Green County Lake Quality
Wisconsin, 1 lakes, average grade D (Poor)
Only 1 lakes in Green County carry an active grade. The county-level summary is therefore representative of those specific lakes, not necessarily of every water body in the county. 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.
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 Beckman Lake (D); the most-stressed is Beckman Lake (D).
Quick Answers for Green County
Planning a trip? Check special fishing regulations for Beckman Lake, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
DNR Reports (2)
Wisconsin DNR Fisheries Survey resources for lakes in Green County. browse all reports →
- 2025Decatur Lake spring shocking survey, 2025Spring Shocking Survey · WI DNR · 2025 (PDF)
- 2021Beckman Lake Fishery Summary, 2021Fisheries Survey · WI DNR · 2021 (PDF)
All Lakes in Green County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Beckman Lake | D | 6.6 ft | - | - |
Source: EPA National Aquatic Resource Surveys, 2026.