South Twin Lake
Calhoun County, Iowa465 acresView mapDirections
No nutrient or algae sampling on record from Iowa DNR for this lake.
- Impaired · Algal growth
- 5 ft max depth
South Twin Lake in Calhoun County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Maximum depth: 5 ft. Surface area: 465 acres.
South Twin Lake is a 465-acre lake in Calhoun County, Iowa with a maximum depth of 5 feet.
Source: EPA Water Quality Portal sampling records, Iowa DNR. Methodology: how these readings are compared.
Swimming conditions
No readingNot rated
Nutrient and algae readings are not a swimming clearance. South Twin Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, turbidity. Check local advisories before you swim.
Whether South Twin Lake is safe to swim in today is a call for the Iowa Department of Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for South Twin Lake
These are the measurements Iowa DNR publishes for South Twin 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 South Twin Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
5 ft
Surface area
465 acres
Shoreline
4.1 mi
The depth above comes from a bathymetric survey of this lake, not from a regional estimate.
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Fishing South Twin Lake
EPA Impairment Status
South Twin 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: Aquatic life.
Source: EPA ATTAINS assessment unit IA 04-RAC-1168 · Official waterbody report
Nearby Lakes in Calhoun County
Frequently asked questions about South Twin Lake
Where is South Twin Lake?
- South Twin Lake is a lake in Calhoun County, Iowa. Its water-quality measurements are published by Iowa DNR and shown on this page as reported.
What is the water quality of South Twin Lake?
- South Twin Lake in Calhoun County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Maximum depth: 5 ft. Surface area: 465 acres.
Is South Twin Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. South Twin Lake is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, turbidity. Check local advisories before you swim.
How deep is South Twin Lake?
- South Twin Lake has a maximum depth of 5 feet. The lake covers 465 acres.
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Where this data comes from
Measurements for South Twin 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