Wiley Lake
Bayfield County, WisconsinLimited DataEutrophic
On the LakeGrade scale Wiley Lake grades a B, with clarity readings still being added and 27 µg/L of phosphorus placing it above the Wisconsin median. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.
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. Wiley Lake ranks 52 of 55 in Bayfield County — at the lower end of the locally monitored distribution.
No invasive species are currently listed at Wiley Lake — the lake remains off the Wisconsin infested-waters roster. The state fisheries records do not list documented species for Wiley Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-11-15. Grade methodology: LakeGrade methodology.
Swimming Safety
Good for swimming, clear water with low algae levels
Water Quality Grade: B, Good
No clarity data. Phosphorus level: 27 µg/L. Trophic State Index: 52.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No data | |
| Phosphorus | 27 µg/L | B |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 52 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Water Quality Trend: ↓ Declining
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.594 m/yr | 7 |
| Phosphorus | ↓ Declining | +0.3 µg/L/yr | 3 |
Location
County Ranking
Ranked #52 of 55 lakes in Bayfield County
Nearby Lakes in Bayfield County
More Wisconsin Lake Rankings
Other Grade B Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
DNR Reports & Resources
Wisconsin DNR Fisheries scientists publish multi-year survey reports for Wiley Lake covering fish populations, stocking, water quality, and management. 1 report on file.
- 2024Cable Wiley lakes spring shocking survey, 2024Spring Shocking Survey · WI DNR · 2024 (PDF)
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2025-11-15
Monitoring stations: 1