Water Quality of Restored Wetlands: A Study of the Great Marsh Complex in the Indiana Dunes National Lakeshore

Historic wetlands are increasingly being restored for multiple purposes, including improving water quality (WQ). The Great Marsh of the Indiana Dunes National Lakeshore (IDNL) serves as an excellent example of a restored wetland that affects WQ. Fifteen different WQ parameters have been monitored at sites throughout the Great Marsh to assess how the restored wetland is functioning. Data collected thus far indicate WQ in the restored Great Marsh is typical of a northwest Indiana wetland and that the Great Marsh is functioning like a typical wetland in this region. For example, total phosphorus analyses indicate substantial phosphorus uptake by the wetland, E. coli levels generally decrease as water passes through the marsh, and the average conductivity in the wetland is 270 µS/cm. The restored Great Marsh also experiences seasonal changes typical of a wetland, such as fluctuating water temperatures, water levels, and dissolved oxygen levels