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. . . Community Resoonse to the CWCB Desie:nation and Aooroval Process The community was contacted initially by letter. In a follow up phone call a meeting was arranged with local officials to present the CWCB's proposal to designate and approve approximate floodplain information for Hugo. A meeting was conducted by CWCB staff on May 3, 1996. Local officials in attendance included the town manager. The manager was very receptive to the CWCB's designation and approval of the town's floodplain information. ENGINEERING METHODS Hvdrologic Analvsis Hydrology information for the stream with an approximate floodplain delineation on Hugo's FIRM should be estimated in accordance with the CWCB's "Guidelines for Determining 100- Year Flood Flows for Approximate Floodplains" (Guidelines). Utilization of the regression equation for Big Sandy meets the drainage area criteria set forth in the Guidelines and are valid. The equation is Q,oo = 1,564.98(A)o.s39 , where QlOO is the IOO-year peak flow in cubic feet per second, and A is the upstream (contributing) drainage area in square miles. However, the drainage area for Cemetary Creek is less than 25 square miles but larger than 0.5 square miles. Therefore, the U.S.G.S. publication entitled "Rainfall-Runoff Modeling and Preliminary Regional Flood Characteristics of Small Rural Watersheds in the Arkansas Basin in Colorado" is appropriate to use. Table 1 Estimated lOO-Year Peak Flows For Big Sandy and Cemetary Creeks at Hugo, CO Stream Location Drainage Area (sq mil IOO-Year Peak Flow in CFS Cemetary Creek at 1.6 D.A. is too small for upstream town limit regression equation Cemetary Creek at 1.8 D.A. is too small for downstream town limit regression equation Big Sandy Creek at 734.6 54,867 upstream town limit Big Sandy Creek at 775.4 56,489 downstream town limit