Erosion Control
Changing land uses have caused alterations in our soil and water. Erosion of soils from our land is a major contributor of pollutants to our lakes and rivers. Many pollutants will bind to soil particles and be transported to waterbodies. Although erosion is a natural process, human-induced alterations to the land and at the water's edge have dramatically increased soil erosion rates. A loss of vegetative cover exposes soils, and the loss of root structure allows soil to easily erode. Increases of sediment and pollutants in lakes and streams can degrade habitat for plants and animals. This is evident in the Mississippi River delta where a large hypoxic zone, formed through the introduction of excess nutrients, mostly from non-point sources, now covers 8,000 square miles.
Erosion Control With Soil
Bio-Engineering
Soil Bio-engineering is the use of plants and plant parts as the primary structural component to reinforce soil and stabilize slopes. Soil Bio-engineering can be used on rivers, streams, lakes, ponds and upland slopes. Soil Bio-engineering methods are effective at reducing bank erosion & stabilizing banks, improving aquatic & terrestrial habitat, increasing riparian corrdior continuity, and improving soil quality. Branches and leaves are effective at slowing the velocity of the water and armoring the soil surface. Types of plants used are dormant un-rooted hardwood cuttings, rooted plants, seed, transplant plugs, rhizomes and clump plantings. A diverse mixture of plant types should be used to ensure plant survival success. If planned and installed properly Soil Bio-engineering is cost-effective, relatively simple to install, and self-repairing.
Soil Bio-engineering should not be used when entire stream systems are unstable, increased flow resistance would cause increased flood levels, excessive velocities exist, high-risk settings and in areas that would not be likely to sustain plant growth.
Soil Bio-engineering is not a new concept. Willow cuttings were used for bank stabilization in Europe in the 1500's and were also used in China centuries earlier along the Yangtze River.
