Bass Lake
St. Louis County, MinnesotaLimited DataEutrophic
Bass Lake earns a D — measurements through 2024 show persistent nutrient pressure that limits clarity through the summer.
At a TSI of 56, Bass Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. 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. Bass Lake ranks 160 of 187 in St. Louis County — at the lower end of the locally monitored distribution.
An invasive species record — spiny waterflea — has been logged at Bass Lake; Minnesota PCA maintains the official infested-waters list. The state fisheries records do not list documented species for Bass Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. A documented public access point at Bass Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-08-31. Grade methodology: LakeGrade methodology.
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Swimming Safety
Swimming not recommended, poor water quality with high algae risk
Water Quality Grade: D, Poor
Murky, only visible to about 4.2 ft. Trophic State Index: 56.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4.2 ft | D |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 56 | Eutrophic |
High nutrients, frequent algae, reduced clarity
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: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.084 m/yr | 5 |
Location
County Ranking
Ranked #160 of 187 lakes in St. Louis County
Cleaner Lakes Within 30 Miles
Bass Lake holds Grade D. One nearby lake has a higher grade.
Nearby Lakes in St. Louis County
More Minnesota Lake Rankings
State Parks Near Bass Lake
Other Grade D Lakes in Minnesota
Eutrophic Lakes in Minnesota
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Bass Lake. 1 report on file.
- —Public Water Access Sites — East VermilionPublic Water Access Sites · MN DNR LakeFinder
EPA Impairment Status
Bass Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN69-0378-01 · Official waterbody report · Matched by proximity (0.9 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
Most recent sample: 2024-08-31
Monitoring stations: 1