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CO OL COURSE Page 24 <br /> ION AND SED NT AROC"; <br /> Table 1 : C-Factor and P-Factor Values for Rainfall Erosion <br /> Control Measures (from HDI, December, 1991) . <br /> Q-Far.tQj: P-a=01: <br /> BARE SOIL 1. 00 1 .00 <br /> Packed and Smooth . . . . . . . . . . . 0 .90 <br /> Freshly Disked . . . . . . . . . . . . . l. 00 <br /> Rough Irregular Surface . . . . . . . . . 1. 00 0 .90 <br /> SEDIMENT BASIN/TRAP . . . . . . . . . . . . . 1. 0' 0 0 .50A <br /> STRAW BALE BARRIER, GRAVEL FILTER, SAND BAGS - 1.00 0 .80 <br /> SILT FENCE BARRIER . . . . . . . . . . . . . . 1. 00 0 .50 <br /> ASPHALT/CONCRETE PAVEMENT . . . . . . . . . . 0 .01 1.00 <br /> GRAVEL (1/4u To 1 1/20 ) @ 135 TONS/ACRE. - - - 0 . 05 1 .00 <br /> ESTABLISHED NATIVE GRASS . . . . . . . . . . . Fig 4 1 .00 <br /> . . <br /> SOD GRASS . . . . . . . . . . . . . . . . 0 .01 1.00 <br /> TEMPORARY VEGETATION/COVER CROP . . . . . . . 0 .45B 1 .00 <br /> 1.00 <br /> HYDRAULIC MULCH @ 2 TONS/ACRE . . . . . . . . 0 .100 <br /> SOIL SEALANT . . . . . . . . . . . . . . . . 0 .01 - 0 .60D 1 .00 <br /> EROSION CONTROL MATS/BLANKETS . . . . . . . . 0 .10 1.00 <br /> HAY OR STRAW DRY MULCH @ 2 TONS/ACRE &: ANCHORED <br /> Assumes planting of grass seed has occurred- prior to <br /> application, otherwise C-Factor = 1.00 . . . <br /> Slone M., 0 .06 1.00 <br /> 1 to 10 . . . . . . . . . . . . . . . . 0 .07 1.00 <br /> 11 to 15 . . . . . . . . . . . . . . . . <br /> 16 to 20 . . . . . . . . . . . . . . . . . 0 .11 1.00 <br /> 21 to 25 . . . . . . . . . . . . . . . . 0 .14 1.00 <br /> 25 to 33 . . . . . . . . . . . . . . . . 0 .17 1.00 <br /> > 33 . . . . . . . . . . . . . . . . 0 .20 1.00 <br /> CONTOUR FURROWED SURFACE <br /> Must be maintained throughout construction activities, <br /> otherwise P-Factor = 1.00 . Maximum length refers to down <br /> slope length. <br /> th (feet) <br /> 1.00 0 .60 <br /> 1 to 2 400 . . . . . . . . . . . 0 .50 <br /> 3 to 5 300 . . . . . . . . . . . 1-00 <br /> 6 to 8 200 . . . . . . . . . . . 1.00 0 .50 <br /> 9 to 12 120 . . . . . . . . . . . . 1 .00 0 .60 <br /> 13 to 16 80 . . . . . . . . . . . 1 -00 0 .70 <br /> 17 to 20 60 . . . . . . . . . . . 1- 00 0 .80 <br /> > 20 50 . . . . . . . . . . . 1 .00 0 .80 <br /> NOTE: Use. of other C-Factor of P-Factor values reported -in this <br /> table should be substantiated by documentation <br /> A: Should be constructed as the first step in over lot grading <br /> B: Assumes planting occurs within optimal climatic conditions <br /> C: Some limitation on use in arid and semi-arid climates <br /> D: Value used must be substantiated by documentation <br />