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 2006-2015) of water quality data.

Click on the dots to find location information and up to date OWQI results. The meaning of the colors and symbols can be found in the map legend. To search by latitude and longitude, enter the longitude first. 

OWQI Reports and Documents

Reference Materials

Data Downloads

2015 Basin Summary Tables

Raw Data and Historical Status and Trends


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