Lake Assessment Program - Jefferson Lake and German Lake, LeSueur County

Jefferson and German Lakes are located in Lesueur County in south central Minnesota near the city of Cleveland. Jefferson Lake is characterized by four distinct basins and combined with German Lake to form a chain of interconnected basins. German Lake is the last lake in the chain and outlets to the Cannon River. Jefferson is a relatively large lake, approximately 2,300 acres in size and German Lake is about one half the size (910 acres). Both lakes are relatively shallow, 81 percent of Jefferson Lake is in the littoral area (area of the lake less than 15 feet deep) and German Lake has a littoral area of 58 percent. The watershed is not relatively large (27 mi 2 ) compared to the surface area of the lake (5.4:1 ratio). The watershed is characterized primarily by agricultural land uses (SS percent) and water and marsh uses (31 percent). These land uses are typical for lakes in this part of the state which is referred to as the North Central Hardwood Forest ecoregion (NCHF). Jefferson and German Lakes were sampled during the summer of 1990 by the Minnesota Pollution Control Agency (MPCA) staff and citizens from the Greater Jefferson-German Lake Association as a part of the Lake Assessment Program (LAP). Water quality data collected during this study indicates that German Lake is eutrophic and Jefferson Lake is hypereutrophic.