The Oregon Department of Environmental Quality prepared a geodatabase containing Geographic Information System layers relevant to the Temperature TMDLs for the Willamette Subbasins. The GIS layers summarize TMDL project area, model extents, shade data, data monitoring sites, 303(d) listed waters, and point source discharge locations.

The Willamette Subbasins TMDL for temperature was adopted by the Environmental Quality Commission into rule at OAR 340-042-0090(3) on Aug. 6, 2024. EPA approved the TMDL on Sept. 12, 2024. On May 8, 2025, the EQC adopted a rule amendment to include the Willamette mainstem and major tributaries project area. The rule amendment is pending EPA action by June 28, 2025.

The fish and spawning use designations included in the geodatabase are intended to be as accurate as possible, however some errors may exist. In addition, the Oregon Environmental Quality Commission has approved and DEQ has submitted to the Environmental Protection Agency updates to the fish and aquatic life use designations. As of April 2025, EPA has not taken action on these updates. If approved, these updates will change the fish use designation and applicable temperature criteria for some AUs. In the case of any discrepancy, the applicable temperature criteria and geographic extent described in rule at OAR-340-041 shall take precedence over the layers in the GIS data. In addition, not all monitoring sites supporting CE-QUAL-W2 models developed by USGS (Stratton Garvin et al 2022) are included. Please refer to the USGS reports for summary of data supporting those models.