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Look up individual lakes in King County


Swimming beach water quality

Subscribe to water quality alerts or weekly status of freshwater swimming beaches across King County:

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Lake water quality

Lake maps

Thumbnail map of trophic state of King County lakes

Lake resources, guides and references

Learn about King County's program to protect shorelines, promote public access, and establish priorities for shoreline uses for the county's large lakes, rivers and Puget Sound.

Lake history

  • History of King County's regional wastewater treatment utility
    Read how our region worked to keep our lakes and Puget Sound clean and healthy, including the early days of sewage treatment and disposal in King County, the birth of Metro and development of regional facilities to process the waste produced by our metropolitan area.
  • The birth of Metro (external link)
  • Lake Washington story
    A discussion about the value of Lake Washington, its past pollution problems and subsequent efforts to clean up the lake.
  • Lake Sammamish story
    An overview of Lake Sammamish and its value to people and wildlife, the lake's past pollution problems and subsequent efforts to keep the lake clean.

Lake programs

Related information
Related agencies
News and announcements
Clean Water Healthy Habitat
Clean Water Healthy Habitat
The right investments at the right time in the right places.

Oct. 21, 2019
External article, Seattle Times
6,000 pounds of dog poop a day: Kirkland locked in dirty war 

Jun. 17, 2019
External report, KING5 News
Is that algae safe? How to identify blooms in Washington waters

Spawning Grounds trailer
Documentary about restoring kokanee populations in Lake Sammamish and its tributary streams, by restoring habitat.

Apr. 23, 2019
On Earth Day, Executive Constantine presents Green Globe Awards, the region’s highest honor for local environmental efforts