Blue Lake
Oneida County, Wisconsin441 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Blue Lake. Here is what has been measured.
- Oligotrophic
- 49 ft max depth
Blue Lake in Oneida County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 23 ft visibility. Phosphorus: 10.7 µg/L. Maximum depth: 49 ft. Surface area: 441 acres.
Wisconsin DNR lists Panfish as common on Blue Lake. DNR survey details →
Blue Lake is a 441-acre cold, clear oligotrophic lake in Oneida County, Wisconsin with a maximum depth of 49 feet. Overall water quality is declining over recent sampling years. The lake supports 4 documented fish species including Panfish, Largemouth Bass, and Smallmouth Bass. Compared to the 66 other monitored lakes in Oneida County, Blue Lake ranks #28 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-26. Methodology: how these readings are compared.
What Blue Lake is good for
From access and monitoring records, not editorial picks.
- Clear water23 ft of visibility
- Fishing4 species recorded
- Deep water49 ft surveyed max depth
Swimming conditions
Readings onlyLow algae
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Blue 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 Blue Lake
These are the measurements Wisconsin DNR publishes for Blue Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Crystal clear, you can see 23 ft down. Phosphorus 10.7 µg/L. TSI 35.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 23ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 10.7µg/L | Good GoodFairPoor |
| 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. | 35 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Blue Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Blue Lake typically sits around 72°F at the surface in August. Summer average is about 73°F. Usually warmest in Jul (about 74°F) and coldest in Apr (about 47°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (47°F) to its warmest (74°F).
Typical surface water temperature by month, from 14 field readings (2024–2025) via the EPA Water Quality Portal. See the full Blue Lake water temperature breakdown →
Wisconsin DNR lists Panfish as common on Blue Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Blue Lake’s water-quality measurements separately, and the water-quality trend over 7 years of monitoring is declining. 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. Monitored by volunteers since 1993. 2 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
Max depth
49 ft
Surface area
441 acres
Lake Size & Watershed
Watershed (drainage) area
79 sq mi
HydroLAKES / HydroSHEDS
Shoreline
5.8 mi
HydroLAKES / HydroSHEDS
Elevation
1,581 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Stays via Stay22
Stays near Blue Lake
Compare lakeside cabins, hotels, and vacation rentals near Blue Lake in Oneida 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 Blue Lake
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Follow Blue Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Blue 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.
Water Quality Trend: Worsening
Based on 7 years of monitoring (2020–2026).
Water clarity
Stable7 years
Phosphorus
Worsening+2.78 µg/L/yr6 years
Nearby Lakes in Oneida County
Frequently asked questions about Blue Lake
Where is Blue Lake?
- Blue Lake is a lake in Oneida County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Blue Lake?
- Blue Lake in Oneida County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 23 ft visibility. Phosphorus: 10.7 µg/L. Maximum depth: 49 ft. Surface area: 441 acres.
Is Blue Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Blue Lake?
- Blue Lake typically sits around 72°F at the surface in August, from 14 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
How deep is Blue Lake?
- Blue Lake has a maximum depth of 49 feet. The lake covers 441 acres.
What fish are in Blue Lake?
- Fish species found in Blue Lake include Panfish, Largemouth Bass, Smallmouth Bass, Walleye. Blue Lake is located in Oneida County, Wisconsin.
What did the DNR fisheries survey find at Blue Lake?
- Wisconsin DNR lists Panfish as common on Blue Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Blue Lake’s water-quality measurements separately, and the water-quality trend over 7 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
Explore Blue Lake across LakeQuality
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Where this data comes from
87 measurements from 2 monitoring stations, 2020–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX87 samples · 2020–2026
Analytical methods
- Phosphorus by Colorimetry
Monitoring station identifiers (2)
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