Water Quality

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. In this map, scores are color-coded to indicate water quality status, and evaluated for improving or declining trends at each site. The status and trend analyses incorporate 10 years (currently water years 2008-2017) of water quality data.

View Water Quality Index Map in a separate window


Oregon Water Quality reports and documents

Reference materials

Data downloads

2017 basin summary tables

Raw data and historical status and trends


Lesley Merrick, 503-693-5724
Dan Brown, 503-693-5743