Lake Koshkonong

Water Quality

One measure of a lakes health is the trophic state, which relates to the amount of algae in the water. The average summer trophic state for the last 5 years was 73 (Hypereutrophic) and was determined using chlorophyll data. For a Shallow Lowland lake, this is considered Poor. Shallow Lowland lakes do not stratify, or form separate layers of water, during the summer months and have watersheds greater than 4 square miles in area.

Lake Koshkonong has been monitored by volunteers since 2001. Volunteers monitor water clarity with a black and white Secchi disk. Some also collect water samples, which are sent to the State Lab of Hygiene to be analyzed. Volunteers are the source of the majority of Wisconsin's lake water quality data, and their dedication is greatly appreciated. Lake Koshkonong is also part of DNR's long term trend monitoring project. Additional monitoring has been done through projects funded in part by DNR Lake Grants. Reports and graphs featuring data collected by volunteers, DNR staff and others can be viewed below.

Water Quality Reports and Graphs

Station Name	Station ID	Map	Max Year	Reports
Lake Koshkonong - Crescent Bay	10043770	Map	2015	Details
Lake Koshkonong - Deep Hole Off South Shore	283119	Map	2024	Details
Lake Koshkonong - Middle Of Lake	543266	Map	2006	Details
Lake Koshkonong - N of Charley Bluff landing	10022780	Map	2024	Details
Rock River at Lake Koshkonong	082	Map	1976	Details