Skip to main content
LakeQuality
F

Wilhelm Lake

Wright County, MinnesotaHypereutrophic

Wilhelm Lake grades an F: water clarity, phosphorus, and chlorophyll-a all rate poorly, placing it among the most stressed lakes monitored in Minnesota. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

Hypereutrophic conditions mean the lake is operating at the upper end of the productivity scale, with all the bloom risk that implies. 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. Within the 64 graded lakes of Wright County, Wilhelm Lake sits at rank 61, near the bottom of the county list.

No invasive species are currently listed at Wilhelm Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Wilhelm Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. The lake lacks a documented public access point, so visitor use is limited. 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, Minnesota DNR LakeFinder, last sampled 2024-09-15. Grade methodology: LakeGrade methodology.

Swimming Safety

Avoid swimming, very poor water quality, potential algae toxins

Water Quality Grade: F, Very Poor

Very murky, less than 2 ft of visibility. Phosphorus level: 131 µg/L. Trophic State Index: 71.

MetricValueGrade
Water Clarity (Secchi Depth)2 ftF
Phosphorus131 µg/LF
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)71Hypereutrophic

Very high nutrients, dense algae, poor clarity

Water Quality Trend: Improving

Based on 5 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Improving+0.032 m/yr5
Phosphorus Improving-49.85 µg/L/yr5

Location

Loading map…

County Ranking

Ranked #61 of 64 lakes in Wright County

Nearby Lakes in Wright County

State Parks Near Wilhelm Lake

Hypereutrophic Lakes in Minnesota

Data Sources

Water quality data from the EPA Water Quality Portal

Grading methodology based on Metropolitan Council standards

Most recent sample: 2024-09-15

Monitoring stations: 1