Ottawa 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 41 (Mesotrophic) and was determined using chlorophyll data. For a Deep Headwater lake, this is considered Excellent. Deep Headwater lakes stratify, or form separate layers of water, during the summer months and have a watershed area less than 4 square miles.

Ottawa Lake has been monitored by volunteers since 2002. 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.

Water Quality Reports and Graphs

Station Name	Station ID	Map	Max Year	Reports
Ottawa Lake - Deep Hole	683202	Map	2024	Details
Ottawa Lake - Deep Hole	683254	Map	1980	Details