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1 Reservoir Operating Studies ' As the currentstudy it progressed, became apparent that there was a need to have the flow recommendations defined at Maybell and it was decided that the Yampa River basin ' model could be used to help define preliminary flow recommendations Maybell. This was accomplished by defining a model scenario that represented current potential demand conditions plus additional depletions that had already undergone Section 7 consultation or ' which had otherwise been reflected in the HYDROSS Environmental Baseline. The "current potential conditions with consulted depletions" model scenario was defined to correspond as closely as possible with the previous modeling work done by the Service in connection with the Stagecoach Reservoir Project (SRP) Section 7 consultation. In particular, this scenario is meant to provide the "Environmental Baseline" required for conducting preliminary Section 7 consultations for the proposed enlargement of Elkhead Reservoir. It was necessary to "re-create" the Environmental Baseline using the Yampa River basin model since the differences between the modeling approach used in the present study and the HYDROSS approach used by the Service made direct comparisons of current model results to the original HYDROSS-based Environmental Baseline difficult. Table 2-3 presents a statistical summary of flow conditions at Maybell resulting from the "current potential conditions plus consulted depletions" model scenario. Average monthly flows are presented for three exceedance levels, the 25th percentile, the 50th percentile (or median), and the 75th percentile. The 25th percentile flows are flows which are exceeded in 25 % of years, i.e., they correspond to wet year conditions; the 75th percentile flows are exceeded in 75 % of years and correspond to dry year conditions. More detailed results of this model scenario can be found in Appendix D. ' Table 2-3 Modeled Current Conditions with Consulted Depletions Flows at Maybell Ws) Month 25% exc. 50% exc. 75% exc. ' October 291 204 November 344 255 129 209 December 322 228 179 January 284 217 179 ' February 336 256 238 March 717 498 395 April 3,117 2,086 1,381 May 7,016 5,754 4,039 ' June 6,363 5,147 3,644 July 1,753 999 444 August 368 220 91 ' September 163 91 31 Preliminary Flow Recommendations at Maybell The preliminary flow recommendations at Maybell are basi cally the median flows which ' result from this "current potential conditions with consulted deple tions" model run. The preliminary flow recommendations are presented in Table 2-4. n 2-10