Laserfiche WebLink
ERG CC&V Poverty Gulch Diversion Channel Sizing <br /> December 2016 <br /> Channel Outlet <br /> Because of the steep slope of the diversion channel and the expectation that flow will exit the channel in <br /> a supercritical condition, ERC deems a stilling basin necessary at the outlet of the channel to dissipate the <br /> energy from the flow before it is released to the environment. ERC sized the stilling basin using the <br /> American Society of Agricultural Engineer's "Design of Rock Chutes" program (Robinson et al. 1998) and <br /> verified the sizing using HEC-RAS.The stilling basin was sized to have a 4-foot bottom width (same as the <br /> channel bottom width) and be 15 feet long. The stilling basin outlet is shown in detail on Sheet A20 of <br /> Appendix A. <br /> Channel Inlet <br /> To prevent scouring at the inlet of the diversion channel, ERC recommends grading upstream of the <br /> channel to match the existing ground and riprapping this surface. The same size riprap as used for <br /> armoring in the diversion should be utilized for the inlet,and should also be placed on top of a non-woven <br /> geotextile fabric filter.A detail of the channel inlet is also provided on Sheet A20 of Appendix A. <br /> References <br /> Federal Highway Administration (FHWA). Design of Roadside Channels with Flexible Linings. U.S. <br /> Department of Transportation. Hydraulic Engineering Circular No. 15, 3`d Edition. September <br /> 2005. <br /> Newmont Mining Corporation (Newmont). Globe Hill Stormwoter Diversion Channel. Technical Report <br /> #86. Cripple Creek&Victor Gold Mining Company. Greenwood Village,CO. November 2016. <br /> Robinson, Rice,and Kadavy.Design of Rock Chutes.American Society of Agricultural Engineers.Vol.41(3), <br /> pp. 621-626. 1998. <br /> Steffens and Associates, Inc. Storm Water Management Plan for Mine-Life-Extension 2 (MLE 2) at the <br /> Cresson Project. Prepared for the Cripple Creek & Victor Gold Mining Company. Golden, CO. <br /> January 2012. <br /> U.S.Army Corps of Engineers (USACE). HEC-HMS.Version 4.1. [Software]. 2015. <br /> U.S.Army Corps of Engineers (USACE). HEC-RAS.Version 5.0.3. [Software]. 2016. <br /> Appendices <br /> AppendixA—Diversion Channel Plan and Profile <br /> 4 <br />