality, which come under the jurisdiction of the Arizona Department of Environmental Quality. Created in 1980, the Arizona Department of Water Resources (ADWR) assumed the responsibilities of the Arizona Water Commission and the State Water Engineer relating to surface water, groundwater, dams and reservoirs. 

Statute provides the Director of ADWR with general control and supervision of surface water (including appropriation and distribution) and groundwater (with exceptions spelled out in statute, court judgments or decrees). The Director is also authorized to act on behalf of the state on issues related to the Colorado River. (See A.R.S.§§45-103 and 45-107.) The Department also explores methods to augment water supplies and promote conservation. Arizona’s water supplies include surface water, including Colorado River water and in-state rivers, groundwater and reclaimed water. 

History

The Arizona Territorial Legislature adopted the 1864 Howell Code, which established the doctrine of prior appropriation for surface water, which allocated the right to use surface water for a beneficial use (also referred to as “first in time, first in right”).  Laws 1919, Chapter 164 created the State Water Code and established the office of the State Water Commissioner, who was appointed by the Governor to a six-year term. In 1922, the seven basin states negotiated a compact dividing the Colorado Basin into an upper basin and a lower basin and allocated 7.5-million-acre feet to each basin.  Arizona was allocated 2.8-million-acre feet of water but refused to ratify the compact until 1944. Laws 1943, Chapter 28 transferred the responsibilities of the State Water Commissioner to the State Land Commissioner.  In 1945, the State Land Commissioner was also authorized to administer Arizona’s rights to Colorado River water. See Laws 1945, Chapter 14, 1st Special Session. 

In the 1930s, 1940s and 1950s the Legislature struggled to resolve issues related to groundwater use.  In 1948 the Critical Groundwater Code was adopted, which prohibited drilling new irrigation wells in ten areas of the state designated as ‘critical groundwater areas.”  The 1948 Code did not regulate pumping from existing wells however, allowing groundwater use to continue at historic levels. In response to criticism of the 1948 Code, a second groundwater study commission was formed in 1952. See Laws 1952, chapter 49. None of the recommendations were enacted and the commission was abolished. In 1977, a 25-member Groundwater Management Study Commission was appointed to develop a comprehensive long-range plan for groundwater management by December 31, 1979 (Laws 1977, Chapter 29). 

In June 1980 Governor Babbitt issued a call for a special session to adopt a code to regulate and control the use of groundwater. Laws 1980, Chapter 1, 4th Special Session transferred responsibility to administer Arizona water laws from the State Land Department to a new agency, the Department of Water Resources. The 1980 Groundwater Management Act created four Active Management Areas (AMAs) with specific management goals and requirements to address groundwater overdraft. A fifth AMA (Santa Cruz AMA) was created in 1994 and a sixth, (Douglas AMA) was established in 2022. Among other provisions, the Act imposed restrictions on drilling new large wells within an AMA and required new subdivisions to demonstrate that a 100-year assured water supply is available to support the development. The act also addressed water conservation and transportation of groundwater. 

Since the Department was created in 1980, a number of significant water policies have been enacted relating to conservation, recharge and underground water storage, artificial lakes, water transfer, tribal water rights settlements, interstate water storage agreements, and long-term drought. Some measures expanded Department responsibilities, requiring the Department to provide administrative oversight, issue permits, monitor uses, or track and report data. 

In 1986, the Legislature adopted the legal framework for groundwater recharge projects designed either to augment the groundwater supply (‘recharge projects’) or to store water underground for recovery in the future (‘underground storage and recovery projects’). The measure stated that stored water retained its character as either surface water or groundwater and also stated the ADWR Director was responsible for issuing permits for projects and establishing an accounting procedure for each source of water. The measure encouraged use of renewable water supplies, particularly Arizona’s Colorado River water entitlement through underground storage, savings and replenishment. See Laws 1986, Chapter 289 and Declaration of Policy, A.R.S. §45-801.01. 

The Lakes Bill, enacted in 1987, limited the use of drinking water in artificial lakes constructed in the state’s active management areas. The measure required new lakes larger than an Olympic-sized pool, constructed after January 1, 1987, to be filled with effluent, storm-water runoff, poor quality water or water withdrawn to resolve water logging or water contamination. Certain uses were grandfathered or exempted from the prohibition. See Laws 1987, Chapter 238. 

