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Temperature TMDL Replacement: Umpqua River Basin

TMDL title: Temperature TMDLs for the Umpqua River Basin 
Water Quality Limited Parameters: Temperature
Pollutants: Heat
Schedule: TMDL established on June 27, 2025; WQMP under development .
Project area: This project includes the North Umpqua Subbasin, the South Umpqua Subbasin and the Umpqua Subbasin. It does not include the Little River Watershed.

The schedule for all replacement temperature TMDL projects is on the TMDL Project Replacement page, where you can also sign up for email updates, schedule changes and project news. 

Project summary

The U.S. Environmental Protection Agency issued the Umpqua River Basin Temperature TMDL replacement on June 27, 2025, as part of Oregon's statewide temperature TMDL replacement effort. DEQ is now moving forward with the next step – updating the water quality management plan that supports implementation of this TMDL.

In 2013, the EPA disapproved the Natural Conditions Criterion contained in Oregon's water quality standard for temperature due to the 2012 U.S. District Court decision for NWEA v. EPA, 855 F. Supp. 2d 1199 (D. Or., 2012). This portion of the temperature water quality standard was used in most temperature TMDLs issued from 2003 through 2012. On Oct. 4, 2019, the U.S. District Court issued a judgment for NWEA v. EPA, No. 3:12-cv-01751-HZ (D. Or., Oct. 4, 2019) and required DEQ and EPA to replace 15 Oregon temperature TMDLs that were based on the Natural Conditions Criterion and to reissue the temperature TMDLs based on the remaining elements of the temperature water quality standard. 

The updated Umpqua River Basin Temperature TMDL fulfills this requirement. DEQ will now develop a revised  WQMP to describe the implementation responsibilities and strategies for meeting temperature targets established in the TMDL.

green envelopSign up for email updates on the TMDL Replacement Project web page

View the Umpqua River Basin Interactive Map

A Quality Assurance Project Plan is developed prior to writing the TMDL and does the following:

  • Defines the issue and objectives of the TMDL, including the spatial and temporal extents of the water quality impairments
  • Provides a high-level description of the key processes and variables for temperature
  • Outlines the overarching technical approach for the TMDL, including the appropriate modeling and analytical tools to be used
  • Provides the data sources for defining and creating inputs to the models, including data that were used in the modeling for the original TMDLs, if an original exists

Examples of these inputs can include meteorological data, stream flow and temperature, point sources and vegetation characteristics.

  • Describes how the analysis and modeling will be evaluated for acceptability
  • Describes potential scenarios for evaluating management strategies for reducing anthropogenic thermal loads
  • Provides various aspects for managing the TMDL development project, including documentation, the project team, data, and records management​

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DEQ is developing a draft Water Quality Management Plan for the Umpqua River Basin temperature TMDL issued by EPA on June 27, 2025. The WQMP will be completed through a rulemaking process that includes review by a rule advisory committee, public notice and comment, and a public hearing.

Visit the Umpqua WQMP rulemaking page  for information about the rule advisory committee meetings, public hearing, and draft project documents.

Prior public engagement during TMDL development

Between April and October 2024, DEQ and EPA held three webinars on the development of the Umpqua River Basin Temperature TMDL, which EPA issued on June 27, 2025. Materials from the TMDL development phase are available below.

 
Umpqua Temperature Replacement TMDL Meeting #3

Oct. 29, 2024

Water quality staff from EPA presented the draft temperature TMDL for the Umpqua River Basin. This informational meeting was not a public hearing. EPA did not accept public comments during the meeting. To provide public comments visit EPA's web page about this TMDL.  

Umpqua Temperature Replacement TMDL Meeting #2

July 23, 2024

Water quality staff from DEQ and EPA shared their progress on the temperature TMDL for the Umpqua River Basin. The presentation included TMDL development, preliminary wasteload allocations, and schedule toward completion.

Umpqua Temperature Replacement TMDL Meeting #1

April 23, 2024

Water quality officials with DEQ and EPA hosted a webinar on April 23, 2024, and detailed how the agencies plan to revise the temperature TMDL for the Umpqua River Basin. The presentation included TMDL development, public involvement, and schedule.

TMDL development and implementation is a public process. DEQ will develop this TMDL by rule per Oregon Administrative Rule Chapter 340 Division 42. During a rulemaking process, DEQ seeks public involvement by holding public hearings, establishing rule advisory committee meetings for technical and policy input, and for feedback regarding potential fiscal impacts related to the rule.

DEQ will hold two rule advisory committee meetings and a public hearing. DEQ will present the draft Water Quality Management Plan to the Environmental Quality Commission, DEQ's formal policy and rulemaking body, for adoption.

Visit the Umpqua WQMP Rulemaking webpage for meeting dates, materials for the rule advisory committee and public hearing, and draft project documents including the WQMP, rule language, committee charter, and Fiscal Impact Statement. ​

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DEQ contacts

Sarah Norpchen
Basin Coordinator 
541-774-5905

Steve Mrazik
Watershed Management Manager
503-229-5379

Ranei Nomura
Manager - Wastewater and Individual Permits
503-378-5081

envelopeGreen.gif Sign up for email updates on TMDLs.

EPA contacts

Jenny Wu
Watershed Section Manager
206- 553-6328

Rebecca Veiga Nascimento
Technical Lead
208-378-5767