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Mercer 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 44 (Mesotrophic) and was determined using Secchi data. For a Shallow Lowland lake, this is considered Excellent. 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.
Mercer Lake has been monitored by volunteers since 2001. Volunteers monitor water clarity with a black and white Secchi disk. 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 |
|---|
| Mercer Lake - Deep Hole | 263126 | Map | 2024 | Details |
| Mercer Lake - Home Base | 263177 | Map | 2016 | Details |
| Mercer Lake West Basin Deep Hole | 10022388 | Map | 2009 | Details |
| Mercer Lake at Max Point Of Depth | 263129 | Map | 2009 | Details |
| Mercer Lake in Outlet Bay at Mercer WI | 10037900 | Map | 2008 | Details |