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The CUHP model (UDFCD 2017) requires several items before a simulation can be run. <br /> These are: <br /> • Determination of sub-catchments <br /> • EPA SWMM Target Node (Discussed below) <br /> • Rain gage (Discussed above) <br /> • Area <br /> • Length to Centroid <br /> • Length <br /> • Slope <br /> • Percent imperviousness <br /> • Maximum Depression Storage <br /> • Horton's infiltration Parameters (based on NRCS Hydrologic Soils Group) <br /> The determination of sub-catchments including; area, length to centroid, and slope <br /> were determined from a file obtained from DDS(DDS 2017)and loaded into Autodesk <br /> Civil 3D 2017 software. Figure 5 presents visually these data points for Basins 1 and 2 <br /> (sub-catchments). Figure 6 present similar data for the rest of the sub-catchments. <br /> Basins 1 and 2 were configured based on the interference of the proposed culverts <br /> under the Alameda Avenue Reconstruct(JSC 2016). SWMM Nodes 101, 102 and 103, <br /> 104 were selected because they are the upstream and downstream end of each culvert <br /> respectively. Node 105 was selected because it is where the ultimate drainage from <br /> sub-catchment's(basin) 1 and 2 converge. Node 106 is where HMD was under the <br /> impression where General Shale would like to start the exterior drainage ditch. The <br /> accompanying sub-catchment (basin 5) is for the stretch of channel and basin that <br /> drains to the channel between nodes 105 and 106. Basin 6 (sub-catchment)drains a <br /> side channel converging with the main channel at note 107. Basin 7 (sub-catchment) is <br /> a bit unusual because it drains into the stretch of channel between nodes 107 and 108 <br /> all along the channel. It was modeled as one basin with the longest water drop path <br /> and path to centroid shown in Figure 6. Basin 8 (sub-catchment) is the toe end of the <br /> mine and is bounded by nodes 108 and 109. There is a change in slope between 109 <br /> and 110 but no drainage area. <br /> Page 1 of attachment 4 shows the input garnered from Civil 3D as discussed previously <br /> plus the rain data also discussed previously. The entire area has no imperviousness. If <br /> one looks carefully at Figures 5 and 6 one will notice that, at least on the south side of <br /> Alameda along Alameda,the runoff from Alameda is not shown contributing flow <br /> anywhere. HMD's interpretation of the constructions plans is that this runoff for this <br /> very narrow corridor is transported further west out of the influence of the area of <br /> discussion in this drainage study(JSC 2016). <br /> Higtie 5 07/30/2017 <br />