Penn Lake

Penn Lake pulls a D on the LakeGrade rubric — phosphorus loading and limited clarity hold it below the Minnesota average. Clarity is the limiting factor — phosphorus is reasonable but suspended particles or algal cells keep water transparency below Minnesota norms.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. At only 7 ft deep, Penn Lake is shallow — wind keeps the water column mixed and sediment resuspension drives phosphorus levels harder to manage. Penn Lake is small — 44 acres alongside 2.3 miles of shoreline — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Among the 104 graded lakes in Hennepin County, Penn Lake sits at rank 35, above the county median.

No invasive species are currently listed at Penn Lake — the lake remains off the Minnesota infested-waters roster. The fishery is panfish-dominated — bluegill, crappie, and sunfish among the 8 species documented for the lake. A documented public access point at Penn Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. Multiple sampling years from Minnesota PCA volunteers and partner agencies back the grade, so the letter should hold steady absent a major watershed shift.