Otrey Lake

Otrey Lake grades an F: water clarity, phosphorus, and chlorophyll-a all rate poorly, placing it among the most stressed lakes monitored in Minnesota. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

The hypereutrophic status — TSI 84 — reflects sustained heavy nutrient loading from the surrounding watershed and frequent algal pressure. Otrey Lake is a shallow lake at 8 ft maximum depth, which means it warms quickly, mixes constantly, and amplifies nutrient inputs. Otrey Lake covers 475 acres alongside 8.1 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Otrey Lake ranks 7 of 9 in Big Stone County — at the lower end of the locally monitored distribution.

Otrey Lake has no invasive species recorded in Minnesota state databases as of 2022, though prevention practices still apply at all access points. 4 fish species are on record, with panfish making up the recreational core. No formal public access is documented at Otrey 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.