Laserfiche WebLink
VII. COST ESTIMATE <br /> Conceptual designs for all alternatives were prepared for the proposed improvements in <br /> sufficient detail to determine and document construction quantities and subsequently, a <br /> planning cost estimate. Topographic mapping at a scale of 1"=800' was used as base <br /> mapping for conceptual designs. Criteria used for preparing quantities were as follows: <br /> Channel Sections <br /> • Trapezoidal section <br /> ♦ Size using normal depth or HEC-2 <br /> • 2:1 sideslopes for the major channel improvements at the HWY 6 and UPRR <br /> ♦ 3:1 sideslopes for the main channel <br /> Drop Structures <br /> • Concrete cutoff wall for the entire width of the channel <br /> ♦ 5 feet of Type M Riprap upstream of the cutoff wall and 25 feet of Type H <br /> Riprap downstream of the cutoff wall <br /> Standard Levees (100-Year) <br /> • 10 feet top width <br /> ♦ 3:1 sideslopes <br /> ♦ 3 feet minimum of freeboard <br /> Overtop Levees (50-Year) <br /> • 10 feet top width <br /> ♦ 3:1 sideslopes <br /> ♦ Riprap slope protection <br /> ♦ No freeboard <br /> Ring Levees <br /> • 10 feet top width <br /> ♦ 3:1 sideslopes on the channel side <br /> ♦ 5:1 sideslopes on the landward side <br /> ♦ 3 feet minimum of freeboard <br /> Floodwalls <br /> ♦ 1 foot thick <br /> ♦ Footing meeting CDOT standard drawings <br /> ♦ 3 feet of cover over footings <br /> ♦ 3 feet minimum of freeboard <br /> Road Raises <br /> ♦ 24 feet wide pavement section <br /> ♦ 3:1 sideslopes <br /> ♦ Maximum 5% longitudinal slope <br /> 24 <br />