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LakeQuality

Unnamed Lake

Watonwan County, MinnesotaView mapDirections

Minnesota PCA publishes the water-quality measurements for Unnamed Lake. Here is what has been measured.

Clarity
1 ft
Murkier than most
Secchi · sampled 2022
Phosphorus
275 µg/L
More phosphorus than most
Measured by Minnesota PCA
Chlorophyll-a
142 µg/L
More algae than most
Measured by Minnesota PCA
Max depth
~54 ft est.
GLOBathy model
  • 54 ft max depth
  • Public access
  • Limited data

Unnamed Lake in Watonwan County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 1 ft visibility. Phosphorus: 275 µg/L. Chlorophyll-a (algae): 142 µg/L.

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Unnamed Lake is a lake in Watonwan County, Minnesota with an estimated average depth of about 54 feet. Limited fish-species data available. Public access is available.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2022-06-22. Methodology: how these readings are compared.

Swimming conditions

No reading

Limited data

Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.

Whether Unnamed 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.

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Water quality measurements for Unnamed Lake

These are the measurements Minnesota PCA publishes for Unnamed 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 1 ft of visibility. Phosphorus 275 µg/L. Chlorophyll-a 142 µg/L. TSI 81.

Water quality readings
MeasureReadingWhere it sits
Water clarity (Secchi depth)1ftMeasured, not scored

How deep a black-and-white disk stays visible from the surface. Higher is clearer.

Total phosphorus275µg/LMeasured, not scored

The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential.

Chlorophyll-a (algae)142µg/LMeasured, not scored

The green pigment in algae — a direct measure of how much algae is in the water.

Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a.81Hypereutrophic
OligotrophicMesotrophicEutrophicHypereutrophic

Very high nutrients, dense algae, poor clarity

Ask about Unnamed Lake

Answers come straight from the public measurements and survey records on this page.

Lake Details

Max depth

~54 ft est.

Public access

Yes

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 Unnamed Lake.

Lake Size & Watershed

Watershed (drainage) area

1 sq mi

HydroLAKES / HydroSHEDS

Surface area

67 acres

HydroLAKES / HydroSHEDS

Shoreline

2.5 mi

HydroLAKES / HydroSHEDS

Elevation

1,240 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.

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Stays near Unnamed Lake

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Fishing Unnamed Lake

Regulated Pollution Sources Nearby

2 EPA-permitted facilities operate within about 5 miles of Unnamed Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.

  • Butterfield Wwtp
    Butterfield · 4 mi away · NPDES MN0022977
    Recent violation
  • Menken Farms
    Butterfield · 1.8 mi away · NPDES MN0071251

Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.

Nearby Lakes in Watonwan County

Frequently asked questions about Unnamed Lake

Where is Unnamed Lake?

Unnamed Lake is a lake in Watonwan County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.

What is the water quality of Unnamed Lake?

Unnamed Lake in Watonwan County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 1 ft visibility. Phosphorus: 275 µg/L. Chlorophyll-a (algae): 142 µg/L.

Measurements on this page ↑

Is Unnamed Lake safe to swim in?

Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.

Swimming on this page ↑

How deep is Unnamed Lake?

No published bathymetric survey covers Unnamed Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 54 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 Unnamed Lake?

Public access to Unnamed Lake is listed as yes on the lake record. 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.

State Parks Near Unnamed Lake

Hypereutrophic Lakes in Minnesota

Where this data comes from

4 measurements from 1 monitoring station, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Minnesota Pollution Control Agency - Ambient Surface WaterMNPCA4 samples · 2022

Analytical methods

  • Field measurement/observation, generic method
  • Phosphorus by Colorimetry
  • 10200 H ~ Chlorophyll a-b-c Determination
  • 2120 B ~ Color in Water by Visual Comparison
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

Regulated discharger data from EPA ECHO (ICIS-NPDES)

Lake size & watershed from HydroLAKES (HydroSHEDS)

Lake details from Minnesota DNR LakeFinder