Chapter 173-201A WAC (Chelan UAA)

We adopted amendments to chapter 173-201A WAC - Water Quality Standards for Surface Waters of the State of Washington.

We adopted changes to the the following sections:

  • WAC 173-201A-020 (Definitions)
  • WAC 173-201A-440 (Use attainability analysis)
  • WAC 173-201A-602 (Table 602—Use designations for fresh waters by water resource inventory area (WRIA)) to change the designated use and requirements for temperature and dissolved oxygen levels in the water for the Chelan River

We made changes to the aquatic life designated use of salmonid spawning, rearing, and migration on the Chelan River using a use attainability analysis (UAA). A UAA is an approved water quality tool in Washington’s surface water quality standards (WAC 173-201A-440) and is used for removing or revising a designated use for a water body only if that use is not existing or attainable. A UAA is a scientific assessment of the physical, chemical, biological, and economic factors that may affect the attainment of the use.

Rulemaking timeline


Rule proposal phase (CR-102)

Filing date:
March 24, 2021

Rule proposal documents:

Read our press release 

Comment period

We held a public comment period from March 24 to May 21, 2021.

Public Hearings

We held public hearings via webinar on May 11 and May 15, 2021. During the public hearings, we presented our proposed changes, answered any questions, then held the formal hearing to receive oral comments. See above for documents related to the Proposal Phase of the rulemaking.

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