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.~ <br />Table 4 - SEDCAD 4 Parameters: Post-minin <br /> Trapper's Trapper's basis for <br />' <br />Parameter selection selection stated on page 12 Division <br />s comment <br /> of submittal <br /> 2.75 inches in 24 hours is <br /> Produces minimum 0.5 inch historically high for Trapper's <br />Design 2.75-inches <br />of runoff that is necessary to climate, but is necessary because <br />event in 24 hours SCS TR-55 questions the accuracy <br /> maintain program accuracy. of the CN method when runoff depth <br /> is less than 0.5 inch. <br /> Trapper's selected cover, Reasonable based on reasonable <br />CN 61 soil group, hydrologic selections of cover, soil group, <br /> conditions, and CP factor hydrologic conditions, and CP factor <br /> (see below) (see following comments). <br />Pasture, grassland, Reasonable because, of the six cover <br /> descriptions in Table 2.2c of TR-55, <br />or range - <br />continuous forage None this one most accurately represents <br />for grazing the pre-mining cover on the bond <br /> release arcels. <br /> Reasonable because "Good" <br /> corresponds to greater than 75% <br />"Good" hydrologic ground cover and lightly or only <br />condition None occasionally grazed. The bond <br /> release parcels have greater than <br /> 75% cover and can be expected to be <br /> li h[l or occasionall razed. <br /> Reasonable because infiltration rate <br />}Iydrologic soil of B is O.IS-0.30 inches per hour. <br />group classification None This infiltration rate is less than the <br />„B„ post-mining infiltration rates of <br /> Trapper's soils shown in Table 4.8- <br /> 14 ofthe ermit a lication. <br />Page 5 <br />