Lake Superior
Douglas County, WisconsinView mapDirections
Wisconsin DNR publishes the water-quality measurements for Lake Superior. Here is what has been measured.
- Limited data
Lake Superior in Douglas County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Phosphorus: 29 µg/L.
Lake Superior is a lake in Douglas County, Wisconsin. Water clarity is declining over recent sampling years. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2022-08-26. Methodology: how these readings are compared.
What Lake Superior is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Lake Superior 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 Lake Superior
These are the measurements Wisconsin DNR publishes for Lake Superior, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data. Phosphorus 29 µg/L. TSI 53.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | No reading How deep a black-and-white disk stays visible from the surface. Higher is clearer. | |
| Total phosphorus | 29µg/L | Measured, not scored 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. | 53 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Lake Superior
Answers come straight from the public measurements and survey records on this page.
Recreation & Access
- Amnicon RiverSemi-private
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Lake Superior
Compare lakeside cabins, hotels, and vacation rentals near Lake Superior in Douglas County, Wisconsin — 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 Lake Superior
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Fishing Lake Superior
Water Quality Trend: Stable
Based on 5 years of monitoring (2021–2025).
Water clarity
Worsening2 years
Phosphorus
Improving-1 µg/L/yr5 years
Nearby Lakes in Douglas County
Frequently asked questions about Lake Superior
Where is Lake Superior?
- Lake Superior is a lake in Douglas County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Lake Superior?
- Lake Superior in Douglas County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Phosphorus: 29 µg/L.
Is Lake Superior safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Are there boat ramps on Lake Superior?
- Lake Superior has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Amnicon River.
Can I fish at Lake Superior?
- Lake Superior has 1 documented boat landing in the USGS National Boat Ramps inventory. 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.
Explore Lake Superior across LakeQuality
2 documented falls within 6 mi, nearest Upper Falls (Amnicon Falls State Park)
Fish species and the cleanest lakes across Wisconsin
Fish species and best lakes in Douglas County
Species activity outlook by water temperature and season
Where to stay at Wisconsin's top lakes, each with its readings
Lakes in the St. Croix Watershed, ranked by water quality
Lakes in the Lake Superior Basin (MN+WI), ranked by water quality
Wisconsin's cleanest lakes, ranked on agency measurements
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Other Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
Where this data comes from
1 measurement from 1 monitoring station, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- USGS Wisconsin Water Science Center
USGS-WI1 sample · 2022
Analytical methods
- Phosphorus, wu,FIA EPA365.4 (WI)
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
Named boat-access points from the USGS National Boat Ramps inventory