Laserfiche WebLink
<br />aLTERNATIVE 3 - SIDE CHANNEL SPILLWAY <br /> <br />This alternative would include a spillw"y located in the left: abutment <br /> <br />founded entirely in the Denver Formation. A typical plan, section, and profiles <br /> <br />are shown on plates 33 and 34. The concret:e ogee weir, walls, slabs, and <br /> <br />anchorage are similar to that of altelCnative 2. Flows into the spillway would <br /> <br />be directed through the embankment in Co a trough where the water would then be <br /> <br />redirected 90 degrees through a chute so that flood flows would run adjacent to <br /> <br /> <br />the embankment toe toward Cherry Creel<. The 1::rough and "hute were designed so <br /> <br />that the maximum submergence of the ogee section would b" less than l:wo-thirds <br /> <br />of the design head in accordance with informa1:ion contained in EM 1110-2-1603. <br /> <br /> <br />A two-lane blCidge would be required over t:h" spillway for county road traffic, <br /> <br />This spillway configuration is significantly more expensive than the other <br /> <br />spillway plans considered, however. only a minimum amount of land would be <br /> <br /> <br />required in fee title for construction operation and maintenance purposes and no <br /> <br />land would be required for flowageeaGements. <br /> <br />Costs were developed for only one option for this alternative. As shown on <br /> <br />table 14, option 3b would cost about $11. 7 million, <br /> <br />AIJERNATIVE 4 - LEFT ABUTMENT CHANNEL SPILLWAy <br /> <br /> <br />This alcernative would include a Hned spillway channel located as far into <br /> <br /> <br />the left abucment as possible. This alternative is shown on pl.ate 31. At this <br /> <br />location, the spillway is founded enti"ely on the Denver Formation. Flows would <br /> <br /> <br />be channeled through the embankment and would be directed downstream to a natural <br /> <br /> <br />gully and then into Cherry Creek, A typical plan, 'section, and profilE' is shown <br /> <br /> <br />on plate 35. The spillway rating eui'Ve "'as determined by computing critical <br /> <br />depth for various discharges and widths and multiplying by a factor of 1,56 which <br /> <br /> <br />accounts for energy head at the critical depth 5e"tion and any losses caused by <br /> <br /> <br />friction, contraction, and abutments. <br /> <br />As with the previously discussed alternat.ives, this alternative would <br /> <br /> <br />require a bridge over the spillway for county road traffic, <br /> <br />51 <br />