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<br />Colorado Water Conservation Board <br />Endangered Fish Recovery Instream Flow Appropriation <br /> <br />Y AMPA RIVER AT MA YBELL <br /> <br />Draft September 21.1995 <br /> <br />ALTERNATIVE ll: Recovery Instream Flow Administered on a 10-year Running Total <br />or Average <br /> <br />Assumptions: <br /> <br />la. The U.S. Fish & Wildlife Service (Service) has made flow recommendations for <br />dry (80% exceedance), average (50% exceedance), and wet (20% exceedance) <br />years. The Board will appropriate the wet year recommendations less the first <br />level of the compact development allowance distributed on either a monthly or <br />daily basis for the August through March time frame (Table 1 a). For example, the <br />wet year recommendation for October is 335 cfs. The first level of compact <br />development allowance for October is 63 cfs. Therefore, the recovery instream <br />flow appropriation would be 272 cfs (335 cfs - 63 cfs). <br /> <br />lb. During the runoff months of April through July, the Service wants to allow no <br />more than the current Section 7 baseline level of depletions. Staff has assumed <br />this to mean all remaining flows, and suggests appropriating the 10% exceedance <br />level flows as defmed by the study referenced in "Assumption 2." <br /> <br />2. Water is physically available for the Service's flow recommendations as per the <br />Colorado River Basin Physical Water Availability Study conducted by the <br />Colorado Water Conservation Board (Board) staff which was based largely on <br />work done for the Board by Leonard Rice Consulting Water Engineers. The study <br />period utilized in these reports runs from 1970 - 1992. <br /> <br />3. Legal water availability was derived from preliminary information developed by <br />the Ad Hoc Endangered Fish Flow and Colorado River Compact Water <br />Development Workgroup (Workgroup) as follows: <br /> <br />Present Level of Development <br />Workgroup Projection of Future Development <br />(Lower Limit) <br />Lower Limit of Total Consumption <br /> <br />= 112,800 af <br /> <br />= 51.772 af <br />= 164,572 af <br /> <br />Additional Amount Allowed to meet <br />Colorado's full Compact Development <br />Upper Limit of Total Consumption <br /> <br />164,572 af <br />= 173.491 af <br />= 338,013 af <br /> <br />4. At least 10 years of gage record are available at the Maybell gage. Using a 10- <br /> <br />II - 1 <br />