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<br />19 <br />To illustrate the impacts to Reach One when the Action(ALL) ruleset was triggered to <br />achieve the 18,600 cfs objective, Figure 14 shows a sample spring hydrograph in Reach One for <br />all three model runs, The data in this figure is from trace 37 in year 2015 from May through <br />July, The peak release that achieved all flow objectives except the 18,600 cfs objective had a <br />magnitude of 4600 cfs and a duration of about 16 days, Because the Yampa River triggered the <br />Action(ALL) ruleset to attempt to achieve the 18,600 cfs objective, the peak release magnitude <br />was reset by the Action(ALL) ruleset from 4600 cfs to 8600 cfs and the duration was decreased <br />to 14 days. This caused a significant bypass to occur in a year when achieving all other flow <br />objectives would not have required a bypass release, The historic year of this hydrology was <br />1970, For reference, the No Action model results and the historic spring releases that actually <br />occurred at Flaming Gorge Dam in 1970 are included on the figure, <br /> <br /> <br />Reach One <br /> <br />10000 <br /> <br />8000 <br /> <br />~ 6000 <br />~ <br />~ <br />~ <br />0 <br />Ii: <br /> 4000 <br /> <br />2000 <br /> <br />~y-Ol <br /> <br />Example Flow Hydrograph - Reach 1 <br /> <br />Historical Year 1970, Trace 37 Year 2015 <br /> <br />{)- No Action <br />-H- Historical (1970) <br />-+ All-I <br />-All <br /> <br /> <br />Jon-Ol <br /> <br />Aug-Ol <br /> <br />Ju1-01 <br /> <br />Date <br /> <br />Figure 15 shows the corresponding flows that occurred in Reach Two as a result of the <br />release hydrographs illustrated in Figure 14, Figure 15 shows that although the Action(ALL-I) <br />model run did not achieve the 18,600 cfs objective, that 18,600 cfs was sustained for 11 days in <br />Reach Two during this year, The Yampa River flows decrease very rapidly from the peak, <br />Extending the duration of the 4600 cfs peak release would not have sustained flows in Reach <br />Two above 18,600 cfs for three additional days, <br />