Turtle Lake
Walworth County, Wisconsin141 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Turtle Lake. Here is what has been measured.
- Mesotrophic
- Impaired · Cause unknown
- 3 aquatic invasives
- 30 ft max depth
- Public access
Turtle Lake in Walworth County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 11 ft visibility. Phosphorus: 15.2 µg/L. Maximum depth: 30 ft. Surface area: 141 acres.
Wisconsin DNR lists Panfish as present on Turtle Lake. DNR survey details →
Turtle Lake is a 141-acre mesotrophic lake in Walworth County, Wisconsin with a maximum depth of 30 feet. Overall water quality is improving over recent sampling years. The lake supports 3 documented fish species including Panfish, Largemouth Bass, and Northern Pike. Public access is available with 1 public boat landing. Compared to the 18 other monitored lakes in Walworth County, Turtle Lake ranks #9 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-23. Methodology: how these readings are compared.
What Turtle Lake is good for
From access and monitoring records, not editorial picks.
- Clear water11 ft of visibility
- Boat launch1 documented ramp
- Fishing3 species recorded
- Deep water30 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. Turtle Lake is listed impaired under Clean Water Act §303(d) (IR 5) for cause unknown. Check local advisories before you swim.
Whether Turtle 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 Turtle Lake
These are the measurements Wisconsin DNR publishes for Turtle 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 11 ft. Phosphorus 15.2 µg/L. TSI 43.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 11ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 15.2µg/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. | 43 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Turtle Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Turtle Lake typically sits around 78°F at the surface in August. Summer average is about 79°F. Usually warmest in Jun (about 80°F) and coldest in Mar (about 46°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (46°F) to its warmest (80°F).
Typical surface water temperature by month, from 18 field readings (2024–2026) via the EPA Water Quality Portal. See the full Turtle Lake water temperature breakdown →
Wisconsin DNR lists Panfish as present on Turtle Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Turtle Lake’s water-quality measurements separately, and the water-quality trend over 7 years of monitoring is improving. 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. 1 station on file (most recent sample 2026).
Fish Species (DNR-rated)
DNR Reports & Resources
Wisconsin DNR Fisheries scientists publish multi-year survey reports for Turtle 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).
- 2021Turtle Lake spring shocking survey, 2017, 2021Spring Shocking Survey · WI DNR · 2021 (PDF)
Lake Details
Max depth
30 ft
Surface area
141 acres
Public access
Yes
Listed by Wisconsin DNR
Lake Size & Watershed
Watershed (drainage) area
2 sq mi
HydroLAKES / HydroSHEDS
Shoreline
2.2 mi
HydroLAKES / HydroSHEDS
Elevation
899 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Turtle LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Turtle Lake
Compare lakeside cabins, hotels, and vacation rentals near Turtle Lake in Walworth 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 Turtle Lake
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Follow Turtle Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Turtle 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: Improving
Based on 7 years of monitoring (2020–2026).
Water clarity
Stable7 years
Phosphorus
Improving-0.84 µg/L/yr7 years
EPA Impairment Status
Turtle 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: Aquatic life.
Source: EPA ATTAINS assessment unit WI10006234 · Official waterbody report
Nearby Lakes in Walworth County
Frequently asked questions about Turtle Lake
Where is Turtle Lake?
- Turtle Lake is a lake in Walworth County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Turtle Lake?
- Turtle Lake in Walworth County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 11 ft visibility. Phosphorus: 15.2 µg/L. Maximum depth: 30 ft. Surface area: 141 acres.
Is Turtle Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Turtle Lake is listed impaired under Clean Water Act §303(d) (IR 5) for cause unknown. Check local advisories before you swim.
What is the water temperature of Turtle Lake?
- Turtle Lake typically sits around 78°F at the surface in August, from 18 EPA Water Quality Portal field readings (2024–2026). That is a typical value for the month, not a live reading.
How deep is Turtle Lake?
- Turtle Lake has a maximum depth of 30 feet. The lake covers 141 acres.
What fish are in Turtle Lake?
- Fish species found in Turtle Lake include Panfish, Largemouth Bass, Northern Pike. Turtle Lake is located in Walworth County, Wisconsin.
What did the DNR fisheries survey find at Turtle Lake?
- Wisconsin DNR lists Panfish as present on Turtle Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Turtle Lake’s water-quality measurements separately, and the water-quality trend over 7 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Turtle Lake?
- Turtle Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Turtle Lake. Public access is listed as yes.
Can I fish at Turtle Lake?
- Turtle 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 Turtle Lake across LakeQuality
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Fish species and best lakes in Walworth County
Species activity outlook by water temperature and season
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Mesotrophic Lakes in Wisconsin
Where this data comes from
86 measurements from 1 monitoring station, 2020–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX86 samples · 2020–2026
Analytical methods
- Phosphorus by Colorimetry
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
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