Long Lake
Oconto County, WisconsinView mapDirections
Wisconsin DNR publishes the water-quality measurements for Long Lake. Here is what has been measured.
- Public access
- Limited data
Long Lake in Oconto County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 14.5 ft visibility. Phosphorus: 10.2 µg/L.
Long Lake is a lake in Oconto County, Wisconsin. Limited fish-species data available. Public access is available.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2022-09-14. Methodology: how these readings are compared.
What Long Lake is good for
From access and monitoring records, not editorial picks.
- Clear water14.5 ft of visibility
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Long 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 Long Lake
These are the measurements Wisconsin DNR publishes for Long Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 14.5 ft. Phosphorus 10.2 µg/L. TSI 38.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 14.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 10.2µg/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. | 38 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Long Lake
Answers come straight from the public measurements and survey records on this page.
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Fishing Long Lake
Water Quality Trend: Stable
Based on 7 years of monitoring (2020–2026).
Water clarity
Stable7 years
Phosphorus
Stable-0.21 µg/L/yr7 years
Nearby Lakes in Oconto County
Frequently asked questions about Long Lake
Where is Long Lake?
- Long Lake is a lake in Oconto County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Long Lake?
- Long Lake in Oconto County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 14.5 ft visibility. Phosphorus: 10.2 µg/L.
Is Long Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Can I fish at Long Lake?
- Public access to Long 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
7 measurements from 2 monitoring stations, 2021–2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX7 samples · 2021–2022
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.