Old Gillespie Lake
Macoupin County, Illinois69 acresView mapDirections
No nutrient or algae sampling on record from Illinois EPA for this lake.
- Impaired · Mercury
- 23 ft max depth
Old Gillespie Lake in Macoupin County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Maximum depth: 23 ft. Surface area: 69 acres.
Old Gillespie Lake is a 69-acre lake in Macoupin County, Illinois with a maximum depth of 23 feet (10-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. Old Gillespie Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, nutrients (phosphorus, nitrogen), turbidity. Check local advisories before you swim.
Whether Old Gillespie 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 Old Gillespie Lake
These are the measurements Illinois EPA publishes for Old Gillespie 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 Old Gillespie Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
23 ft
Average depth
9.8 ft
Surface area
69 acres
Shoreline
4.8 mi
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Fishing Old Gillespie Lake
EPA Impairment Status
Old Gillespie 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: Fish consumption, Other.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit IL_SDT · Official waterbody report
Nearby Lakes in Macoupin County
Frequently asked questions about Old Gillespie Lake
Where is Old Gillespie Lake?
- Old Gillespie Lake is a lake in Macoupin County, Illinois. Its water-quality measurements are published by Illinois EPA and shown on this page as reported.
What is the water quality of Old Gillespie Lake?
- Old Gillespie Lake in Macoupin County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Maximum depth: 23 ft. Surface area: 69 acres.
Is Old Gillespie Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Old Gillespie Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, nutrients (phosphorus, nitrogen), turbidity. Check local advisories before you swim.
How deep is Old Gillespie Lake?
- Old Gillespie Lake has a maximum depth of 23 feet and an average depth of 9.8 feet. The lake covers 69 acres.
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Where this data comes from
Measurements for Old Gillespie 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