North Spirit Lake

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 66 (Eutrophic) and was determined using chlorophyll data. For a Shallow Headwater lake, this is considered Fair. Shallow lakes are those that do not stratify during the summer months, so the water near the surface may be impacted by resuspension of sediments. If a lake's watershed is less than 4 square miles, the lake is classified as a Headwater Lake.

North Spirit Lake has been monitored by volunteers since 1986. 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. 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
North Spirit Lake - Deep Hole	513079	Map	2023	Details
North Spirit Lake - Nw Bay Deep	513089	Map	1994	Details
North Spirit Lake - S Bay Deepest	613075	Map	2009	Details