Laserfiche WebLink
each location which had the parameters described in the previous section. All ponds were <br />designed to fully contain the 25 year 24 hour event. Ponds 015, 016, and 018 are designed to <br />contain the 100 year 24 hour event. <br />Shown on the following two pages are the calculations used by Carlson Software in determining <br />typical pond volumes. <br />Universal Soil Loss Equation: Used by Carlson Software <br />Required User Input: <br />Note: The following values are to be entered by the user for each area in the watershed. The <br />method for obtaining these parameters is left to the user. <br />Rainfall Factor (R): Default = 50; <br />Erodability Factor (K): Default = 0.37 <br />C Factor (C): Default = 0.5 <br />P Factor (P): Default = 1.0 <br />Geometric Information: <br />Area (sq units): Can be entered by the user or the program calculates the area of a user -selected <br />closed polyline. The user also has the option to enter the area in different units. <br />Slope, S (%): Can be entered by the user or the program calculates the slope when the user <br />selects an area from the screen. <br />Length (L): Can be entered by the user. If the user selects an area from the screen, the length is <br />not calculated since the Gross Erosion is directly calculated. <br />Topographical Factor (Ls): Will be calculated from Length (L) and the Slope (S), only when <br />these values are entered by the user directly, as against calculated by the program from the <br />screen. In the second case, the value of Ls is calculated for individual grids and not for the entire <br />area. <br />Ls = (L/72.6)^m * ((430*S^2 + 30*S + 0.43)/(6.613)) <br />where L and S are defined above and <br />Page 2.05.3(3)-17 January 2016 (TR -70) <br />