Lake Assessment Program Spirit Lake, Wadena County, Minnesota

Spirit Lake is a moderate-sized land-locked lake located in Wadena County. It has a surface area of 116 acres. The total watershed for this lake is about 0.2 square miles. Land use in the watershed is characterized primarily by urban (95 percent) use. This percentage is very high for lake watersheds in this region of the state - North Central Hardwood Forests ecoregion. Spirit Lake was sampled during the summer of 1997 by the Minnesota Pollution Control Agency (MPCA) staff and citizens from the City of Menahga (Municipality). Water quality data collected during the study reveal summer-mean total phosphorus (TP) concentration of 16 ?g/L, mean chlorophyll a of 3.2 ?g/L and Secchi transparency of 17.1 feet for Spirit Lake. The phosphorus, chlorophyll a and Secchi values for Spirit Lake are better than the range of values exhibited by reference lakes in this ecoregion. Total phosphorus, chlorophyll a and Secchi transparency help to characterize the trophic status of a lake. These measures indicate mesotrophic conditions for Spirit Lake.