Black Lake

The LakeGrade rubric puts Black Lake at a C: clarity at 6.9 ft, 36 µg/L of phosphorus, and a TSI of 53 signal an intermediate trophic state. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. 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. Among the 49 graded lakes in Ramsey County, Black Lake sits at rank 19, above the county median.

No invasive species are currently listed at Black Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Black Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. No formal public access is documented at Black Lake — most use is by shoreline residents and their guests. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.