Laserfiche WebLink
<br />Platte Valley Irrigation Company <br />November 13-15, 2006 <br /> <br />Agenda Item 10e <br /> <br />is apparent for some storage within the system to allow for more efficient operation of the ditch <br />and to control the loss of water in the system. Based on their needs, PVIC decided this option <br />was not valid and did nothing to ensure the continued efficient operation and management of <br />their system, given the current and future demands on water in the State. <br /> <br />Alternative 2, Use an Existing Reservoir to act as an Equalizer ~ This alternative considered <br />utilizing an existing reservoir as an equalizer for their system. However, there are no suitable <br />existing reservoirs near their system that would be effective as an equalizer for the Evans NO.2 <br />Ditch. <br /> <br />Alternative 3, Construct Platte Valley Reservoir No. 1 - This option considers construction of <br />a reservoir with 431 acre-feet of storage capacity to provide storage and to act as an equalizer <br />for the system. The dam embankment will be 14 feet high, constructed with 10:1 upstream <br />slopes in lieu of providing upstream slope protection, and the downstream slope at 3:1. The <br />reservoir bottom will be lined using clay from the excavation as necessary to prevent <br />groundwater intrusion. The surface area will be 43 acres at the high water line. <br /> <br />Alternative 4, Construct an Enlarged Platte Valley Reservoir No. 1 - This option considered <br />construction of a 531 acre-foot reservoir to provide storage and to act as an equalizer for the <br />system. Alternative 4 is similar to Alternative 3 in all respects except the dam embankment <br />upstream slope will be reduced to a 3: 1 and riprap slope protection utilized on the upstream <br />face. The additional reservoir capacity is due to added volume with the reduction in <br />embankment volume and additional excavation area available due to the smaller embankment. <br /> <br />Selected Alternative 3, Construct Platte Valley Reservoir No.. 1 - This option has been <br />chosen by PVIC, based on the cost and.the ability to store in excess of the 300 acre-foot <br />decree they have obtained for the reservoir. The cost of this alternative is less than the current <br />value of CBT or other water that may be available on the market. There are no major <br />impediments, other than the cost, and this alternative has a high probability of success and can <br />be accomplished by local contractors experienced in dam construction. Construction <br />components of the reservoir/canal project are: <br />1. A 431 acre-foot reservoir by excavation of the site and placement of a 14 foot <br />high dam embankment. <br />2. Use of 10: 1 upstream slopes in lieu of upstream slope protection. The <br />downstream slope will be at a 3:1, and the reservoir bottom will be clay lined. <br />3. An outlet works consisting of an inlet structure, 48 inch reinforced concrete outlet <br />conduit, and upstream control gate. The outlet will be configured to act as the <br />principal spillway for the reservoir. <br />4. A control structure which will control the supply in the ditch and filling the <br />reservoir from the ditch. <br />5. Relocation of the existing section of ditch from the split of the Platte Valley Canal <br />and Evans Ditch NO.2 and the new reservoir. The relocation is necessary due to <br />the location of the reservoir and will allow filling in the exiting ditch below the <br />bifurcation with spoil from the required excavation. <br />6. Modification of the existing bifurcation structure at the split for the Platte Valley <br />Canal and Evans Ditch No.2. This is necessary due to the relocation of the ditch <br />and also to provide adequate control of the flow to the Platte Valley Canal for <br />deliveries to FRICO. <br />7. Construction of three (3) new Parshall Flumes in various reaches of the ditch, <br />as directed by the Water Court. <br /> <br />40f7 <br />