Water Quality Index

The Oregon Water Quality Index analyzes a defined set of water quality variables and produces a score describing general water quality for a particular monitoring site in the ambient monitoring network. Scores correspond to a water quality status and are evaluated for improving or declining trends at each site. The status and trend analyses incorporate 10 years (currently water years 2012-2021) of water quality data.

View the Water Quality Index Map

Oregon water quality reports and documents

• 2021 Data Summary
  

• 2020 Data Summary

• 2019 Data Summary
  

• 2018 Data Summary
  

Reference materials

• Story Map: What's in the Water Quality Index?
  
• WQI: Background, Analysis, and Usage  
  

Data downloads

Basin summary tables

• North and Mid-Coast

• Willamette, Sandy, Columbia

• Umpqua, Rogue, South Coast

• Hood, Deschutes, John Day, Umatilla, Grande Ronde

• Powder, Malheur, Owyhee

• Klamath, Closed Basins
  

Raw Data and Historical Status and Trends