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DocuSign Envelope ID: F52521E7-10C1-43F9-B62F-C1E599A5D572 <br /> • Biodegradable blankets are available for use in sensitive areas. These <br /> organic blankets are usually held together with a fiber mesh and stitching <br /> which may last up to a year. <br /> Design Criteria The following discussion and examples of design are adapted from "Green <br /> Engineering, Design Principles and Applications Using Rolled Erosion <br /> Control Products"by C.Joel Sprague. <br /> Slope Protection: Reducing raindrop and overland flow erosion. The <br /> Revised Universal Soil Loss Equation(RUSLE),as shown below,is commonly <br /> used to estimate erosion due to rainfall and sheet runoff. <br /> A= R * K* LS * C * P <br /> where: <br /> A=soil loss in tons/acre/year <br /> R=rain factor <br /> K=soil erodibility <br /> LS=topographic factor <br /> C=cover factor <br /> P=practice factor <br /> The United States Department of Agriculture's handbook, "Predicting Soil <br /> Erosion by Water: A Guide to Conservation Planning with the Revised <br /> Universal Soil Loss Equation(RUSLE), 1997,"provides agriculture-oriented <br /> values for all of these variables. Yet, when the equation is used to estimate <br /> construction-related erosion,the following unique C-and P-factors developed <br /> specifically for these applications should be used. <br /> The C-Factor—C-factors are equal to the reduction in soil loss when using <br /> a specific erosion control system when compared to the comparable bare soil <br /> (control) condition. The designer will require C-factors representing various <br /> conditions from unvegetated to fully vegetated, including vegetation, which <br /> has been mulched or,alternatively,protected by an RECP,in order to determine <br /> an appropriate factor to be used to represent the design condition. (See Table <br /> 6.17a for a range of C-factors.) <br /> 6.17.2 Rev.6/06 <br />