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Long HoNow Reservoir <br />Feasibility Study <br />According to the USBR, it is reasonable to assume that antecedent precipitation has <br />satisfied soil moisture deficiencies; however, WWE felt that it was appropriate to include <br />a deficit of 1 inch per foot for the LHR watershed. <br />3. Wetting Front Suction. The wetting front suction was estimated to be 12.7 inches. The <br />wetting front suction was based on a weighted average of values from Table 5-2 of the <br />Hydrologic Modeling System (HEC-HMS) Technical Reference Manual. The Soils <br />Survey for La Plata County indicates that the soils in the area of interest are primarily <br />comprised of loam, with some clay loam (to relevant depths). <br />4. Hydraulic Conductivity. The hydraulic conductivity was estimated to be 0.09 inch per <br />hour. This value represents a weighted average of minimum infiltration values.presented <br />in the Flood Hydrology Manual based on hydrologic soil groups. The Soils Survey for La <br />Plata County indicates that the soils within the tributary basin are primarily comprised of <br />Type C soils, with some Type D soils (to relevant depths). <br />5. Impervious Area. The impervious area for the watershed was estimated at 5 percent to <br />account for the limited potential for development within the basin. <br />Appendix E contains the HEC-1 input, the hydrograph for the basin, and the summary printout <br />for the model run. Table 3.4.4-1 below summarizes the results of the modeling run for each <br />element in the model. Exhibit 3.4.4-1 presents the inflow hyetograph and hydrograph for LHR, <br />and Table 3.4.4-2 gives the hourly runoff volumes. <br />TABLE 3.4.4-1 <br />Model Elements and Peak Flow Rates <br />Model Element Description Contributin Area (mi ) Peak Flow cfs <br />B1 Basin 1 43 39,568 <br />RES IDF 43 32,412 <br />991-077.120 Wright Water Engineers, Inc. Page 20 <br />April 2005 <br />