Lake Eau Galle
Dunn County, WisconsinEutrophic
The LakeGrade rubric puts Lake Eau Galle at a C: clarity at 8.2 ft, 69 µg/L of phosphorus, and a TSI of 56 signal an intermediate trophic state. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.
Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake's surface area is not consistently recorded across state datasets — physical context remains partial. Lake Eau Galle ranks 3 of 3 in Dunn County — at the lower end of the locally monitored distribution.
No invasive species are currently listed at Lake Eau Galle — the lake remains off the Wisconsin infested-waters roster. The state fisheries records do not list documented species for Lake Eau Galle, which usually reflects a lack of formal fisheries survey work rather than an empty lake. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-09-13. Grade methodology: LakeGrade methodology.
Swimming Safety
Generally safe for swimming, moderate water quality
Water Quality Grade: C, Fair
Moderate clarity, visible to about 8.2 ft. Phosphorus level: 68.6 µg/L. Trophic State Index: 56.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 8.2 ft | C |
| Phosphorus | 68.6 µg/L | D |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 56 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Water Quality Trend: ↓ Declining
Based on 3 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.114 m/yr | 3 |
| Phosphorus | ↓ Declining | +2 µg/L/yr | 2 |
Location
County Ranking
Ranked #3 of 3 lakes in Dunn County
Cleaner Lakes Within 30 Miles
Lake Eau Galle holds Grade C. 2 nearby lakes hold higher grades.
- BNugget LakePierce County · 10 mi · Higher grade (C → B)
- CLake MenominDunn County · 14 mi · Higher overall water quality score
Nearby Lakes in Dunn County
More Wisconsin Lake Rankings
Other Grade C Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
DNR Reports & Resources
Wisconsin DNR Fisheries scientists publish multi-year survey reports for Lake Eau Galle covering fish populations, stocking, water quality, and management. 1 report on file.
- 2023Lake Eau Galle spring survey, 2023Fisheries Survey · WI DNR · 2023 (PDF)
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2025-09-13
Monitoring stations: 2