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LakeQuality
D

Unnamed Lake

Polk County, WisconsinLimited DataEutrophic

Unnamed Lake pulls a D on the LakeGrade rubric — phosphorus loading and limited clarity hold it below the Wisconsin average. 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. Unnamed Lake ranks 72 of 77 in Polk County — at the lower end of the locally monitored distribution.

Unnamed Lake has no invasive species recorded in Wisconsin state databases as of 2022, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Unnamed Lake, 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 2022-07-13. Grade methodology: LakeGrade methodology.

Swimming Safety

Swimming not recommended, poor water quality with high algae risk

Water Quality Grade: D, Poor

Murky, only visible to about 5.4 ft. Trophic State Index: 53.

MetricValueGrade
Water Clarity (Secchi Depth)5.4 ftD
PhosphorusNo data
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)53Eutrophic

High nutrients, frequent algae, reduced clarity

Water Quality Trend: Improving

Based on 3 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Improving+0.293 m/yr3
See year-by-year chart →

Location

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County Ranking

Ranked #72 of 77 lakes in Polk County

Cleaner Lakes Within 30 Miles

Unnamed Lake holds Grade D. 5 nearby lakes hold higher grades.

See full comparison →

Nearby Lakes in Polk County

Eutrophic Lakes in Wisconsin

Data Sources

Water quality data from the EPA Water Quality Portal

Grading methodology based on Metropolitan Council standards

Fish and recreation data from Wisconsin DNR Lakes

Most recent sample: 2022-07-13

Monitoring stations: 1