Groundwater transfers were addressed by Laws 1991, Chapter 212. The measure prohibited moving groundwater from an area outside an AMA to an AMA, unless specifically authorized. Four areas in the state were grandfathered with limitations on the amount of water that could be transferred (McMullen Valley, Butler Valley, Harquahala Irrigation Non-Expansion Area, and the Big Chino sub-basin of the Verde River groundwater basin). See A.R.S. §§45-551 et seq. 

A fifth active management area, the Santa Cruz AMA, which was initially part of the Tucson AMA, was established by Laws 1994, Chapter 296 as an emergency measure. The declaration of policy for its creation is found at A.R.S. §45-411.04. 

The Arizona Water Banking Authority was established in 1996 to facilitate storage of Arizona’s unused Colorado River water, to provide an opportunity to the states of California and Nevada to store their share of unused Colorado River water, to facilitate storage and stored water lending arrangements for entities in Arizona, and to facilitate the settlement of Indian water rights claims by delivering and storing water. See Laws 1996, Chapter 308 and Declaration of Policy, A.R.S. §45-2401. 

The Arizona congressional delegation worked for many years to resolve a number of tribal water claims. Laws 2005, Chapter 143 modified state law in order enact the components of federal legislation that resolved two water rights claims by Arizona Indian Communities: the Gila River Indian Community water settlement and the San Xavier Reservation water settlement. The measure also included the repayment settlement for the Central Arizona Project (CAP) and the water settlement for CAP. 

The Secretary of Interior adopted guidelines in 2007 that provided for coordinated management of Lake Mead and Lake Powell during low water conditions. The seven basin states agreed to allow a water contractor to add water to the Colorado River system through conservation measures, efficiency projects or importation of non-Colorado River water in order to create ‘intentionally created surplus water’ (ICS). In 2007, the Legislature authorized the ADWR Director to enter into an agreement to forbear (decline to exercise) Arizona’s right to intentionally created surplus water (ICS) in the Colorado River system. The forbearance agreement outlined specific conditions related to creation, release and accounting of ICS. See H.J.R. 2001, 48th Legislature, First Regular Session, as transmitted to the Secretary of State. 

The Gila River and Little Colorado River general stream adjudications follow procedures outlined in state law. See A.R.S. §§45-251 through 45-264. The Arizona Superior Court is conducting the lengthy process of quantifying and prioritizing thousands of claims filed by persons and entities within the Gila River system and the Little Colorado River system. ADWR provides legal, technical and administrative support to the Special Master, who is appointed by the court under §45-255.  The General Adjudication Personnel and Support Fund was created in 2021.  Monies from the Fund are available to DWR and the Arizona Supreme Court to hire additional full-time personnel, equipment and services to support the ongoing adjudication of Arizona’s water rights.  See Laws 2021, Chapter 403, Sections 4 and 22. 

Laws 2017, Chapter 189 repealed a section of statute allowing summary adjudication of de minimis surface water uses. The section was repealed in response to an Arizona Supreme Court decision which held the section to be invalid and was replaced by language stating that water rights for small water use claims will be deferred until all other claims in that subwatershed are determined by the Court in the course of the general stream adjudication. See San Carlos Apache Tribe v. Superior Court, 193 Ariz. 195, 972 P.2d 179 (1999) and the San Carlos Apache Tribe Water Rights Settlement Agreement, dated March 30, 1999. 

Laws 2021, Chapter 17 modified the Director’s authority to review assured water supply designations in the Pinal Active Management Area, allows the Director to revise administrative rules relating to assured water supplies, and modified requirements relating to certificates of assured water supply. 

The Drought Mitigation Board and Drought Mitigation Revolving Fund was established in 2021, to provide grants and loans for water supply development projects, conservation development purposes and drought mitigation.  The Board is responsible for reviewing and approving funding requests that substantially improve sustainable water supplies in order to meet the state’s long-term water demand.  The measure outlines the application process and Board procedures. The Board is staffed by ADWR and consists of seven members appointed to five-year terms, with three advisory members. See Laws 2021, Chapter 407.  The Legislature appropriated $160 million from the state general fund to the Revolving Fund in FY 2021, specified that up to $10 million may be used to facilitate the forbearance of water deliveries, and up to $10 million may be used to make the best use of water resources associated with state trust land.  See Laws 2021, Chapter 408. Note: the Board and Fund were repealed in 2022. See entry below.

