EPA establishes a temperature restoration plan for the Umpqua River Basin
SEATTLE (June 27, 2025) - The U.S. Environmental Protection Agency is establishing a temperature Total Maximum Daily Load for waters in the Umpqua River Basin. A TMDL is the calculation of the maximum amount of a pollutant (i.e., pollution budget) allowed to enter a waterbody so that the waterbody will meet water quality standards for that particular pollutant over time.
Temperature influences critical biological processes for aquatic life such as, survival, growth, reproduction, and behavior. Elevated water temperatures are detrimental to aquatic life particularly salmonid fishes. This 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 these TMDLs to fulfill a court ordered requirement. The U.S. District Court, District of Oregon ordered the Oregon Department of Environmental Quality and the EPA to establish new temperature TMDLs because of a change in the applicable water quality criteria. This Umpqua River Basin Temperature TMDLs replaces the 2006 Umpqua Basin Temperature TMDLs.
EPA held a public comment period from October 9 - November 25, 2024. EPA’s response to public comments will be published online with the final TMDL documents.
For more information and to view final TMDL documents, visit Umpqua River Basin Temperature TMDL.