The organisms in wetlands can use or retain agricultural nutrients and process chemical and organic wastes. The fractive surfaces of wetland plants and slow-moving or still waters also settle out sediments eroded from uplands. Research indicates that a wetland environment increases the quality of water before discharging it into streams and creeks or before it percolates through the soil. Lush vegetation and abundant microbial life are characteristic of healthy wetlands. This means that 1 acre of Iowa wetland removes excess amounts of nitrogen in runoff from 100 acres of corn ground.
Wetlands are important in recharging groundwater supplies.
Such recharging is important because groundwater is used extensively in Iowa for drinking water and agriculture. Wetlands help maintain water tables and stream-base flows, keeping groundwater levels sufficiently recharged. Wetlands also can be managed to store storm runoff and floodwater, thereby protecting adjacent and downstream property from flood damage. Draining wetlands eliminated much of Iowa's water storage capacity. Wetlands could instead be used as a collection point for tile drainage systems.