Jefferson County Lake Quality
Wisconsin, 15 lakes, measured by Wisconsin DNR
There are 15 monitored lakes in Jefferson County. The mix is varied enough that the county-level average tells you the broad strokes, not the choose-this-cabin specifics. 7 of those lakes carry recent nutrient and algae readings. The county-level summary describes that subset, not every water body listed. For Jefferson County the spread behind the average matters more than the average itself: a few nutrient-rich lakes among many clear ones produce the same figure as the inverse.
The county's lakes lean shallow, which makes the readings sensitive to wind, sediment-resuspension, and any nutrient inputs from the watershed. The cleanest measured lake is Rock Lake.
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Quick Answers for Jefferson County
Planning a trip? Check special fishing regulations for Rock Lake, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
Fishing in Jefferson County
DNR Reports (4)
Wisconsin DNR Fisheries Survey resources for lakes in Jefferson County. browse all reports →
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- 2025Lower Spring Lake spring shocking survey, 2025Spring Shocking Survey · WI DNR · 2025 (PDF)
- 2023Lake Ripley comprehensive survey, 2023Comprehensive Survey · WI DNR · 2023 (PDF)
- 2023Lower Spring Lake Spring summary report, 2023Fisheries Survey · WI DNR · 2023 (PDF)
- 2022Rock Lake comprehensive survey, 2022Comprehensive Survey · WI DNR · 2022 (PDF)
All Lakes in Jefferson County
15 lakes · 7 ranked on readings, 8 without enough sampling7 lakes ranked on readings · 8 without enough sampling, hidden
| # | Lake | Clarity | Phosphorus | Algae | Trophic | Max Depth | Access |
|---|---|---|---|---|---|---|---|
| 1 | Rock LakeJefferson | 12 ft | 18.1 µg/L | No recent samples | No recent samples | 60 ft | ✓ Public |
| 2 | Red Cedar LakeJefferson | 4 ft | 23.4 µg/L | No recent samples | No recent samples | 6 ft | ✓ Public |
| 3 | Lake RipleyJefferson | 9 ft | 21.8 µg/L | No recent samples | No recent samples | 44 ft | ✓ Public |
| 4 | Blue Spring LakeJefferson | 6.2 ft | 24.7 µg/L | No recent samples | No recent samples | 27 ft | ✓ Public |
| 5 | Lower Spring LakeJefferson | 4 ft | 44.1 µg/L | No recent samples | No recent samples | No recent samples | ✓ Public |
| 6 | Mud LakeJefferson | 2.3 ft | 63.6 µg/L | No recent samples | No recent samples | 22 ft | ✓ Public |
| 7 | Lake KoshkonongJefferson | 1.7 ft | 287 µg/L | No recent samples | No recent samples | 7 ft | ✓ Public |
| Hope LakeJefferson | 8 ft | No recent samples | No recent samples | No recent samples | 24 ft | Not recorded | |
| Hahns LakeJefferson | No recent samples | No recent samples | No recent samples | No recent samples | 10 ft | Not recorded | |
| Goose LakeJefferson | No recent samples | No recent samples | No recent samples | No recent samples | No recent samples | Not recorded | |
| Rome PondJefferson | No recent samples | No recent samples | No recent samples | No recent samples | 7 ft | Not recorded | |
| Cushman PondJefferson | No recent samples | No recent samples | No recent samples | No recent samples | No recent samples | Not recorded | |
| Green Isle LakeJefferson | No recent samples | No recent samples | No recent samples | No recent samples | 15 ft | Not recorded | |
| Bean LakeJefferson | No recent samples | No recent samples | No recent samples | No recent samples | 6 ft | Not recorded | |
| Mud LakeJefferson | No recent samples | No recent samples | No recent samples | No recent samples | No recent samples | Not recorded |
NR = no nutrient or algae reading on record. The measurements are published as the authority reports them. Where the data comes from.
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Source: the Wisconsin Department of Natural Resources. See data sources.