Water right adjudications
A water right adjudication is the legal process to resolve conflict and competition on a water source. Adjudication legally determines whether each water right on a source is legal, how much water can be used, and its priority during shortages. A watershed-wide adjudication prioritizes each individual water right, including federal, tribal, and instream flow rights, under Washington water law's “first-in-time, first-in-right” prior appropriation framework. When there is not enough water for everyone, those holding the oldest water rights have priority.
Adjudication is an important process to make sure water regulation is fair and everyone follows the same rules.
Current adjudication
On May 1, 2024, Ecology filed the adjudication of WRIA 1 (Nooksack). We selected this area for adjudication through our 2020 Adjudication Assessment.
Read our Frequently Asked Questions for Nooksack Basin.
Whatcom Falls. Photo by Scott Beckner
Past adjudications
In May 2019, the Yakima County Superior Court completed its adjudication process for the Yakima River Basin. This process determined about 2,300 surface water rights for surface water. We are providing water users with adjudicated certificates, which show their water right’s extent (quantity) and priority. The Yakima adjudication is the only general stream adjudication completed for an entire watershed in Washington. However, there have been more than 80 small stream adjudications and multiple federal adjudications. When an adjudication is complete, we can ensure that everyone complies with their legal water right.
Related links
Contact information
Sheila Coughlin
Adjudications
WRAdjudications@ecy.wa.gov
360-255-4406