Lake Assessment Program - Wolf Lake, Lake County

Wolf (Johnson) Lake is located in the Lake Superior Highlands, 5 miles southeast of Finland, Minnesota. The lake has a surface area of about 30 acres, a maximum depth of 24 feet and a mean depth of approximately 15 feet. The total watershed area is approximately 160 acres (0.25 square miles). Land use in the watershed is characterized primarily by forested land, with approximately 15 acres of developed land owned by Wolf Ridge Environmental Learning Center (classrooms, dormitories, cafeteria, and administrative buildings). Wolf Lake was sampled during the summer of 2005 by the Minnesota Pollution Control Agency (MPCA) staff, with assistance from Wolf Ridge. Water quality data collected during the study reveal a summer-mean total phosphorus (TP) concentration of 17 ?g/L, chlorophyll a of 3 ?g/L and Secchi transparency of 12.1 feet. All three measures are well within the range of values exhibited by reference lakes in the NLF ecoregion. Total phosphorus, chlorophyll a and Secchi transparency help to characterize the trophic status of a lake. These measures indicate mesotrophic – conditions for Wolf Lake. Chloride concentrations (4.2 mg/L) were significantly higher than the ecoregion range of 0.6 – 1.2 mg/L. The elevated chloride levels likely originate from Wolf Ridge's overloaded septic system or road salt runoff.