Laserfiche WebLink
<br /> <br />" <br /> <br />Agenda Item 27 - Coordinated Facilities <br />May 19-20, 2003 Board Meeting <br />Page 6 of 12 <br /> <br />Green Mountain Reservoir storage for making the 20,000 acre-feet release from CROP bypasses, . <br />reduced Grand Valley Project demands, Palisade Pipeline bypass flows and the Shoshone Power <br />Plant maintenance schedule. Including CROP bypasses/releases, however, would not always leave <br />sufficient release capacity through the Green Mountain Reservoir turbines to make the 1,000 cfs <br />CFOPS release during the I O-day peak flow. This lack of sufficient release capacity at Green <br />Mountain Reservoir would necessitate allocating responsibility for making a portion of the 20,000 <br />acre-feet CFOPS release to other reservoirs, The opportunity for Green Mountain Reservoir to <br />function as an insurance pool in these situations and payback the other reservoirs could also be <br />considered. <br /> <br />6. An analysis was made of the effect on Colorado River flows at the head of the IS-Mile Reach to <br />determine if making the 20,000 acre-feet release generally during June would reduce flows during <br />other months. Results of this analysis indicate that the maximum average monthly reduction occurred <br />during July and reduced flows in that month by 1,048 acre-feet (295,601 acre-feet to 294,553 acre- <br />feet), <br /> <br />7, <br /> <br />Throughout the investigation, it was noticed that the exchanges and substitutions among Dillon, <br />Granby and Williams Fork reservoirs using: the CI data set in StateMod differed from the simulations <br />bv Denver Water using their dailv P ACSM model. ?;ere Bet being modelea eerreetl)" BY StateMl3l1 alla <br />the CI Data Set. In order to try and correct this problem, the CWCB modified StateMod and a fifth <br />revision was made to the CI Data Set. A comparison of the base runs with the CI Data Set (Fourth <br />Revision) and the Modified StateMod and CI Data Set (Fifth Revision) was made to determine if <br />these changes were sufficient to necessitate redoing the previous work with the Modified StateMod <br />and CI Data Set (Fifth Revision). A comparison of these two base runs indicated that a difference <br />remained. the major significant differeBce which was increased storage in Dillon Reservoir and <br />decreased storage in Williams Fork Reservoir. In order to further check the need for rerunning <br />previous simulation runs with the Modified StateMod and CI Data Set (Fifth Revision), simulation <br />runs for two alternatives were made: (I) Ckeefl) Green Mountain Reservoir making the 20,000 acre- <br />feet release and replacing this release using its refill priority and (2t-4e) the "Coordinated Reservoir <br />Augmentation Project" 8hlll'e the Pain .^'Iternatiye with responsibility for making the 20,000 acre-feet <br />release divided equally among Granby, Green Mountain and Williams Fork Reservoirs. Results of <br />these additional simulation runs did not differ significantly enough to change original conclusions <br />presented in the Technical Memoranda concerning these alternatives. However, comparing <br />simulations by Denver Water using its daily P ACSM model with skewea that StateMod showed <br />differences in was still Bet aaeEjuately accounting for exchanges and substitutions into and out of <br />Dillon, Williams Fork and Wolford Mountain reservoirs. These differences would significantly <br />overstate€! the availability of water for release from these reservoirs for meeting the 20,000 acre-foot <br />goal. Rather than continue to investigate and debate the need for further refinements to the models. <br />Hewevor, it was determined that time would be better spent working on what could be done to meet <br />the 20,000 acre-foot goal" instcaa ef malciflg more meael imprw;eHleflls to and runs ?;ilb SlateMod. <br /> <br />. <br /> <br />Feasibility of Expanded Crop Alternatives <br /> <br />From an engineering and economic perspective, the following alternatives probably could supply the 20,000 <br />acre-feet to the IS-Mile Reach when required during the study period, at reasonable costs: <br /> <br />. Alternative la: Green Mountain Reservoir reduced winter power operations <br /> <br />. <br /> <br />Alternative la: Green Mountain Reservoir conjunctive pool operations <br /> <br /> <br />Alternative la: Preemptive release and water carried over in Green Mountain Reservoir <br /> <br />. <br /> <br />. <br /> <br />Flood Protection. Water Project Planning and Finance. Stream and Lake Protection <br />Water Supply Protection. Conservation Planning <br />