Information on Maple Marsh

100-Yr. Flood Elev 974.5 (FEMA) 

Maple Marsh is a shallow lake surrounded by a large, private livestock grazing operation.  There is no public access to the lake.  In the past the lake has been subjected to considerable nutrient-laden runoff and erosion due to historic logging and farming practices.  The lake likely has a high internal loading rate for phosphorus.  When the District last monitored for in-lake phosphorus concentrations in 2001 concentrations were significantly worse than the MPCA shallow lake standard of (60mg/L).  In 2007 the lake met the MPCA shallow lake standard of 1 m for Secchi depth transparency.