Stream health results and maps

Macroinvertebrate sampling sites

Each year we sample over 170 sites across King County and, in some cases, outside King County. We have monitored many of these sites since 2002, and we have added others over time. These sites range from very urban areas to remote forest lands. The data for these sites are available on the Puget Sound Stream Benthos database.
 
View King County's B-IBI data. 

Benthic macroinvertebrate monitoring locations as of 2019. 

Long-term trends

We have sampled 120 sites across King County every year between 2002 and 2021. This long-term dataset allows us to track local and regional trends in stream health. Of the 120 sites in the long-term dataset, 30 are showing significant positive trends. These 30 sites are in all categories of B-IBI score: Very Poor, Poor, Fair, Good and Excellent. Only three long-term sites are showing significant negative trends. To view the complete report, click here. 

King County is unique in the nation for having such a comprehensive dataset. This is thanks to our partners in the community for allowing us to sample the same sites year after year. The annual sampling effort is crucial for our ability to track stream health in King County. Each year that we add more data increases our ability to track trends throughout the county.

Status and trends of B-IBI scores at stream sites over the last twenty years.