Third Lake
Oneida County, Wisconsin97 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Third Lake. Here is what has been measured.
- Impaired · Mercury
- 14 ft max depth
- Limited data
Third Lake in Oneida County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 3.5 ft visibility. Maximum depth: 14 ft. Surface area: 97 acres.
Wisconsin DNR lists Panfish as common on Third Lake. DNR survey details →
Third Lake is a 97-acre lake in Oneida County, Wisconsin with a maximum depth of 14 feet. Water clarity is declining over recent sampling years. The lake supports 6 documented fish species including Musky, Panfish, and Largemouth Bass.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2023-08-21. Methodology: how these readings are compared.
What Third Lake is good for
From access and monitoring records, not editorial picks.
- Fishing6 species recorded
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Third Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
Whether Third 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 Third Lake
These are the measurements Wisconsin DNR publishes for Third 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 3.5 ft. TSI 59.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3.5ft | 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. | 59 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Third Lake
Answers come straight from the public measurements and survey records on this page.
Wisconsin DNR lists Panfish as common on Third Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Third Lake’s water-quality measurements separately, and the water-quality trend over 7 years of monitoring is stable. 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. 2 stations on file (most recent sample 2024).
Fish Species (DNR-rated)
Lake Details
Max depth
14 ft
Surface area
97 acres
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Fish Species
Click a species to see every lake where it is documented.
Fishing Third 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: Stable
Based on 7 years of monitoring (2020–2026).
Water clarity
Worsening7 years
Phosphorus
Improving-0.79 µg/L/yr7 years
EPA Impairment Status
Third 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: Fish consumption.
Source: EPA ATTAINS assessment unit WI10007459 · Official waterbody report
Nearby Lakes in Oneida County
Frequently asked questions about Third Lake
Where is Third Lake?
- Third 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 Third Lake?
- Third Lake in Oneida County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 3.5 ft visibility. Maximum depth: 14 ft. Surface area: 97 acres.
Is Third Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Third Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
How deep is Third Lake?
- Third Lake has a maximum depth of 14 feet. The lake covers 97 acres.
What fish are in Third Lake?
- Fish species found in Third Lake include Musky, Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike, Walleye. Third Lake is located in Oneida County, Wisconsin.
What did the DNR fisheries survey find at Third Lake?
- Wisconsin DNR lists Panfish as common on Third Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Third Lake’s water-quality measurements separately, and the water-quality trend over 7 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
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Where this data comes from
18 measurements from 1 monitoring station, 2020–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX18 samples · 2020–2023
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
Impairment status from EPA ATTAINS 303(d) database
Fish and recreation data from Wisconsin DNR Lakes