Riverbank Restoration with Native Wildflowers and Turf Reinforcement Mats

摘要

In 2002, the City of Indianapolis, Indiana was presented with a problem along the White River shoreline. Riverbank erosion was exposing landfill waste as well as a petroleum pipeline. Due to limited space within the city limits, the landfill was positioned on land adjoining the river, and the pipeline was located following the natural banks of the river. Because of their proximity to the natural waterway, any shoreline erosion posed a threat to the environmental quality of the water. With EPA funding available for only a short time, the City of Indianapolis needed a quick and affordable solution. Restoration of the shoreline with native vegetation that included a wide range of wildflowers was a critical factor to the City. They found a solution in a permanent polypropylene fiber composite turf reinforcement mat. Installation began in April 2003 and continued until October 2003. During the course of the project, the area was subjected to six high flow water events, the first in April and the last, a 9 inch rainfall on Labor Day. After many of the storm-events, the complete inundation of the river's shoreline lasted 15 days or more. Even with the heavy flows, the TRM did not fail to stabilize the shoreline, and the native vegetation was protected during early establishment. The vegetation used in conjunction with the C-TRM included Graminoids (Sedges, Bottlebrush grass, wild ryes, and switch grass, etc) and Wildflowers (columbine, butterfly weed, asters, coreopsis, coneflowers, and goldenrod, etc). There was some concern during the vegetation selection process and if the broadleaf plants would be able to grow through the C- TRM. The concerns were quickly relieved after high germination rates and quick establishment of the shoreline occurred within three months. Now three years after the project was completed, the riverbank has been permanently restored, and the landfill contents are safely secured from exposure next to the river. The petroleum pipeline also has been concealed, reducing the chances of conveyance lines being damaged and the potential for dangerous accidents.