Joanis Lake
Portage County, Wisconsin23 acresView mapDirections
No nutrient or algae sampling on record from Wisconsin DNR for this lake.
- Public access
- Limited data
Joanis Lake in Portage County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Surface area: 23 acres.
Joanis Lake is a 23-acre lake in Portage County, Wisconsin. Limited fish-species data available. Public access is available.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-04-14. 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 Joanis 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 Joanis Lake
These are the measurements Wisconsin DNR publishes for Joanis 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.
Ask about Joanis Lake
Answers come straight from the public measurements and survey records on this page.
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. 1 station on file (most recent sample 2025).
Lake Details
Surface area
23 acres
Public access
Yes
Listed by Wisconsin DNR
No bathymetric survey has been published for Joanis Lake, so its depth is not documented here.
Stays via Stay22
Stays near Joanis Lake
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Fishing Joanis Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
Nearby Lakes in Portage County
Frequently asked questions about Joanis Lake
Where is Joanis Lake?
- Joanis 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 Joanis Lake?
- Joanis Lake in Portage County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Surface area: 23 acres.
Is Joanis Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Can I fish at Joanis Lake?
- Public access to Joanis Lake is listed as yes on the lake record. Seasons, size and bag limits, and whether you need a license are set by Wisconsin's fish and wildlife agency, so check its current regulations before you go.
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Where this data comes from
12 measurements from 1 monitoring station, 2023–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX12 samples · 2023–2026
Analytical methods
- Total Phosphorus After Block Digestion
- 2130 B ~ Nephelometric Method
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
Fish and recreation data from Wisconsin DNR Lakes