Laws 2022, Chapter 366 requires the Director to conduct an annual water supply and demand assessment for at least 6 of the 46 groundwater basins in the state. An assessment must be completed for all groundwater basins at least once every five years.  The first assessment is due no later than December 1, 2023 and by December 1 each year thereafter.  The measure appropriated $3.5 million from the state general fund to ADWR in fiscal year 2022-2023 for the assessments.  See Sections 7 and 34.

The measure also repealed the Drought Mitigation Board and Revolving Fund, established in 2021.  Unexpended and unencumbered monies in the Drought Mitigation Revolving Fund were transferred to the Water Supply Development Revolving Fund, except that $10 million, designated in 2021 to facilitate forbearance of water deliveries, was transferred to the Arizona System Conservation Fund.  See Sections 11 and 27.

In June 2023, ADWR completed work on its model for groundwater conditions in the Phoenix AMA and determined “the groundwater flow model projection shows that over a period of 100 years, the Phoenix AMA will experience 4.86 million acre-feet of unmet demand for groundwater supplies, given current conditions” and “…developers seeking new AWS determinations will need to do so based on alternative water sources.”  See the explanation and documentary information compiled by ADWR on its website and on the Arizona Memory Project. The Department proposed the Alternative Path to Designation of 100-year Assured Water Supply (ADAWS) and has proposed draft administrative rules to address the issue. 

Laws 2024, Chapter 225 expands the list of eligible entities allowed to withdraw and transport groundwater away from the Harquahala INA and outlines conditions relating to: monthly reporting requirements; limitations on depth to water and amounts withdrawn per year; hydrology reports; and use of water measuring devices.  ADWR is required to adopt administrative rules to implement the provisions of the measure. An annual report is due to the Governor and Legislative leadership that: 1) provides details on the amount of groundwater withdrawn and transported from the Harquahala INA, and 2) describes the groundwater’s  destination and uses, delineated by eligible entity.  A copy of the report is required to be provided to the Secretary of State.  The measure also expands the use of grant monies from the Water Conservation Grant Fund, administered by WIFA, to include proposals to distribute rebates for gray water systems. 

Chapter 226 allows a city or town located in a designated waterlogged area in the Phoenix Active Management Area to apply to ADWR for an assured water supply designation.  The measure specifies conditions for ADWR to approve the designation.
 

Sources

  • A.R.S.§§45-101 et seq.
  • Arizona Administrative Code §§R12-15-101 et seq.
  • Session Laws
    • Laws 1919, Chapter 164
    • Laws 1943, Chapter 28
    • Laws 1945, Chapter 14, 1st Special Session
    • Laws 1977, Chapter 29
    • Laws 1980, Chapter 1, 4th Special Session
    • Laws 1986, Chapter 289
    • Laws 1987, Chapter 238
    • Laws 1991, Chapter 212
    • Laws 1994, Chapter 5
    • Laws 1996, Chapter 308
    • Laws 2005, Chapter 143
    • House Joint Resolution 2001, 48th Legislature, First Regular Session, as transmitted to the Secretary of State (2007)
    • Laws 2017, Chapter 189
    • Laws 2019, Chapter 1, Chapter 2 and Chapter 263
    • Laws 2021, Chapter 17, Chapter 403, Chapter 407 and Chapter 408
    • Laws 2022, Chapter 366
    • Laws 2024, Chapter 225 and Chapter 226

Arizona Department of Water Resources website

Arizona Memory Project Arizona Department of Water Resources agency collection

Arizona Department of Water Resources annual reports

Surface Water Adjudications

Arizona Department of Water Resources: Alternative Path to Designation of 100-year Assured Water Supply Rulemaking ADAWS (2024)

Arizona Department of Water Resources: Phoenix AMA Groundwater Supply Updates (2023-2024) 

Arizona Memory Project Publication Set Phoenix AMA Groundwater Supply Updates 

Arizona Auditor General Performance Audit and Sunset Review, 2019, Report 19-101

Arizona Auditor General Procedural Review, A Report to the Arizona Legislature, 2005

Arizona Auditor General Procedural Review Letter, 2001

Arizona Auditor General Performance Audit, 1999, Report 99-8

Related Collections At Arizona State Archives

  • RG 59 – State Land Department
  • RG 141 – Interstate Stream Commission
  • RG 142 – Department of Water Resources