Little Johanna Lake

On the scoring rubric Little Johanna Lake grades a D: clarity at 4.6 ft and 65 µg/L of phosphorus keep it in the lower bracket for Ramsey County. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. The lake bottoms out at 28 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. The lake is compact at 17 acres, with 0.7 miles of shoreline and little volume to buffer nutrient inputs. Within Ramsey County's 51 graded lakes, Little Johanna Lake ranks 32 — below the local median, though not at the bottom.

Little Johanna Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Little Johanna Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. No formal public access is documented at Little Johanna Lake — most use is by shoreline residents and their guests. Multiple sampling years from Minnesota PCA volunteers and partner agencies back the grade, so the letter should hold steady absent a major watershed shift.