Island Lake

Island Lake earns an F: 123 µg/L of phosphorus and clarity at 2.0 ft signal heavy nutrient loading from the surrounding watershed. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

A TSI above 70 puts Island Lake in hypereutrophic territory: visible blooms are common, and clarity rarely climbs even in early summer. Island Lake is a shallow lake at 8 ft maximum depth, which means it warms quickly, mixes constantly, and amplifies nutrient inputs. Island Lake covers 170 acres alongside 2.9 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Island Lake ranks 1 of 5 in Lyon County, putting it in the upper tier of locally monitored lakes.

Island Lake has no invasive species recorded in Minnesota state databases as of 2022, though prevention practices still apply at all access points. Walleye are documented at Island Lake, one of 6 fish species on record for the lake. A documented public access point at Island Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.