• In 2024, TSI values were around the mesotrophic-oligotrophic boundary. Mesotrophic lakes (TSI 40–50) have fairly clear water, and moderate nutrient concentrations and algal growth.
• Nitrogen-to-phosphorus (N:P) ratios were below 25 from September through October, indicating times when the algal community was more likely to be dominated by cyanobacteria (which have the ability to produce toxins).
• We are noticing that the N:P ratio trend, while still remaining a significant increasing trend every reporting year, is decreasing in its change per decade from 6.1 (in 2018) to 3.7 change per decade in 2024. This is largely due to a peak average N:P ratio in 2011, which was not reached in recent years.
• An algal bloom was sampled for toxin testing in August. Toxin testing found low concentrations of algal toxins, below the Washington State Recreational Guidelines.
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).
