DEQ Seeks Public Comment on Umpqua River Basin Temperature Plan

The Oregon Department of Environmental Quality is asking for public input on a proposed water quality management plan aimed at addressing elevated water temperatures throughout much of the Umpqua River Basin.

DEQ is proposing amendments to Oregon Administrative Rule 340-042-0090 that would allow the state to adopt a new Water Quality Management Plan implementing the Umpqua River Basin Temperature Total Maximum Daily Load, or TMDL, established by the U.S. Environmental Protection Agency in June 2025.

The project covers the North Umpqua, South Umpqua and Umpqua subbasins. The Little River Watershed is not included in the project area. For purposes of the TMDL, the pollutant being addressed is heat.

EPA says the Umpqua River and numerous tributaries have been identified as impaired because of elevated water temperatures. Warmer water can affect aquatic species, particularly salmon and steelhead, by influencing survival, growth, reproduction and other biological processes.

A TMDL establishes the maximum amount of a pollutant a waterbody can receive while still meeting applicable water quality standards. In this case, the federal TMDL establishes temperature targets and allowable heat loads. DEQ's proposed Water Quality Management Plan is intended to spell out responsibilities and strategies for implementing those targets.

The 2025 Umpqua temperature TMDL replaced an earlier version adopted in 2006. The replacement was required following federal court decisions involving Oregon's temperature standards and a requirement that DEQ and EPA replace 15 temperature TMDLs that had relied on a previously used "Natural Conditions Criterion."

DEQ has been working through the rulemaking process during 2026, including meetings with a rule advisory committee reviewing technical issues and potential fiscal impacts. Draft documents, meeting materials and additional information are available on the Umpqua River Basin Temperature Water Quality Management Plan rulemaking page.

Public Comment Open Through Sept. 24

Anyone may submit comments or questions about the proposed rule changes.

Comments can be submitted by email to umpqua.tmdltemperature@deq.oregon.gov or mailed to:

Oregon DEQ
Attn: Sarah Norpchen
221 Stewart Ave., Suite 201
Medford, OR 97501

The deadline for written comments is 4 p.m. Thursday, Sept. 24, 2026.

Virtual Public Hearing Sept. 22

DEQ will also hold a virtual public hearing at 5:30 p.m. Tuesday, Sept. 22. The meeting will provide an opportunity to learn more about the proposed rules, ask questions and provide verbal public comment.

The hearing can be joined through Zoom. Participants can also call 669-900-6833 and use meeting ID 864 6607 9869.

Additional background on the temperature TMDL, including the geographic scope of the project and technical documents, is available through Oregon DEQ's Umpqua Temperature TMDL Replacement Project and the U.S. Environmental Protection Agency's Umpqua River Basin Temperature TMDL page.

DEQ currently plans to bring the Water Quality Management Plan before the Oregon Environmental Quality Commission for possible adoption in March 2027, although the schedule is subject to change.