Manitowoc County Lake Quality
Wisconsin, 18 lakes, average grade B (Good)
Manitowoc County's 18 graded lakes fall in the moderate-density bracket for Wisconsin. The county-level average smooths over real differences — a single agricultural watershed near the southwest corner can pull the average down even if the rest of the county runs clean. The county-wide average lands at B — solid water quality with most lakes carrying clear summer transparency and low-to-moderate phosphorus.
The county's lakes lean shallow, which makes the grades sensitive to wind, sediment-resuspension, and any nutrient inputs from the watershed. The cleanest lake on the books is Spring Lake (A); the most-stressed is Long Lake (D).
Quick Answers for Manitowoc County
Planning a trip? Check special fishing regulations for Spring Lake, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
DNR Reports (16)
Wisconsin DNR Fisheries Survey resources for lakes in Manitowoc County. Showing 12 most recent — browse all reports →
- 2024Pigeon Lake comprehensive summary survey, 2024Comprehensive Survey · WI DNR · 2024 (PDF)
- 2023Rockville Flowage spring shocking survey, 2023Spring Shocking Survey · WI DNR · 2023 (PDF)
- 2023Silver Lake comprehensive summary survey, 2023Comprehensive Survey · WI DNR · 2023 (PDF)
- 2022Cedar Lake comprehensive survey, 2022Comprehensive Survey · WI DNR · 2022 (PDF)
- 2018Shoe Lake electrofishing survey, 2018Fisheries Survey · WI DNR · 2018 (PDF)
- 2018Wilke Lake comprehensive survey 2018Comprehensive Survey · WI DNR · 2018 (PDF)
- 2017Bullhead Lake comprehensive survey 2017Comprehensive Survey · WI DNR · 2017 (PDF)
- 2017Long Lake comprehensive survey 2017Comprehensive Survey · WI DNR · 2017 (PDF)
- 2016Cedar Lake comprehensive survey 2016Comprehensive Survey · WI DNR · 2016 (PDF)
- 2015Carstens Lake spring survey 2015Fisheries Survey · WI DNR · 2015 (PDF)
- 2015East Twin River trout survey 2015Trout Survey · WI DNR · 2015 (PDF)
- 2015Point Creek bass survey 2015Fisheries Survey · WI DNR · 2015 (PDF)
All Lakes in Manitowoc County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Spring Lake | A | 26.2 ft | 23 ft | 19.6 µg/L |
| 2 | Cedar Lake | A | 34.5 ft | - | 17.3 µg/L |
| 3 | Tuma Lake | A | 32.8 ft | 36 ft | 19 µg/L |
| 4 | Pigeon Lake | A | 29.6 ft | 62 ft | 15.4 µg/L |
| 5 | Mi32 Lake | A | 49.2 ft | - | - |
| 6 | Wilke Lake | A | 23 ft | 21 ft | 16.5 µg/L |
| 7 | English Lake | A | 24.6 ft | - | 26.7 µg/L |
| 8 | Shoe Lake | A | 23 ft | 34 ft | 26.6 µg/L |
| 9 | Kasbaum Lake | A | 32 ft | 68 ft | 22.2 µg/L |
| 10 | Horseshoe Lake | B | 24.6 ft | 54 ft | 36.2 µg/L |
| 11 | Hartlaub Lake | B | 16.4 ft | 60 ft | 35.8 µg/L |
| 12 | Little Pigeon Lake | B | - | 14.5 ft | 20 µg/L |
| 13 | Harpt Lake | B | 12.3 ft | 54 ft | 44.2 µg/L |
| 14 | Gass Lake | B | 19.7 ft | 24 ft | 62.9 µg/L |
| 15 | Carstens Lake | C | 17.2 ft | - | 92.6 µg/L |
| 16 | Bullhead Lake | C | 13.1 ft | 40 ft | 68.4 µg/L |
| 17 | Weyers Lake | C | 21.3 ft | 32 ft | 92.3 µg/L |
| 18 | Long Lake | D | 5.2 ft | 38 ft | 90.4 µg/L |
Source: EPA National Aquatic Resource Surveys, 2026.