Deschutes River TMDLs

Summary

On August 6, 2021, EPA transmitted revised final Total Maximum Daily Loads (TMDLs) for the Deschutes River and its tributaries to the State of Washington.

The TMDLs were established on July 31, 2020, to replace portions of the state’s 2015 Deschutes River, Percival Creek, and Budd Inlet Tributaries TMDLs that EPA partially disapproved in June 2018. New TMDLs were developed for sediment, bacteria, dissolved oxygen, pH, and temperature.

EPA’s TMDLs use the Washington Department of Ecology’s original water quality model and data, while calculating new loadings to ensure compliance with Clean Water Act requirements and protection of the water quality standards in Washington.

EPA accepted public comments on the TMDLs from August 7 through October 7, 2020. In response to comments received, EPA revised the TMDLs.

EPA's final TMDL report and supporting documents are available below.

For questions, contact Miranda Magdangal ([email protected]), 206-553-0692; or Lisa Kusnierz ([email protected]), 208-378-5626.

• Deschutes River TMDLs (pdf) (1.86 MB, August 6, 2021)
  TMDLs for sediment, bacteria, dissolved oxygen, pH, and temperature in the Deschutes River, its tributaries, and tributaries to Budd Inlet (July 31, 2020, as revised August 6, 2021).
• Responses to Public Comments on Deschutes River TMDLs (pdf) (783.46 KB, August 6, 2021)
  EPA's responses to comments received during the public comment period August 7 to October 7, 2020.
• Transmittal of Final Deschutes River TMDLs (pdf) (125.02 KB, August 6, 2021)
  EPA's transmittal letter to the Washington Department of Ecology dated August 6, 2021.
• Appendix A: Crosswalk Between Washington’s 2010 and 2012 303(d) Lists (pdf) (193.78 KB)
  Table showing connection between the State of Washington’s 2012 impaired water listings (used in EPA's Deschutes River TMDLs) and their 2010 impaired water listings (used in Ecology’s 2015 Deschutes River TMDLs).
• Appendix B: Capitol Lake Designated Use Evaluation (pdf) (148.39 KB)
  EPA's determination of the applicable aquatic life designated use for Capitol Lake.
• Appendix C: Deschutes River Fine Sediment TMDL Technical Analysis (pdf) (2.63 MB)
  Analysis of key sources of sediment to the impaired segment of the Deschutes River.
• Appendix D: Deschutes River Bacteria TMDLs Technical Analysis (pdf) (4.37 MB)
  Analysis of key sources of bacteria to the impaired tributaries of the Deschutes River and Budd Inlet.
• Appendix E: Deschutes River Mainstem Dissolved Oxygen TMDLs Technical Analysis (pdf) (3.1 MB)
  Analysis of key sources of dissolved oxygen to the mainstem of the Deschutes River in Washington.
• Appendix F: Deschutes River Tributaries TMDLs Technical Analysis (pdf) (3.76 MB)
  Analysis of key sources of temperature, dissolved oxygen, and pH to nine tributaries in the Deschutes River watershed.