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Table 1Sub-Watershed Quantities <br /> <br />Sub-Watershed Sub-Outlet Area Avera e Slo e <br />[No.] [Station) [acre] [%] <br />1-1 166+50 1]1.4 20.97 <br />1-2 166+50 224.0 12.33 <br />2-1 149+35 56.1 24.35 <br />2-1 149+35 50.4 21.83 <br />4-1 145+10 49.1 28.90 <br />5-1 142+15 21.0 30.76 <br />6-1 132+40 24.7 34.03 <br />6-2 132+40 8.4 15.06 <br />8-1 128+27 110.4 23.83 <br />9-1 124+05 14.2. 32.26 <br />10-1 122+IS 8.3 31.59 <br />13-1 119+10 84.6 28.26 <br />15-1 110+80 36.2 30.90 <br />17-1 105+00 21.3 37.60 <br />18-1 95+80 31.0 17.44 <br />19-1 95+00 48.2 28.14 <br />19-2 95+00 60.6 27.54 <br />20-] 95+00 32.0 31.16 <br />21-1 84+10 26.6 35.76 <br />21-2 84+10 14.7 40.06 <br />• Flood Routine Parameter <br />• <br />The flood routing chazacteristics obtained based on the drainage system networking is tabulated <br />in Table 2. <br />Muskingum routing is used to route storm water from an up-gradient to adown-gradient location. <br />The routing parameters were determined by selecting category 8 (large gullies, diversions and <br />tow flowing streams) included in SEDCAD 4 Routing Calculator. <br />Impact of Disturbed Areas <br />The total disturbed area, including the road and associated cut and fill areas, is 6.33 acres, <br />approximately 0.61% of the 1,033-acre watershed. Apparently, compared with the runoff from <br />the undisturbed azeas of the sub-drainage basins, the additional runoff from the road construction <br />is minimal. Also, the following factors made the hydrology design very conservative: a) the peak <br />flow prediction based on SCS type distributions will be higher than almost any actual measured <br />storm (Warner, 2004); and b} the trunk lines, cross culverts and cross drains were all designed <br />with extra capacities (i.e., if a CSP cross drain diameter from [he SEDCAD modeling was 15 <br />inches, then a 18-inch CSP would be designed at this location). Therefore, the SEDCAD model <br />did not account for the additional runoff from the disturbed areas because of the small percentage <br />of the azea compared to the total modeled watershed and the conservative design factors used in <br />the modeling. <br />Sunrise Engineering, Inc. <br />Sylvester Gulch Access Road <br />Hydrologic /Hydraulic Analyses for Roadway Drainage <br />