Peter Lake
Hennepin County, MinnesotaEutrophic
On the LakeGrade scale Peter Lake grades a B, with clarity at 9.9 ft and 43 µg/L of phosphorus placing it above the Minnesota median. clarity and phosphorus rate similarly, so there is no obvious single lever to pull on watershed management.
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. Within Hennepin County's 95 graded waters, Peter Lake sits at rank 10, near the top of the local distribution.
No invasive species are currently listed at Peter Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Peter Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. No formal public access is documented at Peter Lake — most use is by shoreline residents and their guests. 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 2023-10-03. Grade methodology: LakeGrade methodology.
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Swimming Safety
Good for swimming, clear water with low algae levels
Water Quality Grade: B, Good
Good clarity, visible to about 9.9 ft. Phosphorus level: 43.4 µg/L. Trophic State Index: 51.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 9.9 ft | B |
| Phosphorus | 43.4 µg/L | C |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 51 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Water Quality Trend: ↑ Improving
Based on 3 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.99 m/yr | 3 |
| Phosphorus | ↑ Improving | -12.8 µg/L/yr | 3 |
Location
County Ranking
Ranked #10 of 95 lakes in Hennepin County
Nearby Lakes in Hennepin County
More Minnesota Lake Rankings
State Parks Near Peter Lake
Other Grade B Lakes in Minnesota
Eutrophic Lakes in Minnesota
EPA Impairment Status
Peter 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 MN27-0147-02 · Official waterbody report · Matched by proximity (0.07 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: 2023-10-03
Monitoring stations: 1