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5 Hydrology and Hydraulics <br />The hydrology of Monument Dam was not evaluated as part of this project. Hydrologic studies are <br />required for assessing spillway capacity and conditions. Because the proposed modifications at <br />Monument Dam do not include any modification of the spillway, a hydrologic study was not <br />performed. This is reflected in the letter obtained from the State of Colorado Division of Water <br />Resources included in Appendix B. <br />The hydraulic design relating to the intake structure and outlet works are described in the following <br />sections. <br />5.1 Intake Structure Design <br />The intake structure system consists of the following elements: <br />• Intake structure <br />• Cast iron slide gate assembly <br />• Operator's platform (at the crest of the dam) <br />• Manual operator <br />5.1.1 Intake Structure <br />The intake structure is a reinforced concrete cylinder with a rectangular spread footing. The cylinder <br />has a 6-foot inside diameter with 12-inch thick reinforced concrete walls designed for approximately <br />50 feet of water pressure and possible uplift force. The footing is a 10-foot reinforced concrete <br />square that is 12 inches thick. The existing 12-inch diameter cast iron pipe (CIP) will be connected <br />to the structure using acast-in-place wall sleeve and short length of 12-inch diameter ductile iron <br />pipe. A mechanical joint sleeve will be used to join the new pipe and existing pipe. <br />The cast iron slide gate will be mounted on a flanged pipe section inside the structure. The pipe <br />section will be fabricated so that the slide gate mounting flange is angled to match the side slope of <br />the reservoir. This angled installation will allow the slide gate to be operated with a standard rising <br />' stem configuration. The base of the structure will be filled with concrete to the base of the slide gate <br />mounting flange to provide stability for the slide gate and to allow the structure to be completely <br />drained. <br />The top of the intake structure is covered with a trashrack fabricated from 1-inch diameter steel bars <br />' and anchored on the top of the cylinder. The trashrack's convex shape provides significantly more <br />open area and accommodates more blockage without restricting flow when compared to a flat inlet <br />P:\Mpls\06 CO\26\0626067\WorkFiles\DesignReport\FINAL\DesignReportFINAL.doc ~ <br />