Laserfiche WebLink
<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />feasibility of minimizing the hazard classification of the dam, constructing low flow <br /> <br />diversion works capable of operating in sediment and!or ice laden conditions, and <br /> <br />utilizing Little Fountain Creek direct flow water rights, and providing for safe <br /> <br />passage of flood flows through the reservoir area. The concepts for the design <br /> <br />alternatives included the following: <br /> <br />. Expanding the width and lowering the crest of the existing spillway at the <br />south side of the reservoir roughly 12.5 to 14 feet. <br /> <br />. Lowering the dam and creating an overflow channel capable of passing <br />the design flood. <br /> <br />. Lowering the dam and designing the channel drop to City of Colorado <br />Springs! EI Paso County's urban drainage and flood control specifications <br />capable of passing the design flood <br /> <br />. Completely breaching the dam and constructing an overflow channel <br />capable of passing the design flood. <br /> <br />The general modification concept is to lower the spillway sufficiently to <br />reduce the dam size to a minor Size or smaller dam (less than 20 feet deep water <br />storage), and with the same modification reduce the water storage volume <br />sufficiently to change the potential hazard classification to Hazard Class 2, 3 or 4, <br />eliminating the potential for loss of human life should dam failure occur. With this <br />reduced size and hazard classification, the Office of the State Engineer would <br />require the dam be designed to safely pass the 1 OO-year flood event. <br /> <br />Information for the project was gathered from various sources. A lake <br />bottom (storage capacity) survey, reconnaissance geotechnical investigation, and <br />general site reconnaissance were conducted. The existing site information, <br />primarily consisting of Wheeler's previous engineering studies and the original <br />construction drawings, were reviewed for geological conditions and design <br /> <br />parameters. <br /> <br />The results of the survey, geotechnical investigation, site <br /> <br />reconnaissance, and review of existing data were used along with our experience to <br />arrive at different options for reducing the jurisdictional capacity of Keeton Dam and <br />Reservoir. <br /> <br />4 <br />