Friendship 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 42 (Mesotrophic) and was determined using chlorophyll data. For a Reservoir lake, this is considered Excellent.

Friendship Lake has been monitored by volunteers since 1994. 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. Reports and graphs featuring data collected by volunteers, DNR staff and others can be viewed below.