Utility staff monitor the water quality of Echo Lake. Staff monitor for potential health risks such as high bacteria levels and toxic algae as well as other water quality indicators such as temperature, dissolved oxygen and turbidity.

Swimming Beach Monitoring at Echo Lake

• Echo Lake swimming beach is tested for fecal bacteria levels every week in summer, May through September.
• High fecal bacteria levels lead to swimming beach closures; beach closure signs are posted at the lake.
• More information on the King County Swimming Beach Program available here. 

Lake Stewardship: Long-term Trends Monitoring at Echo Lake

King County manages a monitoring program that evaluates long-term trends and changes in many King County lakes, including Echo Lakes. Every other week throughout the summer, a team of volunteer lake monitors gather data and water samples from the middle of Echo Lake.

• Water quality reports from the volunteer effort are available here.
• Interested in becoming a volunteer? Contact Chris Knutson, 206-477-4739. 

A big thanks to our dedicated Lake Stewardship volunteers! From the left: Teena Littleton, Marla Tullio, Paul Michel, Ann Michel, and Jon Polka (not pictured).  

Toxic Algae Monitoring at Echo Lake, Twin Ponds, and Ronald Bog

Harmful algal blooms are overgrowths of algae in water. Algae can appear in various forms and colors. Cyanobacteria, also known as blue-green algae, are bacteria that have some of the characteristics as plants and can pose a toxic threat. Cyanobacteria can look like a paint spill or like grass clippings, and it can cause a thin film along the shoreline or cover a large area of the lake. Green algae, on the other hand, can form thick mats of filaments that can be picked up - these are not cyanobacteria and do not pose a toxic threat.

If you see algae in a City lake, call the City immediately at 206-801-2700 to have it tested. There is no way to tell if an algae bloom is toxic by looking at it. For more information, visit https://www.nwtoxicalgae.org/.

• Toxic algae can lead to lake, pond, or bog closures; closure signs are posted near the waterbody.

Examples of algae observed in Shoreline lakes and ponds. 

The Utility collects and analyzes water quality data for six of the city's major streams. Samples are collected year-round on a monthly basis. Streams sampled include:

• Boeing Creek (east and west forks)
• Ballinger Creek
• Littles Creek
• McAleer Creek
• Storm Creek
• Thornton Creek

Annual reports are available on the King County Water Quality Index for Streams and Rivers webpage.

Photo: Water flowing through Boeing Creek