John Lake
Cook County, Minnesota182 acresView mapDirections
No nutrient or algae sampling on record from Minnesota PCA for this lake.
- Impaired · Mercury
- 20 ft max depth
John Lake in Cook County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Maximum depth: 20 ft. Surface area: 182 acres.
John Lake is a 182-acre lake in Cook County, Minnesota with a maximum depth of 20 feet.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder. Methodology: how these readings are compared.
Swimming conditions
No readingNot rated
Nutrient and algae readings are not a swimming clearance. John Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Whether John 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 John Lake
These are the measurements Minnesota PCA publishes for John Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data. TSI undefined.
Ask about John Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
20 ft
Surface area
182 acres
Shoreline
3.7 mi
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Fishing John Lake
EPA Impairment Status
John 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: Fish consumption.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN16-0035-00 · Official waterbody report
Nearby Lakes in Cook County
Frequently asked questions about John Lake
Where is John Lake?
- John Lake is a lake in Cook County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of John Lake?
- John Lake in Cook County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Maximum depth: 20 ft. Surface area: 182 acres.
Is John Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. John Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
How deep is John Lake?
- John Lake has a maximum depth of 20 feet. The lake covers 182 acres.
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Where this data comes from
Measurements for John Lake come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake details from Minnesota DNR LakeFinder