Door County Lake Quality
Wisconsin, 11 lakes, average grade B (Good)
Only 11 lakes in Door County carry an active grade. The county-level summary is therefore representative of those specific lakes, not necessarily of every water body in the county. With an average grade of B, Door County sits comfortably above the Wisconsin median.
Most of the county's monitored lakes are shallow — under 50 feet — which means wind keeps the water column mixed all summer and sediment-bound phosphorus releases back into the surface layer whenever the bottom is disturbed. Clark Lake (A) is the cleanest in the county.
Quick Answers for Door County
Planning a trip? Check special fishing regulations for Clark Lake, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
DNR Reports (7)
Wisconsin DNR Fisheries Survey resources for lakes in Door County. browse all reports →
- 2024Forestville Millpond spring shocking survey, 2024Spring Shocking Survey · WI DNR · 2024 (PDF)
- 2023Europe Lake comprehensive survey, 2023Comprehensive Survey · WI DNR · 2023 (PDF)
- 2023The smallmouth bass sport fishery, Rowley Bay, 2016, 2018, 2023Fisheries Survey · WI DNR · 2023 (PDF)
- 2022The smallmouth bass sport fishery, Washington Island/Detroit Harbor, 2014, 2022Fisheries Survey · WI DNR · 2022 (PDF)
- 2021The smallmouth bass sport fishery in Sturgeon Bay/Little Sturgeon Bay, 2017, 2021Fisheries Survey · WI DNR · 2021 (PDF)
- 2016Forestville Millpond Fish Survey 2016Fisheries Survey · WI DNR · 2016 (PDF)
- —Smallmouth bass assessments in Door County, 2009-2012Fisheries Survey · WI DNR (PDF)
All Lakes in Door County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Clark Lake | A | 12.5 ft | 25 ft | 10.5 µg/L |
| 2 | Kangaroo Lake | B | 8.8 ft | 12 ft | 13.2 µg/L |
| 3 | Dunes Lake Just Us of Outlet | B | - | - | 24.1 µg/L |
| 4 | Inlet To Dunes Lake | B | - | 1 ft | 28.9 µg/L |
| 5 | Europe Lake | B | 6.5 ft | 10 ft | 12.2 µg/L |
| 6 | Dunes Lake | C | 4 ft | 1 ft | 21.2 µg/L |
| 7 | Forestville Flowage Lake | F | 1 ft | 5 ft | - |
| 8 | Forestville Millpond | F | 3 ft | 5 ft | 94.3 µg/L |
Source: EPA National Aquatic Resource Surveys, 2026.