Winkle Lake
Winkle Lake in St. Louis County, Minnesota has a water quality grade of C (Fair). Phosphorus: 26.5 µg/L. Chlorophyll-a (algae): 4.7 µg/L.
- Max depth
- ~29 ft est.
- Type
- Mesotrophic
- Trend
- ↓ Declining
- Public access
- Yes
- Ice-out
- Apr 30
Next lake in St. Louis County
Winkle Lake is a mesotrophic lake in St. Louis County, Minnesota with an estimated average depth of about 29 feet. Water quality is graded C based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 67 other monitored lakes in St. Louis County, Winkle Lake ranks #63 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-07-20. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLimited data
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
No clarity data. Phosphorus level: 26.5 µg/L. Chlorophyll-a: 4.7 µg/L. Trophic State Index: 49.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | 26.5 µg/L | Fair |
| Chlorophyll-a (Algae) | 4.7 µg/L | Good |
| Trophic State Index (TSI) | 49 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Winkle Lake
Compare lakeside cabins, hotels, and vacation rentals near Winkle Lake in St. Louis County, Minnesota — 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.
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Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~29 ft est. |
| Average Depth | ~7 ft est. |
| Public Access | Yes |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Minnesota has not published bathymetry for Winkle Lake.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Recreation & Access
- LeoraPublic
Fishing Winkle Lake
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.315 m/yr | 6 |
| Phosphorus | ↑ Improving | -2.91 µg/L/yr | 6 |
| Chlorophyll-a | ↓ Declining | +0.29 µg/L/yr | 6 |
Ice Season
Historical ice data from Minnesota DNR (7 observations).
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2019-04-20 (2019) | 2022-05-03 (2022) |
| Ice-In | 2022-11-16 (2022) | 2023-11-23 (2023) |
Most recent ice-out: 2023-04-30
EPA Impairment Status
Winkle Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN69-0521-00 · Official waterbody report · Matched by proximity (0.81 km)
County Ranking
Ranked #63 of 68 lakes in St. Louis County
Nearby Lakes in St. Louis County
Frequently asked questions about Winkle Lake
What is the water quality grade for Winkle Lake?
- Winkle Lake in St. Louis County, Minnesota has a water quality grade of C (Fair). Phosphorus: 26.5 µg/L. Chlorophyll-a (algae): 4.7 µg/L.
Is Winkle Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Winkle Lake has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 4.7 µg/L. Always check local health department advisories before swimming.
How deep is Winkle Lake?
- No published bathymetric survey covers Winkle Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 29 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
When does Winkle Lake thaw?
- Winkle Lake typically has ice-out around Apr 30.
Are there boat ramps on Winkle Lake?
- Winkle Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Leora. Public access is listed as yes.
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Where this data comes from
12 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA12 samples · 2020–2025
Analytical methods
- Phosphorus by Two Reagent Colorimetry
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory
Ice data from Minnesota DNR Climate