Umpqua River Basin Temperature TMDLs

On this page:

• Project summary
• Draft TMDL documents
• How to comment
• Contacts

---

Project summary

EPA is establishing Total Maximum Daily Loads (TMDLs) for temperature in the Umpqua River Basin in southwestern Oregon.

The Umpqua River Basin is comprised of three major rivers – the North Umpqua, South Umpqua, and the Umpqua. These rivers, and numerous tributaries, are identified on the 2022 Oregon Clean Water Act section 303(d) list of impaired waters because of elevated temperature.

Temperature influences critical biological processes for aquatic life, such as survival, growth, reproduction, and behavior. Elevated water temperatures are harmful to aquatic life, particularly salmonid fishes such as salmon and steelhead.

The Clean Water Act requires the development of TMDLs to restore impaired waters to fully support their beneficial uses, such as fish spawning, rearing, migration, and cold water habitat.

A TMDL – sometimes called a water quality restoration plan – is the calculation of the maximum amount of a pollutant allowed to enter a waterbody so that the waterbody will meet water quality standards for that particular pollutant over time.

The Umpqua River Basin TMDL will aim to restore water quality conditions and protect aquatic life by determining the allowable amount of heat from sources in the watershed.

EPA is developing the TMDLs to fulfill a court ordered requirement. The U.S. District Court for the District of Oregon ordered the Oregon Department of Environmental Quality and EPA to replace previously approved temperature TMDLs because of a change in applicable water quality criteria. They will replace the 2006 Umpqua Basin Temperature TMDLs.

The TMDLs are scheduled to be completed no later than February 28, 2025.

Additional information about this project is available on the State of Oregon's website at Temperature TMDL Replacement: Umpqua River Basin.

To learn more about TMDLs, visit Overview of Total Maximum Daily Loads.

---

Draft TMDL documents

• Draft Umpqua River Basin TMDL for Temperature (not including appendices) (pdf) (8.18 MB, October 9, 2024)
  • Appendix A: Current Water Quality Conditions (pdf) (4.53 MB)
  • Appendix B: Seasonal Variation and Critical Conditions (pdf) (1.78 MB)
  • Appendix C: Stream Buffer Width Literature Review (pdf) (2.16 MB)
  • Appendix D: Climate Change and Stream Temperature in Oregon - A Literature Synthesis (pdf) (879.22 KB)
  • Appendix E: Supporting Information for NPDES Permit Writers (pdf) (250.18 KB)
  • Appendix F: List of Restoration Projects (pdf) (115.68 KB)
  • Appendix G: Water Quality Model Calibration & Scenario Reports (pdf) (32.19 MB)

---

How to comment

We are accepting public comments on the draft TMDLs from October 9 through November 25, 2024.

Please submit your comments by email on or before 5pm on November 25, 2024, to Rebecca Veiga Nascimento ([email protected]).

If you are not able to send comments by email, please call Rebecca Veiga Nascimento at 208-378-5767.

After the public comment period closes, EPA will consider all comments received and make edits to the draft TMDLs as appropriate.

---

Contacts

For questions or additional information, please contact Rebecca Veiga Nascimento ([email protected]), 208-378-5767.