• Echo Lake continues to have high nutrient concentrations and algal growth, and less clear water.
• Echo Lake’s high nutrient concentrations and nitrogen-to-phosphorus (N:P) ratios below 25 both indicate that Echo Lake is likely to have algal blooms dominated by cyanobacteria (which have the ability to produce toxins).
• An algal bloom was sampled for toxin testing in April, May, October and November. Toxin testing found elevated anatoxin concentrations: 114 µg/L, above the Washington State Recreational Guideline of 1 µg/L. In 2021, Echo Lake was closed due to high anatoxin concentrations from April - May. Echo Lake beach was also closed due to bacteria concentrations for 15 days in August.
This bathymetric map shows contour lines of equal depth, similar to a topographic map would for mountains and valleys. The red 'X' marks the location where water quality samples are taken.
This map shows the area of the watershed relative to the area of the lake. Generally speaking, the larger a watershed is relative to a lake, the greater the influence land use practices on lake water quality.
The average of these three TSI indicators during the growing season can be used
to place lakes in one of three broad categories:
<40 = oligotrophic (low productivity),
40 to 50 = mesotrophic (moderate productivity)
>50 = eutrophic (highly productive).
