Laserfiche WebLink
<br />U4JJ <br /> <br />Platte River. Downstream water requirements could in part be satisfied by recovery <br />of the seepage. <br />Consideration will be given to using soil cement in lieu of riprap for upstream <br />slope protection during final design stage if suitable borrow material is available. The <br />amount of soil cement material required would be approximately the same as riprap. <br />A gated concrete service spillway, an auxiliary uncontrolled earth channel spill- <br />way with concrete sill, and the river outlet works would be located on the north side of <br />the dam. The river outlet works would be capable of discharging 3900 cubic feet per <br />second with the reservoir water surface at the maximum conservation elevation of 4399 <br />feet. Should the design flood occur, which is a remote possibility, the joint-use and <br />exclusive flood control capacities would be filled and surcharge in the reservoir above <br />the maximum storage level would reach 636,000 acre-feet. At maximum surcharge <br />level the combined service and auxiliary spillways will be designed to discharge a total <br />of 234,490 cubic feet per second. Space allocation in the reservoir and area-capacity <br />data including 50 and 100 year sediment conditions are shown on Figure 4. The inflow <br />design flood is estimated to have a peak discharge of 497,100 cubic feet per second and <br />a 10 day volume of 2,030,000 acre-feet. <br />The €.'<:isting diversion works for the Fort Morgan Canal and a portion of the can- <br />al would be inundated by the Narrows Reservoir. The Fort Morgan Reservoir and Irri- <br />gation Company, owner of the canal, holds a direct flow right of 323 cubic feet per sec- <br />ond with a priority date of October 18, 1882. An outlet for the Fort Morgan Canal <br />would be located near the right abutment of the dam to satisfy the water right entitle- <br />ment of the company and deliver any project water which the company might obtain from <br />the reservoir through the Lower South Platte Water Conservancy District. The capacity <br />would be 350 cubic feet per second. <br />Construction of Narrows Dam will require approximately 3.7 million cubic yards <br />of pervious and 5.9 million cubic yards of impervious borrow material. The railroad <br />relocation would require an additional!. 6 million cubic yards of borrow. Borrow quan- <br />tities are about 15 percent greater than the embankment quantities to allow for shrink- <br />age during compaction. <br /> <br />3. <br />