Portage County Lake Quality
Wisconsin, 28 lakes, average grade B (Good)
Portage County's 28 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.
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. Ebert Lake (A) is the cleanest in the county.
Quick Answers for Portage County
Planning a trip? Check special fishing regulations for Ebert Lake, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
DNR Reports (4)
Wisconsin DNR Fisheries Survey resources for lakes in Portage County. browse all reports →
- 2025Thomas Lake spring shocking, 2025Spring Shocking Survey · WI DNR · 2025 (PDF)
- 2024Sunset Lake spring shocking, 2024Spring Shocking Survey · WI DNR · 2024 (PDF)
- 2023Stevens Point Flowage comprehensive survey, 2023Comprehensive Survey · WI DNR · 2023 (PDF)
- 2022Collins Lake spring shocking, 2022Spring Shocking Survey · WI DNR · 2022 (PDF)
All Lakes in Portage County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Ebert Lake | A | 21 ft | 30 ft | - |
| 2 | Rinehart Lake | A | 19 ft | 27 ft | 13.8 µg/L |
| 3 | Unnamed Lake | A | - | - | 6.5 µg/L |
| 4 | Fountain Lake | A | 22 ft | 23 ft | - |
| 5 | Thomas Lake | A | 15 ft | 28 ft | - |
| 6 | Lake Helen | A | - | 20 ft | 16.1 µg/L |
| 7 | Lake Emily | A | 11 ft | 35 ft | 16.9 µg/L |
| 8 | Sunset Lake | A | 13.3 ft | 55 ft | 12 µg/L |
| 9 | Onland Lake | A | 10.5 ft | 28 ft | 11.1 µg/L |
| 10 | Pickerel Lake | B | 10 ft | 12 ft | - |
| 11 | Bear Lake | B | 13 ft | 28 ft | - |
| 12 | Glisezinski Lake | B | 9 ft | 11 ft | 16.4 µg/L |
| 13 | Lake Helen | B | 7.3 ft | 20 ft | 19.3 µg/L |
| 14 | Lake Lime | B | 10.5 ft | 29 ft | - |
| 15 | Springville Pond | B | 9 ft | 10 ft | 18.8 µg/L |
| 16 | Joanis Lake | B | - | - | 23 µg/L |
| 17 | Spring Lake | B | 8.4 ft | 42 ft | 29.9 µg/L |
| 18 | Tree Lake | B | 7.3 ft | 33 ft | 20.1 µg/L |
| 19 | Wolf Lake | C | 8.5 ft | 17 ft | - |
| 20 | Collins Lake | C | 6.5 ft | 56 ft | 20.6 µg/L |
| 21 | Adams Lake | C | 7.3 ft | 44 ft | - |
| 22 | Amherst Millpond | C | - | 7 ft | 31.3 µg/L |
| 23 | Mcdill Pond | C | 5 ft | 19 ft | 34.2 µg/L |
| 24 | Jordan Pond | C | 4 ft | 7 ft | 35.6 µg/L |
| 25 | South Twin Lake | D | 5 ft | 9 ft | - |
| 26 | Lake Ell Lake | D | 3.5 ft | 20 ft | - |
| 27 | Lake Pacawa | D | 4.5 ft | 12 ft | - |
| 28 | Culvert on Lake Helen | D | - | - | 87.1 µg/L |
Source: EPA National Aquatic Resource Surveys, 2026.