When glacial floods reached the placid water of the ancient glacial lake, the velocity dropped so drastically that sediment built distally as a delta. Though a rarity in such a small area, Glacial Park contains all three types of kettle lake remnant wetlands- fens, bogs and marshes. The park has an elevated fen, and well-developed stream, bog, and marsh ecosystems. It also has prairie and oak savanna ecosystems. Many plant and animal communities flourish here, with wetlands being the prime ecosystem.
Wetlands help control flooding and protect the water quality.
This helps maintain the water table level and aids in the recharge of groundwater. Wetlands also remove sediment, nutrients, and toxic chemicals from runoff water and are valued for recreational purposes. The wetland depressions in Glacial Park formed, about 14,000 years ago, around the tail end of the Pleistocene ice age. In time, without any stream recharge or channel outflow, these shallow depressions, partially dried up to form fens, bogs, and marshes. Plant communities such as skunk cabbage, for example, prefer soggy, alkaline conditions and thrive in fens.