Fourth Lake
Lake County, Illinois297 acresView mapDirections
No nutrient or algae sampling on record from Illinois EPA for this lake.
- Impaired · Noxious aquatic plants
- 6 ft max depth
Fourth Lake in Lake County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Maximum depth: 5.5 ft. Surface area: 297 acres.
Fourth Lake is a 297-acre lake in Lake County, Illinois with a maximum depth of 6 feet (3-foot average).
Source: EPA Water Quality Portal sampling records, Illinois EPA. Methodology: how these readings are compared.
Swimming conditions
No readingNot rated
Nutrient and algae readings are not a swimming clearance. Fourth Lake is listed impaired under Clean Water Act §303(d) (IR 5) for noxious aquatic plants, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Fourth 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.
Water quality measurements for Fourth Lake
These are the measurements Illinois EPA publishes for Fourth 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 Fourth Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
5.5 ft
Average depth
2.7 ft
Surface area
297 acres
Shoreline
5.5 mi
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Fishing Fourth Lake
EPA Impairment Status
Fourth Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Other.
Source: EPA ATTAINS assessment unit IL_RGZC · Official waterbody report
Nearby Lakes in Lake County
Frequently asked questions about Fourth Lake
Where is Fourth Lake?
- Fourth Lake is a lake in Lake County, Illinois. Its water-quality measurements are published by Illinois EPA and shown on this page as reported.
What is the water quality of Fourth Lake?
- Fourth Lake in Lake County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Maximum depth: 5.5 ft. Surface area: 297 acres.
Is Fourth Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Fourth Lake is listed impaired under Clean Water Act §303(d) (IR 5) for noxious aquatic plants, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
How deep is Fourth Lake?
- Fourth Lake has a maximum depth of 5.5 feet and an average depth of 2.7 feet. The lake covers 297 acres.
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Where this data comes from
Measurements for Fourth 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