Pursuant to A.R.S. 45-105(B)(14) ADWR is required to conduct a water supply and demand assessment of each groundwater basin in the state at least once every five years, with at least six assessments issued by December 1 of each calendar year. The purpose of these studies is not regulatory, but to improve our understanding of the current and future water conditions and to assist in future planning throughout the state. This information may also inform the distribution of water conservation grant funds. 

The SDRs are structured as water budgets, focusing on total inflows and outflows at the basin scale. The SDRs are not groundwater flow models with finer geographic results, which are conducted by ADWR's Hydrology Division. To create the SDRs ADWR made reasonable efforts to obtain local or specific estimates, but in cases where water data was unavailable staff applied literature values or other types of averages and assumptions to create water use estimates.   

(A.R.S.) § 45-105(B)(14): Not later than December 1, 2023 and on or before December 1 of each year thereafter, prepare and issue a water supply and demand assessment for at least six of the fifty-one groundwater basins established pursuant to section 45-403. The director shall ensure that a water supply and demand assessment is completed for all groundwater basins and initial active management areas at least once every five years. The director may contract with outside entities to perform some or all of the assessments and those outside entities shall be identified in the assessment.  

Reports and Fact Sheets

Groundwater Basin Year Report Fact Sheet
Butler Valley 2023  
Douglas AMA 2023  
Harquahala INA 2023  
McMullen Valley 2023  
San Bernardino 2023  
Tiger Wash 2023  
Willcox 2023  
Methods Appendix 2023  




Methods and Scenarios

ADWR developed and compiled baseline data for the period from 1990-2022. Staff developed scenarios based on the most likely impacts on water demands and supplies projected out over 53 years (from 2023-2075), based on the baseline data.   

These studies reviewed and compiled data for two primary purposes:   

  1. Estimate supply and demand volumes in the basin.   
  2. Project changes in supply and demand from potential future scenarios.   
    1. Status quo: baseline volumes were carried forward through the projection period   
    2. Growth: volumes were assumed to increase within specific parameters through the projection period 
    3. Conservation: volumes were assumed to be influenced by specific conservation practices through the projection period   
    4. Technology: volumes were assumed to be influenced by technological advancements through the projection period   
    5. Climate: volumes were adjusted using a one-degree Fahrenheit temperature increase in the mean annual temperature for the projection period, following a lower emissions pathway for Arizona   



2024 Basins

Supply and Demand 2024 Basins

Agua Fria (AGF)

Big Sandy (BIS)

Cienega Creek (CCK)

Donnelly Wash (DON)

Gila Bend (GIL)

Lower San Pedro (LSP)

Prescott AMA (PRE)

Ranegras Plain (RAN)

Santa Cruz AMA (SCA)

San Rafael (SRF)

Tonto Creek (TON)

Upper Hassayampa (UHA)

Upper San Pedro (USP)

Verde River (VRB)