Where is Old Mount Olive Reservoir?

Old Mount Olive Reservoir is a lake in Macoupin County, Illinois. Its water-quality measurements are published by Illinois EPA and shown on this page as reported.

How deep is Old Mount Olive Reservoir?

Old Mount Olive Reservoir has a maximum depth of 32 feet and an average depth of 11.2 feet. The lake covers 35 acres.

Old Mount Olive Reservoir

Macoupin County, Illinois35 acresView map Directions

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

Max depth

32 ft

Bathymetric survey

Area

35 acres

Surface area

Shoreline

3.2 mi

Measured length

Impaired · Mercury
32 ft max depth

See the measurements Directions Where to stay

Old Mount Olive Reservoir in Macoupin County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Maximum depth: 32 ft. Surface area: 35 acres.

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Old Mount Olive Reservoir is a 35-acre lake in Macoupin County, Illinois with a maximum depth of 32 feet (11-foot average).

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

What Old Mount Olive Reservoir is good for

From access and monitoring records, not editorial picks.

Deep water32 ft surveyed max depth

Swimming conditions

No reading

Not rated

Nutrient and algae readings are not a swimming clearance. Old Mount Olive Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, metals (other than mercury), nutrients (phosphorus, nitrogen), pesticides, turbidity. Check local advisories before you swim.

Whether Old Mount Olive Reservoir 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 Old Mount Olive Reservoir

These are the measurements Illinois EPA publishes for Old Mount Olive Reservoir, 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 Mount Olive Reservoir

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

Lake Details

Max depth

32 ft

Average depth

11.2 ft

Surface area

35 acres

Shoreline

3.2 mi

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Stays near Old Mount Olive Reservoir

Compare lakeside cabins, hotels, and vacation rentals near Old Mount Olive Reservoir in Macoupin 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.

Top-rated places to stay near Old Mount Olive Reservoir

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Fishing Old Mount Olive Reservoir

→ Old Mount Olive Reservoir fishing regulations (limits, seasons, special rules)

EPA Impairment Status

Old Mount Olive Reservoir is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

MercuryMetals (other than mercury)Nutrients (phosphorus, nitrogen)PesticidesTurbidity

Designated uses not supporting: Drinking water, Fish consumption, Other.

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

Source: EPA ATTAINS assessment unit IL_RJG · Official waterbody report

Nearby Lakes in Macoupin County

Mount Olive Lake1.5 miView →Staunton Reservoir3.5 miView →Old Gillespie Lake7.6 miView →New Gillespie Lake8.9 miView →Loveless LakeHypereutrophic10.6 miView →Smith Reservoir11.6 miView →

Frequently asked questions about Old Mount Olive Reservoir

Where is Old Mount Olive Reservoir?: Old Mount Olive Reservoir 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 Mount Olive Reservoir?: Old Mount Olive Reservoir in Macoupin County, Illinois has water-quality measurements published by Illinois EPA, shown here as reported. Maximum depth: 32 ft. Surface area: 35 acres.
Is Old Mount Olive Reservoir safe to swim in?: Nutrient and algae readings are not a swimming clearance. Old Mount Olive Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, metals (other than mercury), nutrients (phosphorus, nitrogen), pesticides, turbidity. Check local advisories before you swim.
How deep is Old Mount Olive Reservoir?: Old Mount Olive Reservoir has a maximum depth of 32 feet and an average depth of 11.2 feet. The lake covers 35 acres.