• Lake Wilderness has very clear water, with low nutrient concentrations and moderate algal growth.
• 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 2023. This is largely due to a peak average N:P ratio in 2011, which recent years have not matched up to.
• Multiple samples from Lake Wilderness were submitted in 2023 for toxin testing. Toxin samples were largely collected through King County’s routine swimming beach monitoring program. In October, toxin testing found elevated microcystin concentrations: 40 µg/L, above the Washington State Recreational Guideline of 8 µg/L.
• Continue to monitor nearshore plants to catch purple loosestrife, a regulated Class B noxious weed that has been identified near Lake Wilderness. If spotted, notify the King County Noxious Weeds Program.
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).
