Laserfiche WebLink
TRAPPER MINE <br />SEDIMENT LOAD DEMONSTRATION <br />BLOCK D&F PITS RSA&B 02-04 POST-MINING <br />• <br />Area <br />204.9 acres <br />Curve Number <br />Hydrologic Soil Group: <br />Cover Type: <br />Hydrologic Condition: <br />CN (AMC II): <br />CN (AMC III): <br />Erodibility Factor <br />K: <br />B (Permit C-81-010, Appendix Q, Section XII) <br />Pasture, Grassland, or Range <br />Good <br />61 (SEDCAD 4 CN table - Other Agricultural Lands) <br />78.8 (Barfield, Warner, Haan p. 84) <br />0.25 (Permit No. C-81-010, Appendix Q, Section XIII, Table E-4) <br />Control Factor <br />• <br />• <br />Type and Height of Canopy: None <br />Canopy Cover: None <br />Percent Ground Cover: 78.6% (Trapper Mine Phase II Bond Release App., Table 1.2-1) <br />CP: 0.015 (SEDCAD 4 table for Permanent Pasture, Rangeland) <br />Roughness Modifier: 0.65 (Contour farming operations, effective herbaceous cover, <br /> contour ditches, livestock water tanks) <br />Modified CP: 0.010 <br />Average Slope and Slope Length <br />( D pit range sites A&B previously determined under SL-1) <br />( F pit range sites A&B previously determined under SL-6) <br />Site Length (ft) Slope <br />D Pit RSA 371 13.4 <br />D Pit RSB 483 15.3 <br />F Pit RSA&B 537 19.6 <br />Overall Average 464 16.1 <br />Time of Concentration <br />Land Use Category <br />Slope <br />Length (ft) <br />Tc (hrs) <br />SCADINPS2.xIs, D&F RSAB <br />1 Forest with heavy ground litter (overland flow) <br />16.1% <br />464 <br />0.127 <br />0911812009