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Lake Mendota
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 56 (Eutrophic) and was determined using Secchi data. For a Two-Story lake, this is considered Poor.
Lake Mendota was monitored by volunteers between 2016 and 2022. 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 |
|---|
| Governor's Island - Lake Mendota | 10052739 | Map | 2024 | Details |
| LAKE MENDOTA NEAR YAHARA R. INLET WATER DEPTH ABOUT 5 FEET | 10031711 | Map | 1997 | Details |
| Lake Mendota - Central Deep Hole | 133318 | Map | 2024 | Details |
| Lake Mendota - Deep Central Region Coring Location | 10046986 | Map | 2016 | Details |
| Lake Mendota - Iota Court | 10058817 | Map | 2024 | Details |
| Lake Mendota - Lake Mendota | 206 | Map | 1970 | Details |
| Lake Mendota - Pheasant Branch Deep Area | 10031991 | Map | 2016 | Details |
| Lake Mendota - West Side | 133536 | Map | 1990 | Details |
| Lake Mendota - Yahara Bay | 10031720 | Map | 2016 | Details |
| Lake Mendota - east end St. Cyr Rd | 10043399 | Map | 2014 | Details |
| Lake Mendota at Burrows Rd | 10043401 | Map | 2014 | Details |
| Lake Mendota at Upham Ct | 10043400 | Map | 2014 | Details |