Andrus Lake

Andrus Lake carries a solid B grade — strong on most parameters, with measurements that hold up well across the summer season. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

The lake sits in the mesotrophic zone — the band where most well-managed Minnesota lakes fall. At 55 ft of maximum depth, Andrus Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. Andrus Lake is small — 56 acres alongside 1.7 miles of shoreline — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Within Cass County's 133 graded lakes, Andrus Lake ranks 94 — below the local median, though not at the bottom.

Andrus Lake has no invasive species recorded in Minnesota state databases as of 2020, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Andrus Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. No formal public access is documented at Andrus 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.