Wirth Lake

Wirth Lake earns a C — middle-of-the-pack water quality, with one or two parameters dragging the average down from a stronger grade. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

Mesotrophic conditions dominate at Wirth Lake: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. Wirth Lake reaches 25 ft at its deepest point — typical for Minnesota mid-sized lakes, with seasonal stratification but limited cold-water refuge. Wirth Lake is small — 40 acres alongside 1.2 miles of shoreline — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Among the 95 graded lakes in Hennepin County, Wirth Lake ranks 18 — in the top quartile locally.

Eurasian watermilfoil is established at Wirth Lake, which can dampen recreational access and pressure the native plant community. Bass fishing is part of the appeal: the species list runs to 9, anchored by largemouth and/or smallmouth bass. A documented public access point at Wirth Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. Ice-out has been logged at Wirth Lake more than two dozen times, putting the median around Apr 4 — a useful baseline for tracking climate trends. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.