Iowa
Wetlands and
Riparian
Areas
Conservation
Plan
Reclaiming abandoned mine land with
wetlands
(Poffenbarger Site, Southern Iowa)
Creating wetlands where none originally existed is a relatively new field of practice and science. The wetlands shown here, created as part of the Poffenbarger Abandoned Mine Land Reclamation Project, were designed to address the health, safety, and environmental problems caused by an abandoned coal strip mine south of Red Rock Reservoir in Marion County.
One of the largest obstacles to overcome when reclaiming abandoned mine lands is the odd chemistry of the spoils, the waste material left after the coal has been extracted. These spoils can have extremely acidic pH values. When wetlands are a necessary or desirable part of the reclamation project, this pH hurdle can be formidable because of the sensitivity of aquatic plants, invertebrates, and animals to extremely acidic pH values. In this project, wetland restoration became a part of the reclamation when the Army Corps of Engineers delineated 3.7 acres of marginal wetlands, mostly open pits in the project area. In the process of stabilizing dangerous, slumping, vertical high walls on the 96-acre site, the wetlands would be destroyed.
The same number of wetland acres had to be restored, and they also had to meet or exceed standards related to vegetation and water quality. No one knew how well the wetland plants would grow on the acidic spoils of the mine land, so 10 acres of wetlands were designed and planted in hope that half of the acreage would fully revegetate. Before the project started in the summer of 1994, the 1993 flood helped by stabilizing the pH values of the runoff water around 7 (neutral) because of the dilution effect of the immense amount of flood and rainwater. However, the soil still needed to be neutralized with lime and fertilizer. Manure was spread in the wetlands to provide a better seedbed for the wetland plants. Wetland plant plugs were placed in the constructed wetlands and seeds were sown along the shoreline in the spring of 1995.
All 10 acres of the reclaimed mine land wetlands are now thriving and host snapping turtles and migrating waterfowl. Wildlife species aren't the only ones gaining in this reclamation project; people benefit from improved water quality and reduced flooding in the nearby creeks. The vegetation is now holding the regraded spoil in place, reducing sediment loads and preventing acidic seepage from entering adjacent streams. Reducing sediment loads of the bordering creeks will reduce flooding in the creek and on the road nearby.
Contact:
- Erica Berrier, Division of Soil Conservation, Iowa Department of Agriculture &
- Land Stewardship
- Phone: (515) 281-5347
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