Where is Grand Marais Lake?

Grand Marais Lake is a lake in St. Clair County, Illinois. Its water-quality measurements are published by Illinois EPA and shown on this page as reported.

Grand Marais Lake

St. Clair County, Illinois83 acresView map Directions

No nutrient or algae sampling on record from Illinois EPA for this lake.

Area

83 acres

Surface area

Shoreline

2.3 mi

Measured length

Impaired · Algal growth

See the measurements Directions Where to stay

Grand Marais Lake in St. Clair County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Surface area: 83 acres.

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Grand Marais Lake is a 83-acre lake in St. Clair County, Illinois.

Source: EPA Water Quality Portal sampling records, Illinois EPA. Methodology: how these readings are compared.

Swimming conditions

No reading

Not rated

Nutrient and algae readings are not a swimming clearance. Grand Marais Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, nuisance exotic species, nutrients (phosphorus, nitrogen), oxygen depletion (low DO), pCBs, turbidity. Check local advisories before you swim.

Whether Grand Marais Lake is safe to swim in today is a call for the Illinois Environmental Protection Agency and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

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Water quality measurements for Grand Marais Lake

These are the measurements Illinois EPA publishes for Grand Marais 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.

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

Lake Details

Surface area

83 acres

Shoreline

2.3 mi

No bathymetric survey has been published for Grand Marais Lake, so its depth is not documented here.

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Stays near Grand Marais Lake

Compare lakeside cabins, hotels, and vacation rentals near Grand Marais Lake in St. Clair County, Illinois — 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.

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Fishing Grand Marais Lake

→ Grand Marais Lake fishing regulations (limits, seasons, special rules)

EPA Impairment Status

Grand Marais Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

Algal growthNuisance exotic speciesNutrients (phosphorus, nitrogen)Oxygen depletion (low DO)PCBsTurbidity

Designated uses not supporting: Aquatic life, Fish consumption, Other.

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit IL_RJM · Official waterbody report

Nearby Lakes in St. Clair County

Spring Lake3.7 miView →River King Mine Lake—View →Biebell Lake—View →Brush Lake—View →Slm Side Channel Lake0.8 ft clear · Hypereutrophic—View →Round Pond—View →

Frequently asked questions about Grand Marais Lake

Where is Grand Marais Lake?: Grand Marais Lake is a lake in St. Clair County, Illinois. Its water-quality measurements are published by Illinois EPA and shown on this page as reported.
What is the water quality of Grand Marais Lake?: Grand Marais Lake in St. Clair County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Surface area: 83 acres.
Is Grand Marais Lake safe to swim in?: Nutrient and algae readings are not a swimming clearance. Grand Marais Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, nuisance exotic species, nutrients (phosphorus, nitrogen), oxygen depletion (low DO), pCBs, turbidity. Check local advisories before you swim.