DEQ and the Willamette Basin
Oregon has established Total Maximum Daily Loads, also called water pollution control plans, for the Willamette River and many of its tributaries. These TMDLs identify the level of pollutants that rivers and streams can receive and still meet water quality standards. TMDLs include Water Quality Management Plans that document the ways that landowners, agencies, and others can work to improve water quality.
Extent
The mainstem of the Willamette River meanders 187 miles from south to north before it enters the Columbia River. The Willamette River and its tributaries form the Willamette Basin.