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The following information is provided to assist the CWCB in making its findings and <br />recommendation: <br />Physical Water Availability An investigation was performed under my supervision to <br />evaluate the frequency at which water would be physically available to the claimed 100 cfs <br />(Level One) and 600 cfs (Level Two) flow rates requested by Silverthorne. To estimate physical <br />water availability, daily outflow measurements from Denver Water's Dillon Reservoir <br />Accounting sheets were analyzed for the period 1987 through 2004. The flows were increased <br />by the amount of water in Straight Creek using the USGS gage data for Straight Creek below <br />Laskey Gulch (Gage No. 09051050). This study period was selected because data for the Laskey <br />Gulch gage on Straight Creek was not available prior to Octoberl, 1986. This is the same period <br />of record used by Silverthorne. This calculation provided an estimate of the "total flow" of <br />water at the location of the proposed whitewater course. To estimate the natural flow at this <br />location, the total flow was reduced by the amount of water released from Denver Water's <br />authorized storage accounts at Dillon Reservoir to the Blue River. <br />DWD Exhibit 9 is a graph that summarizes the results of this analysis of the total flow for <br />Level One Flows (100cfs). DWD Exhibit 11 is a graph that summarizes the results of the <br />natural flow for Level One Flows. The graphs depict the percent of time, by day, there is <br />physical or natural flow to meet the amounts of Level One Flows requested by Silverthorne <br />throughout the 1987-2004 study period. DWD Exhibits 13, 15, and 17 are graphs that summarize <br />the results of this analysis for Level Two Flows (600 cfs). The graphs depict the percent of time <br />that the average natural daily flows during the four-day Memorial Day weekend; July 3, 4 and 5; <br />and the four-day Labor Day weekend were sufficient to meet the Level Two Flows (600 cfs) <br />throughout the 1987-2004 study period. DWD Exhibits 9 and 11, as well as DWD Exhibits 13, <br />15, and 17 demonstrate that there is a significant percent of time that the amount claimed by <br />Silverthorne is not physically available. <br />Le2al Water Availabilitv Notwithstanding the physical supply available to the RICD, <br />with an appropriation date of December 31, 2004, there are very few instances in which <br />unappropriated water would be available for the Blue River Whitewater Course water right <br />claimed by Silverthorne. This is a result of effectively continuous calls for water from either <br />Green Mountain Reservoir's 1935 storage and power right located downstream on the Blue <br />River, or from the mainstem of the Colorado River for Xcel Energy's Shoshone Power Plant or <br />from priorities that divert in the vicinity of Cameo. Thus this water right will be out-of-priority <br />and cannot demand water under this condition. <br />The RICD could imuair the maximum utilization of the water of the State without <br />annropriate terms and conditions. For the reasons set forth below, there are probable future <br />changes, transfers, or exchanges of water rights from points of diversion downstream of the <br />reach that Denver Water may need to file to fully utilize the amount of water diverted or stored <br />by Denver Water at Dillon Reservoir or the Roberts Tunnel under the Blue River Decree; or by <br />reason of Green Mountain Reservoir uncertainties. <br />Potential Impacts to the Blue River Decree. Denver Water is permitted under <br />the Blue River Decree to withhold Blue River water in its upstream junior Dillon <br />2