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Lake Susan

Located in Chanhassen, Lake Susan is a part of the Riley Creek Chain of Lakes. It is the third lake that Riley Creek flows through as it makes its way to the Minnesota River.

Lake Susan is classified as a “Shallow Lake” by the MPCA. To be considered healthy, the lake must have very low average phosphorus and chlorophyll-a levels and an average water clarity of 1.0 meters (3.3 feet) or greater.

From June through September every year, District staff visit this and other lakes every two weeks to collect water samples and take readings.  Samples are sent to a laboratory to be tested for nutrients and other compounds. Staff also measure water clarity by lowering a Secchi disk into the water and measuring how deep it goes before it is no longer visible. The data indicates the lake’s health based on standards set by the MPCA.

Lake Susan - Water Quality Grade

Lake WQ Grade D.pngRPBCWD staff assigned this letter grade to the lake based upon how well it is meeting water quality goals. Learn more about lake water quality grades.

For more information about the water quality and grades for lakes monitored in the District, visit the lake factsheets page.

Lake Factsheet

Lake Susan Factsheet

Several water quality parameters are monitored for the lake including Total Phosphorus, Chlorophyll-a, and water clarity. The results are compared to standards set by the MPCA. The District also collects data about native aquatic plant populations and invasive species. Learn more in the lake factsheet.

Open Factsheet

Watershed Location

Lake and Watershed Characteristics

Size 88 acres
Volume 884 acre-ft
Average depth 10 ft
Max depth 17 ft
Watershed size 1281 acres
Land draining directly into 66 acres
MPCA lake classification Shallow
Impairment listing Mercury & Nutrients
Trophic status Eutrophic
Common fish Bluegill, Black Crappie, Northern Pike, Black Bullhead
Invasive species Curlyleaf Pondweed, Eurasian Watermilfoil, Common Carp

For more information about waterbody impairments, visit the Minnesota's Impaired Waters List webpage managed by the Minnesota Pollution Control Agency.

Related Projects

Lake Susan Spent Lime Treatment

RPBCWD and the City of Chanhassen installed a spent-lime treatment system to reduce phosphorus loading into Lake Susan.

Lake Susan Park Pond Project

As part of an ongoing effort to improve water quality in Lake Susan, the District and the city of Chanhassen are teaming up to fund a water filtering and conservation project at Lake Susan Park Pond.

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DNR LakeFinder

Get information on water levels, fish stocking, and water clarity.

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MPCA Surface Water Data

Find historical lake and stream water quality data.

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Metropolitan Council

View and download information on lakes, rivers, streams, rain gauges