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LakeQuality
B

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.

MetricValueGrade
Water Clarity (Secchi Depth)No data
Phosphorus27 µg/LB
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)52Eutrophic

High nutrients, frequent algae, reduced clarity

Water Quality Trend: Declining

Based on 7 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-0.594 m/yr7
Phosphorus Declining+0.3 µg/L/yr3

Location

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County Ranking

Ranked #52 of 55 lakes in Bayfield County

Nearby Lakes in Bayfield County

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.

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