Wetlands provide valuable ecosystem services, including water storage and filtration, and have many economic benefits such as flood control, wastewater treatment, and recreation. Unfortunately, much of the original wetland habitat in the United States has been lost. In the Midwestern U.S. state of Illinois, over 90% of original wetland acreage has been converted for urbanization and agriculture, the latter accounting for 75% of the state’s land area. Approximately 39% of Illinois’ agricultural acres are tile-drained, providing a direct pathway for dissolved nutrients to adjacent waterways via a network of subsurface drainage pipes. This emphasizes the importance of edge-of-field practices, specifically practices that intercept and treat tile-drainage water, in reducing nutrient contributions to the Gulf of Mexico. Constructed wetlands have shown to be an effective edge-of-field practice by reducing nitrate-nitrogen and dissolved phosphorus levels from subsurface drainage water, but adoption of wetlands as an agricultural conservation practice remains low.
Over the past 17 years, The Nature Conservancy and partner organizations in Illinois have worked with landowners and farmers to install small constructed wetlands for cropland tile-drainage treatment under USDA Farm Bill programs. We encountered challenges with landowner outreach, wetland construction and maintenance, and overall programmatic efficiencies during this time, but also gained valuable experience in streamlining these processes while improving wetland functionality and resiliency. In this presentation, we will share our first-hand experiences on the design, implementation, operation, maintenance, and monitoring of constructed wetlands, along with recommendations to improve landowner assistance and engagement for this practice. The overall goal of this work is to support landowners and conservation professionals working in tile-drained areas in increasing the rate and scale of constructed wetland and other edge-of-field practice implementation for improved water quality.