Cooperative Fish and Wildlife Research Units Program: Iowa
Education, Research and Technical Assistance for Managing Our Natural Resources

Iowa Project

Effects of Tile Drainage on Restored Oxbows as Habitat for Endangered Topeka Shiners and other Biota

January 2019 - December 2021


Participating Agencies

  • Iowa Soybean Association

Oxbow restoration has been shown to promote conservation of the endangered Topeka shiner and enhance agricultural floodplain habitat for other taxa, while parallel research has identified oxbow restoration as a potentially effective strategy for reducing nutrient export from cropland to Iowa's waterways. Because of this potential benefit, oxbow restoration was recently adopted by the Science Advisory Team of the Iowa Nutrient Research Center (INRC) as an approved conservation practice, which will accelerate its proliferation on the landscape. The nutrient reduction effectiveness of these restored oxbows depends on their interception of tile drainage before it reaches natural waterways, and future oxbows restored under the INRC program will be fed by tiles. However, an important and as yet unanswered question is whether introduction of tile drainage will affect the conservation benefits of restored oxbows. Numerous agencies are partners in this research and will benefit from its results, including the U.S. Fish and Wildlife Service, The Nature Conservancy, The Iowa Soybean Association, and the Iowa Department of Natural Resources. This research will quantify the establishment of biota and habitat conditions in recently restored oxbows, with and without tile drainage, to test the effects of tile drainage on conservation benefits of oxbow restoration.