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Seven Island 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 39 (Oligotrophic) and was determined using Secchi data. For a Deep Seepage lake, this is considered Excellent. Deep Seepage lakes stratify, or form separate layers of water, during the summer months and have no inlet or outlet.
Seven Island Lake has been monitored by volunteers since 1993. 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 and 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 |
|---|
| Seven Island Lake - Deep Hole | 353168 | Map | 2023 | Details |