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Colorado Water Conservation Board Members <br />Mr. Thomas Browning, P.E., CWCB <br />Review of Lacy Report for Chaffee County Whitewater RICD <br />May 10, 2005 <br />Page 6 of 9 <br />The report doesn't present data, documentation or address these issues and questions. These <br />issues and needs are commonly addressed by whitewater design, planning, and engineering. <br />5. Design drawings and specifications are not provided including an overall plan with access and <br />parking, general existing and design bed and bank topography, detailed whitewater facility design <br />topography and features, plan and profiles drawings, sections across the waterway and features, <br />general and specific details, flow patterns and water surface profiles, The plans should designate <br />location of various materials. No construction drawings were provided for the whitewater facilities, <br />river stabilization, or hydraulic controls. The sketches in the report have no elevations, <br />dimensions, specificity necessary for construction, or analytical proof of their performance. <br />The reference to "Roman Arches" is a misleading, as the primary loads applied to an arch are <br />typically in the vertical plane with uniform loads above the arch. In the proposal there are not rigid <br />abutments to pick up the load, and the load that is faced by a river grade control structure is <br />primarily due to uplift, hydraulic forces such as drag and impact, and scour of the bed which <br />destabilizes the structure by undermining. All of these loads are to the side of the arch, which <br />cannot be resisted by arching action. Stability of the grouted boulder structure is achieved by the <br />buoyant mass overcoming the uplift and various drag forces, and having sufficient protection <br />against scour and undercutting. Further, there are numerous grade control and whitewater <br />features which have no "arch ". Many successful hydraulic structures are constructed of grouted <br />boulders with cutoff, seepage, and erosion control measures. Where are the calculations for the <br />loads, forces, and stability? <br />6. Analysis and design refinement of the facilities should be provided. At minimum, a one <br />dimensional, mixed flow (sub - critical and supercritical) hydraulic model should have been <br />provided, with adaptations to account for water flow patterns. In simple terms, exact water surface <br />profiles, velocity characteristics, and flow patterns should be determined. <br />C13 <br />12596 WEST BAYAUD AVENUE, SUITE 200, LAKEWOOD, CO 80228 <br />303.458.5550 FAX 303.480,9766 <br />