Author
Cooper, Charles | |
HUDSON, CHARLES - DOD | |
Shields Jr, Fletcher |
Submitted to: Meeting Abstract
Publication Type: Proceedings Publication Acceptance Date: 4/1/1996 Publication Date: N/A Citation: N/A Interpretive Summary: A major problem with off-site damages from agricultural land is sediment. Sediment originates from farm fields and stream channels. Channel incision is a continuing source of sediment in the hill lands that drain into the Mississippi River alluvial delta. This incision separates streams from their floodplains, destroys arable land, and degrades environmental resources. A federal interagency demonstration project dealing with channel erosion was begun in 1984 in the loess hill lands of northwestern Mississippi, USA. Congress directed this project, the Demonstration Erosion Control (DEC) Project in the Yazoo Basin, so that design and construction activities are the responsibility of the Corps of Engineers, Vicksburg District and the Natural Resource Conservation Service (USDA). The Agricultural Research Service (USDA) evaluated stream stabilization/rehabilitation technology in 15 watersheds characterized by erosion and sedimentation associated with channel incision as part of the project. We found that some stream stabilization measures could be used as are or modified for environmental improvement with little or no cost increase. While the project continues, technology transfer of results already produced allows federal and state agencies across the country to make immediate use of the results. The results are being placed in a federal interagency stream restoration handbook. Technical Abstract: Channel incision is a continuing source of sediment in the hill lands that drain into the Mississippi River alluvial delta. This incision separates streams from their floodplains, destroys arable land, and degrades environmental resources. A federal interagency demonstration project dealing with channel erosion was begun in 1984 in Mississippi. Congress directed the Demonstration Erosion Control (DEC) Project in the Yazoo Basin so that design and construction activities are the responsibility of the Corps of Engineers, and USDA-NRCS. Evaluation of project measures is done by the Agricultural Research Service (USDA) and CE Waterways Experiment Station. The major project objective centered on developing stabilization/rehabilitation technology in 15 watersheds characterized by erosion and sedimentation associated with channel incision. Stream channels were typically straight due to past (ca.1880 to 1970) channelization, enlarged by erosion, and have little woody debris, pool habitat, or stable substrate. Common measures included field-scale grade control pipes, stream grade controls, bank protection, and floodwater-retarding reservoirs. Channel cleanout and levees were less customary. Aquatic habitat studies at >100 sites showed that major needs included greater water depth and improved habitat stability. Based on increases in water depth and number of species and biomass, grade control structure energy-dissipation pools, stone spur dikes, and V-shaped stone weirs improved in-stream habitat. Field-scale grade controls and sediment retention ponds created wetland and open water habitats for all classes of vertebrates. Success of woody vegetation plantings willow varied with site. |