Monroe County Lake Quality
Wisconsin, 1 lake, average grade D (Nutrient-rich)
Monroe County has 1 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. The county-wide average grade is D — water quality issues are persistent across most of the monitored basins. 0 lakes fall into the F bracket outright.
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. Lake Tomah (D) is the cleanest in the county.
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Quick Answers for Monroe County
Planning a trip? Check special fishing regulations for Lake Tomah, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
DNR Reports (5)
Wisconsin DNR Fisheries Survey resources for lakes in Monroe County. browse all reports →
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- 2025Lake Tomah fish age and growth, 2025Fisheries Survey · WI DNR · 2025 (PDF)
- 2025Lake Tomah shocking and netting survey, 2025Netting Survey · WI DNR · 2025 (PDF)
- 2025Lake Wazeda netting survey, 2025Netting Survey · WI DNR · 2025 (PDF)
- 2019Perch Lake Fisheries Survey, 2019Fisheries Survey · WI DNR · 2019 (PDF)
- —Lake Tomah comprehensive survey, 2017-2022Comprehensive Survey · WI DNR (PDF)
All Lakes in Monroe County
1 lake1 graded lake
| # | Lake | Grade | Clarity | Phosphorus | Algae | Trophic | Max Depth | Access |
|---|---|---|---|---|---|---|---|---|
| 1 | DLake TomahMonroe | D | No recent samples | 140 µg/L | No recent samples | No recent samples | 19 ft | ✓ Public |
Lake Match
Which lake suits how you actually use one?
Six questions — swimming, fishing, quiet, cabins, drive time — and a shortlist of graded lakes that fit, with the water quality behind each one.
Other Counties in Wisconsin
See how Monroe County stacks up in the national county water-quality rankings, or browse the full directory of graded lakes across all 39 states and 2 Canadian provinces.
Source: EPA National Aquatic Resource Surveys, 2026.