Pewaukee 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 46 (Mesotrophic) and was determined using chlorophyll data. For a Deep Lowland lake, this is considered Excellent. Deep Lowland lakes stratify, or form separate layers of water, during the summer months and have watersheds greater than 4 square miles in area.

Pewaukee Lake was monitored by volunteers between 1986 and 2020. 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. Pewaukee Lake is also part of DNR's long term trend monitoring project. Additional monitoring has been done through projects funded in part by DNR Aquatic Invasive Species 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
Pewaukee Lake - Auer Bay	10007812	Map	1967	Details
Pewaukee Lake - Deep Hole	683143	Map	2023	Details
Pewaukee Lake - East Basin	10033632	Map	2023	Details
Pewaukee Lake near deepest point	10041745	Map	2019	Details