Environmental Review Toolkit
Water, Wetlands, and Wildlife

see caption
View of wetland bank showing grasses, sedges, and other water plants. (AHTD)
egrets and other birds in wetland
The wetland mitigation area is used by egrets and other bird species. (AHTD)

Arkansas Highway and Transportation Department

Arkansas' Ecoregion-Based Approach to Wetlands Mitigation

The State of Arkansas once had an estimated 9.8 million acres of wetlands—almost 30 percent of the State's total surface area. By the mid-1980s, the number of wetlands had dropped to 2.8 million acres covering only 8 percent of the land. East Arkansas' Delta Ecoregion experienced the greatest losses. Out of an original 8 million acres of forested wetlands, only about 875,000 acres remain. This staggering 89% loss is greater than any other inland State in the Nation.

To help offset wetland losses, the Arkansas Highway and Transportation Department (AHTD) has set up wetland mitigation banks in the State's five ecoregions: the Ozark Highlands, the Arkansas River Valley, the Ouachita Mountains, the Gulf Coastal Plain, and the Delta Ecoregion (the Mississippi Alluvial Plain). These large areas support a geographically distinct assemblage of ecosystems that share similar environmental conditions and most of the same species and ecological dynamics.

Since 1996, AHTD has established one bank in each ecoregion and created eleven other mitigation areas—a total of nearly 3,020 acres. The banks were created through collaboration among AHTD, FHWA, the U.S. Army Corps of Engineers, the U.S. Fish and Wildlife Service, the Natural Resources Conservation Service, the U.S. Environmental Protection Agency, the Arkansas Game and Fish Commission, the Arkansas Natural Heritage Commission, and the Arkansas Soil and Water Commission.

Federally threatened bald eagles and various migrating waterfowl species use the bank sites, where hunting and fishing are not allowed. AHTD has attached wooden raptor platforms to the tops of telephone poles—perfect "stages" from which red-tailed hawks and other birds of prey can hunt and on which they can feed.

On the 235-acre Rixey Bayou site in central Arkansas, AHTD crews built wildlife underpasses and installed protective fences for migrating turtles and small mammals. They even sank discarded Christmas trees in ponds to create fish habitat.

Future efforts to establish another mitigation bank within the Ozarks Highlands Ecoregion will likely focus on protecting the habitats of endangered Cave Crayfish and Ozark Cavefish, which occur in the Karst (limestone) formations found here.

Investing in ecoregion-based wetland mitigation means investing in places that have the best sites and the highest potential for success. For example, Arkansas' Multi-Agency Wetland Planning Team selected the 160-acre Hartman Bottoms Wetland Mitigation Bank in the Arkansas River Valley Ecoregion because it offered the greatest number of benefits to wetlands and wildlife habitat. By taking a landscape-scale or ecoregion approach and contributing a larger bank site rather than many small sites into the overall ecology of the area, the project provided ecological connectivity and prevented further environmental fragmentation.

For more information, contact Phillip Moore at phillip.moore@arkansashighways.com

HEP Home Planning Environment Real Estate

Federal Highway Administration | 1200 New Jersey Avenue, SE | Washington, DC 20590 | 202-366-4000