TMDL Title: Temperature TMDLs for the John Day River Basin
Water Quality Limited Parameters: Temperature
Schedule: DEQ will present the John Day River Basin TMDL to the Environmental Quality Commission for proposed rule adoption in March 2026 to give EPA a minimum of 30 days for their approval or disapproval by April 17, 2026.
Project Area: John Day Basin that includes four subbasins: the Lower John Day Subbasin, the Middle Fork John Day Subbasin, the North Fork John Day Subbasin, and the Upper John Day Subbasin.
The project schedule for all replacement temperature TMDLs is online. To stay informed of possible schedule changes and other project related information, please sign up for email updates on our main TMDL Temperature Replacement Project page.
Project summary
In 2013, the United States Environmental Protection Agency 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 USEPA 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.
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Project web page
A Total Maximum Daily Load is a water quality restoration plan and the calculation of the maximum amount of a pollutant that a waterbody can receive while still meeting water quality standards for that particular pollutant. The maximum amount of loading a waterbody can receive is called the loading capacity. Loading from all pollutant sources must not exceed the loading capacity of a waterbody, including an appropriate margin of safety.
The temperature TMDLs for the John Day River Basin will be developed to address temperature listings. The exact extents are described in the Quality Assurance Projects Plans listed below. The TMDL phasing considers the extent of the water quality models being used to support the TMDLs, requirements of the court order, and DEQ's available resources.
Quality Assurance Project Plans: John Day River Basin
A Quality Assurance Project Plan is developed prior to writing the TMDL and does the following:
- Define the issue and objectives of the TMDL, including the spatial and temporal extents of the water quality impairments.
- Provide 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.
John Day River Basin Temperature TMDLs: Modeling Quality Assurance Project Plan
Interactive map
Rulemaking
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.
John Day River Basin temperature TMDL rulemaking
DEQ will hold two rule advisory committee meetings and a public hearing. DEQ will present the draft TMDL and Water Quality Management Plan to the Environmental Quality Commission, DEQ's formal policy and rulemaking body, for adoption before submitting the TMDL to EPA for approval or disapproval.
DEQ will have a rulemaking webpage for rule advisory committee meeting dates and information, draft project documents including the TMDL, Water Quality Management Plan, Technical Support Document, and Fiscal Impact Statement, and to sign up for email updates. Please check back for the rulemaking webpage for updates.
Contact
Michele Martin, Project manager
Trea Nance, Basin Coordinator
Steve Mrazik, Watershed Management Manager