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an average of 15,201 acre -feet annually, spills from Granby Reservoir increased by an average <br />of 13,022 acre -feet annually, and the target flow shortages are reduced by an average of 3,601 <br />acre -feet annually. In Run C, when the C -BT Project increases diversions of in- priority east <br />' slope water and delivers only charge water, the Adams Tunnel diversions are reduced by an <br />average of 50,623 acre -feet annually, spills from Granby Reservoir are increased by an average <br />of 47,784 acre -feet annually, and target flow shortages are reduced by an average of 13,349 <br />acre -feet annually. <br />' The Coordinated Facilities Operations Study ( CFOPS) is a requirement of the 15 -Mile <br />Reach Programmatic Biological Opinion. The goal of CFOPS is to enhance spring peak flows in <br />' the 15 -Mile Reach by an average of 20,000 acre -feet in all but extremely dry or wet years. The <br />15 -Mile Reach Programmatic Biological Opinion requires this enhancement when the peak flow <br />in the year is between 12,900 and 26,600 cfs. Historically, the peak flows are 12,900 cfs or less <br />' in approximately 20 percent of the years, and the peak flows are 26,600 cfs or more in <br />approximately 25 percent of the years. Inspection of the records for the flow in the Colorado <br />' River at Cameo showed that the peak flows in 1985, 1986, 1991, 1993, and 1996 -98 were <br />within this middle range. These were years, therefore, when the enhancement of spring peak <br />flows would have been called for by the Programmatic Biological Opinion. As shown at the <br />' bottom of Table 13, the spills from Granby Reservoir averaged 14,403 acre -feet in these years <br />in Run A and increased by annual averages of 18,498 acre -feet in Run B when increased <br />diversions of east slope water were made and 74,409 acre -feet in Run C when increased <br />diversions of east slope water were made and only charge water was delivered. Since these <br />spills occur during the period of spring peak flow, increased diversion of east slope water and <br />Ithe elimination of non - charge deliveries would accomplish this CFOPS goal. <br />Figure 10 graphs the monthly contents in Granby Reservoirs in Runs A, B, and C. <br />Appendices E, F, and G are portions of the Granby Reservoir /15 -Mile Reach spreadsheets for <br />Runs A, B, and C, respectively. <br />CONCLUSIONS <br />1. The C -BT Project did not make full use of its Big Thompson River water source during <br />1983 -98. Our analysis indicated that an average of 21,862 acre -feet annually could have <br />been diverted during this period. An average of 18,331 acre -feet of this water was <br />available in May and June. Divertible water occurred in every year of the period except <br />the 1989 and 1992 dry years and amounted to almost 93,000 acre -feet in 1983. Our <br />' analysis also indicated that an average of not more than 6,710 acre -feet annually or less <br />than one -third of the total available was actually diverted. <br />' 2. The full utilization of the Big Thompson River source could have reduced the Adams <br />Tunnel diversions that were necessary to supply the historical project demands by an <br />average of approximately 15,200 acre -feet annually. These reduced Adams Tunnel <br />diversions would have increased the spills from Granby Reservoir by an average of <br />1 17 <br />