Lake Margaret

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Lake Margaret		Go to another lake:

Vital Statistics Overview Maps Water Quality Data Related Links

Vital Statistics

Watershed Area	1777 acres
Lake surface area	53 acres
Maximum depth	43 feet
Mean depth	18 feet
Public Park	N
Boat Ramp	Yes, no gas engines
Fish Present	bass, stocked rainbow, cutthro

Volunteer monitoring began at Lake Margaret in 2000 and continued through 2008, after which it was discontinued. The data indicated that this lake was very lightly colored and low in primary productivity (threshold mesotrophic) with very good water quality, varying a little over time but without a firm trend. Lake Margaret is a source of domestic water for homes nearby, making water quality a paramount concern. Profile data show thermal stratification was stable through summer, but sedimentary phosphorus release added little to deep water concentrations. Nitrogen to phosphorus ratios in the upper water were above 20:1, which generally favors other algae species over bluegreens.

Lake Margaret has a public access boat launch, and residents should keep a watch on aquatic plants growing nearshore to catch early infestations of noxious weeds such as Eurasian watermilfoil.

Maps


This bathymetric map shows contour lines of equal depth, similar to a topographic map would for mountains and valleys		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

Click image to enlarge

Water Quality Data

Through a combination of efforts by volunteer lake monitors and King County staff, data relating to physical, chemical, and biological aspects of the lake have been collected for most lakes. The King County Lake Stewardship Program analyzes data to track long-term water quality trends in small lakes in western King County.

View or Download Data
Use this tool to view or download data from the lake in tabular format. You can define date ranges and select which parameters to view or download.

Chart Data
Use the charting tool to look at graphs showing single parameters for a single water year at a time.

Five year water quality trends
A common method of tracking water quality trends in lakes is by calculating the “trophic state index” (TSI) (Carlson, 1977). TSI indicators predict the biological productivity of the lake based on water clarity (Secchi) and concentrations of total phosphorus (TP) and chlorophyll a (Chlor).

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).

Lake Margaret

Vital Statistics

Overview

Maps

Water Quality Data

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