Vol. 28, No. 2
May-August 2020

Welcome to the Arizona General Stream Adjudication Bulletin

The Office of the Special Master publishes the Bulletin three times a year to provide information about proceedings in the Gila River Adjudication and the Little Colorado River Adjudication.



Office of the Special Master
Maricopa Superior Court
Central Court Building 3A
201 West Jefferson
Phoenix, AZ 85003-2205
Tel. 602-372-4115

The Bulletin relies on links so the entire document is available to our readers. Always check our What's New page for up-to-date notices and documents.

Gila River Adjudication



On June 23, 2020, the Arizona Department of Water Resources (“ADWR”) hosted a meeting among members of the ADWR Adjudication team working on developing the Subflow Depletion Test (“Test”), counsel for parties appearing in the case, and experts retained by the parties. The purpose of the meeting was to discuss ADWR’s progress on the development of the Test. At the meeting, ADWR presented its preliminary model, which will consist of three layers. One of the issues that must be resolved is the appropriate location to designate the bottom of the model or, alternatively, a legal definition must be determined of the vertical extent of the subflow zone. An evidentiary hearing is set on this issue to begin on February 22, 2021.


Two issues concerning appropriable rights for water pumped from wells have been designated as issues of broad legal importance. Those issues are:

  1. Is the process set out in the 1919 Arizona Surface Water Code and subsequent versions of that statute the exclusive method for a well owner who has filed a statement of claimant under A.R.S. §45-254 to obtain an appropriative water right in Arizona for water pumped from a well located in the subflow zone with a priority date after June 12, 1919?
  2. Does the adjudication court have equitable powers to decree an appropriative water right for a claimant who began withdrawing water from a well located in the subflow zone after June 12, 1919, but did not comply with the 1919 Arizona Surface Water Code and subsequent versions of that statute?

Briefing is due from claimants by January 11, 2021.


All of the contested cases seeking water rights for irrigation use that can be appropriately initiated at this point in three subwatersheds, Aravaipa, Winkleman, and Redington, have now been initiated. The parties, with the assistance of Arizona Department of Water Resources continue to make progress resolving claims and objections for water rights concerning irrigation uses resulting in the proposed abstracts entered into the catalog of proposed uses. The greatest percentage of completed cases can be found in Aravaipa, with 68% of the irrigation cases completed. Twenty one percent of the irrigation cases have been completed in the Winkleman subwatershed. As irrigation cases were still being initiated during the past four months in the Redington, very few of those cases have proceeded through the process to completion. Three cases are currently set for trial on irrigation issues in addition to the trial scheduled to begin in January 2021 involving the St. David Irrigation District.

Little Colorado Adjudication


Lower Little Colorado Watershed

On May 28, 2020, a status conference was held to establish a procedure to resolve objections filed in response to ADWR’s technical report. No one who appeared at the status conference advocated the need for an evidentiary hearing on the findings made by ADWR about de minimis uses in the Lower Little Colorado Watershed. Currently, ADWR is working on a preliminary hydrographic survey report for the Lower Little Colorado Watershed that will be filed on May 31, 2021.


Link here to the calendar of proceedings.

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