South Twin Lake
Portage County, Wisconsin54 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for South Twin Lake. Here is what has been measured.
- 9 ft max depth
- Limited data
South Twin Lake in Portage County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 5 ft visibility. Maximum depth: 9 ft. Surface area: 54 acres.
Wisconsin DNR lists Panfish as present on South Twin Lake. DNR survey details →
South Twin Lake is a 54-acre lake in Portage County, Wisconsin with a maximum depth of 9 feet. The lake supports 1 documented fish species including Panfish.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2021-09-22. Methodology: how these readings are compared.
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether South Twin Lake is safe to swim in today is a call for the Wisconsin 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 Wisconsin 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.
Murky, only visible to about 5 ft. TSI 54.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 54 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about South Twin Lake
Answers come straight from the public measurements and survey records on this page.
Wisconsin DNR lists Panfish as present on South Twin Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows South Twin Lake’s water-quality measurements separately. Catch rate is not a swim clearance and is not a weekly bite report.
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. 1 station on file (most recent sample 2021).
Fish Species (DNR-rated)
Lake Details
Max depth
9 ft
Surface area
54 acres
Lake Size & Watershed
Watershed (drainage) area
0 sq mi
HydroLAKES / HydroSHEDS
Shoreline
1.3 mi
HydroLAKES / HydroSHEDS
Elevation
1,188 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
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Fish Species
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Fishing South Twin Lake
Nearby Lakes in Portage County
Frequently asked questions about South Twin Lake
Where is South Twin Lake?
- South Twin Lake is a lake in Portage County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of South Twin Lake?
- South Twin Lake in Portage County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 5 ft visibility. Maximum depth: 9 ft. Surface area: 54 acres.
Is South Twin Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is South Twin Lake?
- South Twin Lake has a maximum depth of 9 feet. The lake covers 54 acres.
What fish are in South Twin Lake?
- Fish species found in South Twin Lake include Panfish. South Twin Lake is located in Portage County, Wisconsin.
What did the DNR fisheries survey find at South Twin Lake?
- Wisconsin DNR lists Panfish as present on South Twin Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows South Twin Lake’s water-quality measurements separately. Catch rate is not a swim clearance and is not a weekly bite report.
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Where this data comes from
1 measurement from 1 monitoring station, 2021. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX1 sample · 2021
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Lake size & watershed from HydroLAKES (HydroSHEDS)
Fish and recreation data from Wisconsin DNR Lakes