Total Maximum Daily Loads

Positive actions are being undertaken and accomplished to improve water quality in the Chetco, Coos, Coquille and Sixes rivers and area tributaries. We appreciate your interest and involvement. Together we can work towards a better river environment for everyone.

​Chetco Subbasin

TMDL Initiated (Initial scoping and data collection phase)

Coos Subbasin

TMDL Initiated (Initial scoping and data collection phase)


Tenmile Watershed
TMDL Approved by EPA May 31, 2007

Coquille Subbasin


Coquille River
TMDL approved by EPA on July 3, 1996

Upper South Fork Coquille Watershed
TMDL approved by EPA on March 23, 2001

Coquille River Watershed Mapping Tool
The Oregon Coquille River Watershed Total Maximum Daily Load Mapping Tool is designed to help those working to improve vegetated buffers or riparian areas along the Coquille River. The tool allows users to identify high-priority riparian sites and helps ensure enhancements are made in areas where they will improve water quality. The tool shows users the amount of light and heat the sun delivers under existing riparian conditions and how much light and heat an improved riparian area could block. Many manmade and natural factors influence stream temperature. Reducing shade by removing riparian vegetation is just one activity that can contribute to stream warming. Elevated stream temperatures have been shown to limit aquatic life and salmonid and trout rearing and migration.

This tool also provides fish distribution information for multiple fish species and those using the tool can find areas where the potential to improve both water quality and fish habitat is high. Coquille River coho salmon are identified as threatened under the Endangered Species Act. The recovery plan for these fish emphasizes the importance of healthy riparian areas because they provide shade and maintain cool water temperatures for fish. Although riparian plantings take a long time to mature, this tool allows users to preview the potential for improving stream shade over time and provides a unique opportunity to track progress toward improving water quality in the Coquille River. 
Coquille Mapping Tool Instructional Video:
Part 1  |  Part 2  |  Part 3  |  Part 4  |  Part 5  |  Part 6

Sixes Subbasin

TMDL Initiated (Initial scoping and data collection phase)

Garrison Lake
TMDL approved by EPA on Oct. 7, 1988



Acting South Coast Basin Coordinator:
Bryan Duggan, Coos Bay
541-269-2721 x234
Basin Coordinator List