Wilhelm Lake
Wright County, MinnesotaView mapDirections
Minnesota PCA publishes the water-quality measurements for Wilhelm Lake. Here is what has been measured.
- Hypereutrophic
- Impaired · Nutrients (phosphorus, nitrogen)
- 36 ft max depth
Wilhelm Lake in Wright County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 2 ft visibility. Phosphorus: 124 µg/L. Chlorophyll-a (algae): 60.5 µg/L.
Wilhelm Lake is a highly nutrient-loaded hypereutrophic lake in Wright County, Minnesota with an estimated average depth of about 36 feet. Overall water quality is improving over recent sampling years. Limited fish-species data available. No public access — the lake is private or restricted. Compared to the 50 other monitored lakes in Wright County, Wilhelm Lake ranks #48 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-17. Methodology: how these readings are compared.
Swimming conditions
Readings onlyRecreation use not supported
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Wilhelm Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Wilhelm Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Wilhelm Lake
These are the measurements Minnesota PCA publishes for Wilhelm Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 2 ft of visibility. Phosphorus 124 µg/L. Chlorophyll-a 60.5 µg/L. TSI 71.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 2ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 124µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 60.5µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 71 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Wilhelm Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
~36 ft est.
Public access
No
Listed by Minnesota PCA
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Minnesota has not published bathymetry for Wilhelm Lake.
Lake Size & Watershed
Watershed (drainage) area
4 sq mi
HydroLAKES / HydroSHEDS
Surface area
86 acres
HydroLAKES / HydroSHEDS
Shoreline
3 mi
HydroLAKES / HydroSHEDS
Elevation
938 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Stays via Stay22
Stays near Wilhelm Lake
Compare lakeside cabins, hotels, and vacation rentals near Wilhelm Lake in Wright County, Minnesota — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Wilhelm Lake are listed below.
Top-rated places to stay near Wilhelm Lake
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Fishing Wilhelm Lake
Water Quality Trend: Improving
Based on 6 years of monitoring (2020–2025).
Water clarity
Improving6 years
Phosphorus
Improving-36.66 µg/L/yr6 years
Chlorophyll-a
Worsening+4.76 µg/L/yr6 years
EPA Impairment Status
Wilhelm Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN86-0020-00 · Official waterbody report
Nearby Lakes in Wright County
Frequently asked questions about Wilhelm Lake
Where is Wilhelm Lake?
- Wilhelm Lake is a lake in Wright County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Wilhelm Lake?
- Wilhelm Lake in Wright County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 2 ft visibility. Phosphorus: 124 µg/L. Chlorophyll-a (algae): 60.5 µg/L.
Is Wilhelm Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Wilhelm Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
How deep is Wilhelm Lake?
- No published bathymetric survey covers Wilhelm Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 36 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Can I fish at Wilhelm Lake?
- Public access to Wilhelm Lake is listed as no on the lake record, so confirm before you make the trip. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.
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Where this data comes from
69 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA69 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder