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b. Where the flow begins to concentrate in a natural drainage or a diversion ditch, a land flow condition of 8 is generally used. A landform condition of 8 is described as large gullies, diversion and low flowing streams. Please revise the SEDCAD+ u~odel to use a landflow condition of 8 in drainages and diversion ditches. c. There was a large discrepancy is the flow length and slope between the model prepared by Colowyo, what is currently in the permit and what is estimated by the Division. The Division estimated the length and slope for the flow to reach the basin outlet from the hydraulically most remote point on the watershed. The Tipton and Kalmbach model only documented the average slope of the watershed. The following differences were noted; Watershed Area Colowvo Permit DMG A 875' @ 7.S% 14.6% 2,375' @ 1S% B ],000' @ 7.S% 11% 4,000' @ 16%a C 2,000' @ 7.75% I1.6% 2,900' @ 25% D 1,000' @ 12% 8.S% 2,200' @ 1S% F 3,165' @ 24.8% 11.2% 5,600' @ 14% 2,750' @ 2% G 6,632' @ 11.8% 13% 6,000' @ 12.5% 500' @ 2% H 625' @ .8% 10.3% 6,065' @ 14% 1 1,554 @ 14.8% 15.9% 1,550' @ 37% 450' @ 2.22% J 1,304' @ 16.10% 11.3% 1,150' @ 45% 1,250' @ 1.2% K 4,880' @ 12% 19.7% 4,500' @ 16% 2,125' @ 2.82% L 1,750' @ 4.29% 21.9% 2,475' @ 23% M 1,625' @ 4% 20.2% 3,422' @ 16.8% N 1,065' @ 7.98% 19.8% 3,400' @ 16% O 625' @ 4% 12.4% 2,000' @ 16% P 375' @ 6.67% 1 ].6% 950' @ 11% Please reevaluate the length and the slope used to estimate the time of concentration in the SEDCAD+ model. S. The Division came up with some different acreage numbers than Colowyo for a few of the watersheds. For Culvert B, Colowyo used 78.05 in the model and the Division calculated roughly 87 acres. For Culvert B, Colowyo used 137.04 and the Division calculated roughly 145 acres. For Culvert P, Colowyo used .17 acres and the Division calculated .6 acres. Please reevaluate the above noted watershed acres used in the SEDCAD+ model, and change the model accordingly.