Cedar Lake
Carlton County, MinnesotaEutrophic
Cedar Lake sits at a C on the grading scale — not impaired, not pristine, with summer measurements that vary year to year. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.
At a TSI of 56, Cedar 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. Within the 33 graded lakes of Carlton County, Cedar Lake sits at rank 25, near the bottom of the county list.
No invasive species are currently listed at Cedar Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Cedar Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. The grade is supported by multiple sampling years from Minnesota PCA volunteers and partner agencies, giving the letter a reasonably stable foundation.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-07-02. Grade methodology: LakeGrade methodology.
Swimming Safety
Generally safe for swimming, moderate water quality
Water Quality Grade: C, Fair
Murky, only visible to about 4.3 ft. Phosphorus level: 40 µg/L. Chlorophyll-a: 10 µg/L. Trophic State Index: 56.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4.3 ft | D |
| Phosphorus | 40 µg/L | C |
| Chlorophyll-a (Algae) | 10 µg/L | C |
| Trophic State Index (TSI) | 56 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | +0.25 m/yr | 5 |
| Phosphorus | ↑ Improving | -20 µg/L/yr | 2 |
| Chlorophyll-a | ↑ Improving | -0.9 µg/L/yr | 5 |
Location
County Ranking
Ranked #25 of 33 lakes in Carlton County
Nearby Lakes in Carlton County
More Minnesota Lake Rankings
State Parks Near Cedar Lake
Other Grade C Lakes in Minnesota
Eutrophic Lakes in Minnesota
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2024-07-02
Monitoring stations: 1