Surprise 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 49 (Mesotrophic) and was determined using Secchi data. For a Deep Seepage lake, this is considered Good. Deep Seepage lakes stratify, or form separate layers of water, during the summer months and have no inlet or outlet.

Surprise Lake has been monitored by volunteers since 2020. 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 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
Surprise Lake - Deep Hole	433064	Map	2023	Details
Surprise Lake - Surprise Lake	434011	Map	1979	Details