A wetland is a marsh-type area with saturated soils and water-loving plants. Wetlands can be constructed for the purpose of removing nutrients because they filter nutrients, chemicals, and sediment from runoff or tile water before water moves off of a farm field and into streams and rivers. Because wetlands slow overland flow and store runoff water, they reduce both soil erosion and flooding downstream. Many wetlands release water slowly into the ground which recharges groundwater supplies.
Wetlands provide habitat for waterfowl and many other species of wildlife, as well as add beauty and value to a farm. Wetlands can be built or enhanced by installing practices such as dikes to manage water levels.
Wetlands targeted for water quality benefits show great potential for nitrate-N reduction. Wetland costs include design, construction, buffer seeding, maintenance and land acquisition. In addition to water quality benefits, these wetlands provide other benefits such as improved aesthetics and habitat.
Nature's Kidneys: The Illinois Water Resources Center discuss how constructed wetlands filter nitrogen and benefit wildlife in the video below.