Water temperature is a critical attribute of the freshwater habitat of Pacific Northwest salmon and trout. Native salmon and trout require cold water for spawning, rearing and migrating.

State and tribal temperature water quality standards play an important role in helping to maintain and restore the cold temperatures of Northwest rivers and streams to protect salmon and trout and aid in their recovery.

Related Documents

Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards 

The guidance is intended to assist states and tribes in adopting water quality standards for temperature that are consistent with the Clean Water Act and the Endangered Species Act.

• EPA Region 10 Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards (PDF)(57 pp, 281 K, April 2003)

Technical Synthesis

The Technical Synthesis, along with the Technical Issue Papers below, summarizes the science and forms the basis for EPA's temperature guidance referenced above. 

• Technical Synthesis: Scientific Issues Relating to Temperature Criteria for Salmon, Trout, and Char Native to the Pacific Northwest (PDF)(24 pp, 380 K, August 2001)

Cold-Water Refuges Primer

The Primer is a guide for the identification of cold water refuges, which are features of the thermal regime important to salmon and trout.

• Primer for Identifying Cold-Water Refuges to Protect and Restore Thermal Diversity in Riverine Landscapes (PDF)(91 pp, 20 MB, February 2012)

• Columbia River Cold Water Refuges

​Technical Issue Papers

• Issue Paper 1: Salmonid Behavior and Water Temperature (PDF)(38 pp, 303 K, May 2001, EPA-910-D-01-001)
  Supports EPA's 2003 Pacific Northwest water quality temperature guidance.
• Issue Paper 2: Salmonid Distributions and Temperature (PDF)(22 pp, 3 MB, May 2001, EPA-910-D-01-002)
  Supports EPA's 2003 Pacific Northwest water quality temperature guidance.
• Issue Paper 3: Spatial and Temporal Patterns of Stream Temperature (Revised) (PDF)(33 pp, 696 K, October 2001, EPA-910-D-01-003)
  Supports EPA's 2003 Pacific Northwest water quality temperature guidance.
• Issue Paper 4: Temperature Interaction (PDF)(36 pp, 684 K, May 2001, EPA-910-D-01-004)
  Supports EPA's 2003 Pacific Northwest water quality temperature guidance.
• Issue Paper 5: Summary of Technical Literature Examining the Physiological Effects of Temperature on Salmonids (PDF)(118 pp, 829 K, May 2001, EPA-910-D-01-005)
  Supports EPA's 2003 Pacific Northwest water quality temperature guidance.