Water right adjudications

Last updated: December 1, 2017

Adjudication is a legal process to determine who has a valid water right, how much water can be used, and who has priority during shortages. It is currently the only definitive and legally binding way to make these determinations.

Adjudication provides a thorough accounting of water which is essential to water resources use, protection and planning, as well as the transfer of water rights. It is key to resolving and preventing conflicts in areas facing increasing demands on water supplies.

The Ecology v. Acquavella et al adjudication

Proposed final decree entered for Yakima River Basin surface water rights case

The historic Ecology v. James Acquavella, et al adjudication determining and confirming all surface water rights in the Yakima River Basin will soon be final.

On August 10, 2017, a Proposed Final Decree and its associated Draft Schedule of Rights was entered into Yakima County Superior Court. The filing sets the stage for final court review of rights conditionally confirmed since 1989 and opens a period to file objections and reviews. Final resolution of the case is expected in the spring of 2018, after which Certificates of Adjudicated Water Rights will be issued.

On August 17, 2017, we mailed notifications including the Proposed Final Decree to all confirmed water right holders. Note: if you no longer own the property associated with this water right,  it is your duty to inform the court of changes of ownership. Please use this form to start this process

Objections to the final decree were accepted until Nov. 15, 2017, and are posted online:

The Yakima River Basin adjudication is the only active adjudication in Washington and covers an area including Benton, Kittitas and Yakima counties, and a small portion of Klickitat County. Filed in 1977, the case will result in the confirmation and prioritization of around 2,300 surface water rights in the Yakima Basin.

Proposed final decrees and schedules


Court documents list

Forms and instructions

The following are forms approved by the Court to divide a water right or to join or substitute owner(s) of property for which a Court claim has been filed:

Other adjudication information

Adjudications can range in size and scope from small (such as the rights of two water right holders with respect to one another) to large (such as the Yakima River Basin) that settle all the rights in a particular water system (a “general adjudication”). They can include surface water, groundwater, or both.

Since 1918, 82 basins have been adjudicated under state water rights adjudication law (See a list of active, completed, and incomplete adjudications; and areas petitioned for adjudication.) There have also been some adjudications under federal law.

Spokane Area Water Right Adjudication

Preliminary work in preparation for a Spokane area adjudication has been completed. Further action leading to a formal start of the adjudication is currently on hold, pending funding and a formal decision to proceed. As Idaho completes their Northern Idaho Adjudication, the Spokane area adjudication is essential to ensuring that Washington rights to shared waters are protected.

Contact information

Leigh Bedell - Staff
(360) 407-6017
  Mike Thomas - Staff
(360) 407-6599
Jenna Rushing - Staff
(360) 407-6041