King County logo
View WQI scores for another water year (Oct-Sep)  
Map Legend
Low concernLow concern
Moderate concern Moderate concern
High concernHigh concern

Click on the station dot for a link to the most recent WQI score report.

The WQI is a unit-less number ranging from 10 to 100: the higher the number, the higher the water quality.

  • scores 80 and above did not fail water quality standards or guidelines and are of "low concern",
  • scores 40 to 80 indicate "moderate concern",
  • scores below 40 are of "high concern".

Check out the Water Quality Index Background link for more information.