In 1993, the Oregon Legislature passed the Agricultural Water Quality Management Act (Oregon Revised Statute 568.900 through 568.933). 

The legislation directed the Oregon Department of Agriculture (ODA) to develop plans to prevent and control water pollution from agricultural activities and soil erosion on rural lands. ODA is also responsible for ensuring that farmers and ranchers help achieve water quality standards and meet the agricultural pollutant load allocations assigned by the Department of Environmental Quality (DEQ) in their Total Maximum Daily Loads (TMDLs). 

Water Quality TMDLs Program (DEQ website)

Because agricultural pollution is complex with mostly diffuse and diverse sources, Oregon’s Agricultural Water Quality Management Program focuses on landscape conditions that support clean water and healthy watersheds. The Program uses various technical references to identify landscape conditions that should be achieved. The landscape-based approach provides landowners with certainty about their responsibilities and focuses on conditions within landowners’ control.​