Green Lake
Sawyer County, Wisconsin50 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Green Lake. Here is what has been measured.
- Eutrophic
- 9 ft max depth
- Public access
Green Lake in Sawyer County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 4.7 ft visibility. Phosphorus: 34 µg/L. Chlorophyll-a (algae): 5.8 µg/L. Maximum depth: 9 ft. Surface area: 50 acres.
Wisconsin DNR lists Panfish as common on Green Lake. DNR survey details →
Green Lake is a 50-acre productive, nutrient-rich eutrophic lake in Sawyer County, Wisconsin with a maximum depth of 9 feet. Overall water quality is declining over recent sampling years. The lake supports 2 documented fish species including Panfish and Largemouth Bass. Public access is available with 1 public boat landing. Compared to the 44 other monitored lakes in Sawyer County, Green Lake ranks #32 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2021-08-23. Methodology: how these readings are compared.
What Green Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
Swimming conditions
Readings onlyModerate 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 Green 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 Green Lake
These are the measurements Wisconsin DNR publishes for Green 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 4.7 ft. Phosphorus 34 µg/L. Chlorophyll-a 5.8 µg/L. TSI 53.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 4.7ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 34µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 5.8µg/L | Good GoodFairPoor |
| 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 Green Lake
Answers come straight from the public measurements and survey records on this page.
Wisconsin DNR lists Panfish as common on Green Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Green Lake’s water-quality measurements separately, and the water-quality trend over 2 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. 1 station on file (most recent sample 1979).
Fish Species (DNR-rated)
DNR Reports & Resources
Wisconsin DNR Fisheries scientists publish multi-year survey reports for Green Lake covering fish populations, stocking, water quality, and management. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- 2023Mason and Evergreen lakes spring netting and shocking survey, 2023Netting Survey · WI DNR · 2023 (PDF)
Lake Details
Max depth
9 ft
Surface area
50 acres
Public access
Yes
Listed by Wisconsin DNR
Lake Size & Watershed
Watershed (drainage) area
0 sq mi
HydroLAKES / HydroSHEDS
Shoreline
1.1 mi
HydroLAKES / HydroSHEDS
Elevation
1,335 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Green LakeSemi-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 Green Lake
Compare lakeside cabins, hotels, and vacation rentals near Green Lake in Sawyer 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 Green Lake
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Follow Green Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Green Lake
Water quality readings over time
2 seasons of samples on record (2020–2021). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Improving2 years
Phosphorus
Worsening+8 µg/L/yr2 years
Chlorophyll-a
Worsening+1.3 µg/L/yr2 years
Nearby Lakes in Sawyer County
Frequently asked questions about Green Lake
Where is Green Lake?
- Green Lake is a lake in Sawyer County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Green Lake?
- Green Lake in Sawyer County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 4.7 ft visibility. Phosphorus: 34 µg/L. Chlorophyll-a (algae): 5.8 µg/L. Maximum depth: 9 ft. Surface area: 50 acres.
Is Green Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Green Lake?
- Green Lake has a maximum depth of 9 feet. The lake covers 50 acres.
What fish are in Green Lake?
- Fish species found in Green Lake include Panfish, Largemouth Bass. Green Lake is located in Sawyer County, Wisconsin.
What did the DNR fisheries survey find at Green Lake?
- Wisconsin DNR lists Panfish as common on Green Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Green Lake’s water-quality measurements separately, and the water-quality trend over 2 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Green Lake?
- Green Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Green Lake. Public access is listed as yes.
Can I fish at Green Lake?
- Green Lake 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 Green Lake across LakeQuality
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Where this data comes from
27 measurements from 1 monitoring station, 2020–2021. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Lac Courte Oreilles (Tribal)
LCOWIS_WQX27 samples · 2020–2021
Analytical methods
- 4500 P E ~ Phosphorus in Water by Colorimetry- Ascorbic Acid Method
- 2320 B ~ Alkalinity by Gran Titration
- 10200 H ~ Chlorophyll a-b-c Determination
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Fish and recreation data from Wisconsin DNR Lakes
Named boat-access points from the USGS National Boat Ramps inventory