Current Activities

Yamhill Basin Total Maximum Daily Load (TMDL) Review Committee

In August 2009, several Yamhill Subbasin stakeholders met with DEQ as part of a TMDL Review Committee to learn about DEQ’s process for developing pollution reduction targets. DEQ’s water quality analyses will require certain assumptions and data interpretation. The Review Committee members have local knowledge of land use, hydrology, fish use and vegetation that will be helpful to “ground-truth” some of DEQ’s conclusions.

Review committee participants so far include representatives from: Yamhill Basin Council; Yamhill Soil and Water Conservation District; Polk Soil and Water Conservation District; the Cities of Yamhill, Carlton, Lafayette, McMinnville, Dayton, Amity, Sheridan, and Willamina; Yamhill County; Confederated Tribes of the Grande Ronde; The Nature Conservancy; industrial and municipal permit holders; state and federal agencies; and landowners.

The review committee will meet two or three more times over the next 18 months and meeting times, locations and agendas will be posted on this webpage. Between meetings, DEQ may ask committee members to review written material. Please contact the Basin Coordinator, Karen Font Williams, if you have any interest in the Review Committee, attending presentations, or receiving information.

• DEQ Yamhill Subbasin TMDL Presentation to Review Committee, August 2009 PDF

Water Quality Analytical Tools

DEQ will use watershed data in predictive computer models and other analytical methods to develop water pollution reduction targets. One computer model that DEQ will use to analyze stream temperature in the South Yamhill and Yamhill Rivers is called Heat Source. DEQ is beginning to assemble information needed for the Heat Source model such as stream temperature, stream flow, stream channel measurements, and vegetation characteristics along the stream bank.