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.
RPBCWD 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 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
|Land draining directly into
|MPCA lake classification
|Mercury & Nutrients
|Bluegill, Black Crappie, Northern Pike, Black Bullhead
|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.
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.
Get information on water levels, fish stocking, and water clarity.
MPCA Surface Water Data
Find historical lake and stream water quality data.
View and download information on lakes, rivers, streams, rain gauges