The Central Arizona Groundwater Replenishment District (CAGRD) is statutorily obligated to replenish excess groundwater withdrawn by its members in the Phoenix, Pinal, and Tucson Active Management Areas (AMAs).  CAGRD’s projected future replenishment obligation exceeds the volume of permanent water supplies that CAGRD currently owns.  The primary goal of CAGRD’s Water Supply Program is acquiring a diverse portfolio of water supplies through voluntary, market-based transactions.  CAGRD water supply acquisitions are entirely funded by and solely benefit current and future CAGRD members through annual assessments and a portion of the enrollment and activation fees, not through CAP water rates.  This website provides information and materials about the Water Supply Program including contact information for interested water supply partners.

Program Background

CAGRD is statutorily required to develop a Plan of Operations every ten years.  The 2005 Plan of Operation identified a significant gap between CAGRD’s water supplies and replenishment obligation.  To address the identified shortfalls, the 2005 Plan of Operation set forth water acquisition activities that CAGRD would undertake over the next 20 to 25 years. Following approval of the 2005 Plan of Operation, CAGRD acquired additional CAP M&I and Indian priority supplies as they became available, purchased Long-Term Storage Credits, and initiated discussions to secure multiple effluent supplies.


In 2010, the CAWCD Board adopted a Strategic Plan that included the following strategic objectives regarding CAGRD water supply acquisitions:

  1. re-evaluate the water supply acquisition activities outlined in the 2005 Plan of Operation (e.g., timing, types of supply and projected costs);
  2. aggressively acquire water supplies as outlined in the 2005 Plan; and
  3. develop and implement revenue generation mechanisms (e.g., bonding, rates, fees) that are sufficient to carry out a successful water supply acquisition program.

In March 2011, the CAWCD Board authorized staff to conduct a Water Supply Acquisition Study to support the re-evaluation of the water supply acquisition activities described in the 2005 Plan.  A consulting services contract was awarded to Montgomery & Associates and WestWater Research to provide technical assistance to CAGRD staff to complete the study.  The results of the study were presented to the CAWCD Board in April 2012. 


Based on the Water Supply Acquisition Study, the CAWCD Board in May 2012 directed CAWCD management to implement a more robust CAGRD Water Supply Acquisition Program.  The primary goal of the Program is to acquire a diverse portfolio of water supplies through voluntary, market-based transactions with willing entities.  Since implementation, the program has entered into partnerships with owners of Colorado River entitlements, long-term storage credits, effluent, and CAP supplies.  These transactions have allowed CAGRD to meet its statutory responsibilities to acquire water supplies in a timely and cost-effective manner.


CAGRD’s 2015 Plan of Operation was approved for the Phoenix, Pinal and Tucson Active Management Areas by the Arizona Department of Water Resources (ADWR) on August 5, 2015.  The 2015 Plan of Operation forecasts a CAGRD replenishment obligation of approximately 87,000 acre-feet by 2035. The forecasted replenishment obligation includes currently enrolled members as wells as new enrolment projected through 2024.  The replenishment obligation is anticipated to increase to 113,000 acre-feet by 2114.


As of 2015, CAGRD had acquired water supplies equivalent to an annualized supply of 36,534 acre-feet/year for 100 years.  This supply is sufficient to meet current CAGRD obligations, but some supplies may be reduced when shortage is declared on the Colorado River.  To address forecasted replenishment obligation growth and potential shortage reductions impacting existing water supplies, CAGRD is proactively acquiring both long- and short-term water supplies. 


In 2015, CAGRD and its consultant WestWater Research updated CAGRD’s water acquisition strategy.  The process consisted of updating CAGRD’s inventory of water supplies in Arizona; revising estimates of potentially available supplies and costs to reflect current market conditions; ranking and prioritizing individual water supplies; developing a schedule for pursuing high-priority supplies; and forecasting anticipated costs for comparison to available funds.  This updated strategy will guide CAGRD’s water acquisition activities over the next three years.  Acquisitions will continue to focus on developing a diverse portfolio of supplies, entering into mutually beneficial transactions with willing partners, timing acquisitions to align with replenishment obligation growth, and paying prices consistent with current market rates. 


CAGRD timelineWater Supply Program Timeline

Program Principles

On December 2, 2021, the CAWCD Board of Directors updated a 2013 resolution delineating key principles for the CAGRD acquisition of water supplies to meet its replenishment obligations.  Those principles are:

  1. CAGRD does not have condemnation authority and will not partner with other entities to use their condemnation authority to acquire water supplies through condemnation.
  2. When considering agreements involving Colorado River entitlements held by irrigation districts, CAGRD acknowledges that the districts are the local governmental body best situated to assess any impacts to landowners and farmers within the districts and therefore, will negotiate directly with the districts.
  3. CAGRD will assert its fiduciary responsibility to its members by negotiating a fair and reasonable price for the acquisition of water supplies based on the best available information regarding the fair market value of said supplies.
  4. CAGRD will consider potential third-party impacts to the local community associated with any proposed water acquisition or transfer.
  5. The CAGRD will seek to align long-term storage credit acquisitions with the locations of projected future replenishment obligations
  6. The CAGRD will endeavor, when possible, to partner with member municipalities and water providers on mutually beneficial infrastructure projects to develop or further the use of renewable water supplies.
  7. CAGRD will acquire new water supplies in a manner that generally coincides with increases in CAGRD replenishment obligations as they occur over time.
  8. The CAGRD will seek to acquire a diversified, well-balanced portfolio of short and long-term water assets, including permanent wet water resources (or rights), that will ensure water supply availability under a range of hydrological and operational conditions.

The full resolution is available here.