Lake Assessment Program - Lake Minnewaska, Pope County

Lake Minnewaska is located near the cities of Glenwood and Starbuck in Pope County. With a surface area of over 7,700 acres. it is among the top ten percent of lakes in the state in terms of size. However, With a maximum depth of 32 feet it is relatively shallow. The total watershed is about 90 square miles, which includes the Trappers Run Watershed. Lake Minnewaska is located in the North Central Hardwood Forest (NCHF) ecoregion. Land use in the watershed is characterized primarily by pasture (16 percent), and cultivated (52 percent) uses. These percentages are typical for lake watersheds in this region of the state - North Central Hardwood Forests ecoregion. The relative impact of the cultivated and pastured lands on the phosphorus loading to the lake may have been lessened through land retirement in the Conservation Reserve Program (CRP) and recent reductions in the dairy herds in the watershed prior to this study. Lake Minnewaska was sampled during the summer cf I 995 by the Minnesota Pollution Control Agency (MPCA) and citizens from the Lake Minnewaska Improvement Association (Association). Water quality data collected during !he study reveal summer-mean total phosphorus (TP) concentrations of 24 ug/L, chlorophyll a of 9.4 ug/L and Secchi transparency of 9.I feet. All three measures are within the range of values exhibited by reference lakes in the NCHF ecoregion. Total phosphorus, chlorophyll a and Secchi transparency help to characterize the trophic status of a lake These measures indicate borderline mesotrophic - eutrophic conditions for Lake Minnewaska.