Winkle Lake
St. Louis County, MinnesotaLimited DataEutrophic
Winkle Lake sits at a C on the grading scale — not impaired, not pristine, with summer measurements that vary year to year.
A TSI in the eutrophic range signals a lake doing what nutrient-loaded waters do — supporting an active algal community at the cost of clear water. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake's surface area is not consistently recorded across state datasets — physical context remains partial. Winkle Lake sits at rank 132 of 187 in St. Louis County, in the lower half of the local distribution.
No invasive species are currently listed at Winkle Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Winkle Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. The lake lacks a documented public access point, so visitor use is limited. The lake has a partial ice record — 5 observed ice-outs, centered near Apr 30. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-07-14. Grade methodology: LakeGrade methodology.
Track Winkle Lake
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Generally safe for swimming, moderate water quality
Water Quality Grade: C, Fair
No clarity data. Phosphorus level: 32 µg/L. Trophic State Index: 54.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No data | |
| Phosphorus | 32 µg/L | C |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 54 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Water Quality Trend: → Stable
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.359 m/yr | 5 |
| Phosphorus | ↑ Improving | -3.01 µg/L/yr | 5 |
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
Location
County Ranking
Ranked #132 of 187 lakes in St. Louis County
Cleaner Lakes Within 30 Miles
Winkle Lake holds Grade C. 2 nearby lakes hold higher grades.
Nearby Lakes in St. Louis County
More Minnesota Lake Rankings
Other Grade C Lakes in Minnesota
Eutrophic Lakes in Minnesota
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)
Data Sources
Water quality data from the EPA Water Quality Portal
Impairment status from EPA ATTAINS 303(d) database
Grading methodology based on Metropolitan Council standards
Ice data from Minnesota DNR Climate
Most recent sample: 2024-07-14
Monitoring stations: 1