Shields Lake

On the scoring rubric Shields Lake grades a D: clarity at 4.4 ft and 101 µg/L of phosphorus keep it in the lower bracket for Washington County. Of the three parameters, phosphorus is the worst — at 101 µg/L of phosphorus, it keeps the lake susceptible to algal blooms in warm years.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. Shields Lake reaches 27 ft at its deepest point — typical for Minnesota mid-sized lakes, with seasonal stratification but limited cold-water refuge. The lake is compact at 30 acres, with 0.9 miles of shoreline and little volume to buffer nutrient inputs. Within the 83 graded lakes of Washington County, Shields Lake sits at rank 66, near the bottom of the county list.

No invasive species are currently listed at Shields Lake — the lake remains off the Minnesota infested-waters roster. Bass fishing is part of the appeal: the species list runs to 8, anchored by largemouth and/or smallmouth bass. The lake lacks a documented public access point, so visitor use is limited. Multiple sampling years from Minnesota PCA volunteers and partner agencies back the grade, so the letter should hold steady absent a major watershed shift.