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Erosion Control Matting <br />Jute mesh, excelsior matting, erosion- <br />control fabric, or other matting is used to <br />prevent erosion on previously shaped and <br />seeded soils, soil-covered drainage channels <br />and slopes, or other critical areas. The basic <br />objective of erosion-control matting is to <br />provide a stable seedbed for one or more <br />growing seasons. Some are designed to last <br />longer than others. Erosion-control matting <br />disperses raindrop impact, then biodegrades <br />and disappears as vegetation is established. <br />Basic Design and <br />Construction} Criteria <br />Figure 4.1: Excelsior matting is laid loosely over <br />the seeded slopes. Bear Canyon Mine. <br />Erosion-control matting or blankets can be used on slopes steeper than 2'h <br />horizontal to 1 vertical (2.5:1) or areas where maximum soil surface stabilization is desired, <br />such as soils that are adjacent to waterways. Matting is laid parallel to the slope and <br />staked down. Recommended installation will vary, depending on the product purchased. <br />Some matting is anchored at the top of the slope in a trench that is 6" deep and 6" wide, <br />while other products require no trenching. The matting should be laid loosely because it <br />tends to shrink and stretch over high points. <br />In high wind areas and loose soils, the staples supplied by manufactures can easily <br />come loose and the blanket can blow away. Surveying stakes can provide a stronger hold. <br />Remove surveying stakes after the netting has deteriorated. <br />photodegradation: <br />the process of <br />breaking down due to <br />the' effects of ultra <br />violet sunlight. <br />Small-squared netting can trap and kill snakes. Snakes <br />are beneficial on reclaimed areas because they control rodent <br />populations. The photodegradation of the plastic.in the netting <br />can take up to ten years. Since netting can be detrimental to <br />wildlife, reclamation projects should use netting with holes larger <br />than 2" and a 2 year photodegradation life. <br />Site Preparation <br />Areas needing erosion-control matting should have been previously shaped and <br />seeded. Except in drainages, the soil surface should be left in a very roughened condition. <br />Materials <br />Staples should be No. 11 gauge new steel wire, formed into a six to ten-inch long <br />"U" shape. Use surveying stakes on loose, unstable soils. When selecting erosion-control <br />matting, select fabric mats with a life expectancy equal to the length of time it will take for <br />vegetation to establish and take over erosion-control. <br />116: