Green Lake County Lake Quality
Wisconsin, 13 lakes, average grade C (Fair)
Green Lake County has 13 graded lakes — a thin enough sample that one or two stressed lakes can move the county average noticeably. Use the per-lake pages below for what actually matters. Green Lake County averages to a C. The distribution behind that average matters more than the letter: a few stressed lakes versus many decent ones can produce the same average as the inverse.
A meaningful share of Green Lake's lakes break 50 feet of depth, which matters because deep lakes hold cooler water all summer and resist the resuspended-sediment problems that plague shallow basins. The county's best-graded lake is Big Twin Lake (A).
Quick Answers for Green Lake County
Planning a trip? Check special fishing regulations for Big Twin Lake, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
DNR Reports (6)
Wisconsin DNR Fisheries Survey resources for lakes in Green Lake County. browse all reports →
- 2024Little Green Lake comprehensive survey, 2024Comprehensive Survey · WI DNR · 2024 (PDF)
- 2023Big Green Lake creel survey, 2023Creel Survey · WI DNR · 2023 (PDF)
- 2023Big Twin Lake spring shocking survey, 2023Spring Shocking Survey · WI DNR · 2023 (PDF)
- 2023Lake Puckaway summary survey, 2023Fisheries Survey · WI DNR · 2023 (PDF)
- 2022Big Green Lake comprehensive survey, 2022Comprehensive Survey · WI DNR · 2022 (PDF)
- 2018Spring Lake comprehensive survey, 2018Comprehensive Survey · WI DNR · 2018 (PDF)
All Lakes in Green Lake County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Big Twin Lake | A | 23 ft | - | - |
| 2 | Green Lake | B | 13.3 ft | 236 ft | 23 µg/L |
| 3 | Green Lake | B | 13 ft | 236 ft | - |
| 4 | Green Lake | B | - | - | 20.6 µg/L |
| 5 | Green Lake | B | 14.1 ft | 236 ft | 32 µg/L |
| 6 | Lake Puckaway | B | 14.3 ft | - | 52.1 µg/L |
| 7 | Green Lake East Basin | B | 11.8 ft | 236 ft | 43 µg/L |
| 8 | Green Lake | C | 13.1 ft | 236 ft | 66.5 µg/L |
| 9 | City Millpond | C | - | 236 ft | 38.4 µg/L |
| 10 | Little Green Lake | D | 8.9 ft | 28 ft | 91.7 µg/L |
| 11 | Little Twin Lake | D | 4.9 ft | - | - |
| 12 | Silver Creek Estuary Lake | F | - | 236 ft | 122 µg/L |
| 13 | County K Marsh Lake | F | - | - | 149.5 µg/L |
Source: EPA National Aquatic Resource Surveys, 2026.