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King County Swimming Beach Monitoring


If you have question on this site, please contact Debra Bouchard (206) 477-4650.

Swimming Beach Bacteria and Algal Toxin Levels, and Water Temperature

The following map depicts the locations of current swimming beach sampling stations in King County. To view the current bacteria, algal toxin, and temperature data, either click on the map or select from the list of beaches. Units of bacteria data are cfu/100mL. Algal toxin units are µg/L. To view a list of historical sites monitored, visit the Archived Data link. Current beach closures, if any, are listed right hand column of this page and will appear as red dots on the map. A summary of historical closures can be found on the Historical Closures link.

Andrews Bay - Seward Park
Beaver Lake Beach
Echo Lake
Enatai Beach
Gene Coulon
Green Lake- East
Green Lake- West
Groveland Park Beach
Hidden Lake
Houghton Beach
Idylwood Beach
Idylwood Creek
John's Creek
Juanita Beach
Juanita Creek
Kennydale Beach
Lake Sammamish Beach
Lake Wilderness Beach
Luther Burbank Beach
Madison Park Beach
Madrona Beach
Magnuson Beach
Magnuson Beach Off Leash Area
Marina Park Beach
Matthews Beach
Meydenbauer Bay Beach
Mount Baker Beach
NE 130th Pl
Newcastle Beach
Pine Lake
Pritchard Island Beach
Rattlesnake Lake
Sammamish Landing Beach
Thornton Creek
Waverly Park Beach
Map icon for closed beach  Closed beach   Map icon for open beach  Open beach   Map icon for stream  Stream

Current Beach Closures:

Green Lake- East
Green Lake- West

Green Lake Warning - Avoid Water Contact

Toxic algae has been found in Green Lake and WARNING signs have been placed around the lake. It is advised to avoid water contact.

Animal Safety Alert - Toxic Algae Blooms

Read this article from the Seattle Veterinarian Association to learn about toxic algae and your pet.

BACTERIA AND TEMPERATURE MONITORING ended September 15th. Algal toxins will continue to be monitored throughout October.

Swimmer's Itch Information

Visit Public Health -Seattle & King County  Swimmer's Itch Page to learn about swimmer's itch.

Thornton Creek Bacteria Study

Public warned to stay out of Thornton Creek due to high bacteria levels; based on an intensive study done by the City of Seattle.

We recommend avoiding contact with water from the following creeks: John's Creek, Juanita Creek, Ravenna Creek, Idylwood Creek, and Thornton Creek.