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CONCLUSIONS AND RECOMMENDATIONS This study documented fish escapement from Elkhead Reservoir during runoff in 2003 and 2004. The capture techniques quantified the escapement from the spillway and reservoir outlet. The study objectives were: 1) quantify escapement of fishes from Elkhead Reservoir by species and size during spring runoff; 2) recommend the design and operational criteria for screening reservoir outflows that would be most effective for minimizing escapement; and 3) evaluate escapement rates of nonnative gamefish relocated from the Yampa River to the reservoir. The following conclusions can be made from the study (Note: the controlled outlet was not operated during the study and therefore conclusions are based on escapement from the reservoir spillway): ^ The data collected does quantify escapement by species and size. ^ The majority of the escapement was small bluegill and black crappie. ^ The highest numbers of fish were captured during the highest runoff period in both years. ^ Low numbers of adult fish were captured in both years. ^ No tagged fish from the relocation were captured. ^ Rates of smallmouth bass escapement, including stocked bass, were low relative to reservoir abundance. The following recommendations are made to minimize escapement from the reservoir. These recommendations are made with the assumption that the proposed reservoir enlargement and dam reconstruction will occur. The draft results from this project were presented to the Upper Colorado River Basin Biology Committee in early 2004. The discussions at that meeting and final results of the study were used to develop the following recommendations: • All controlled outlets (gated) from the enlarged reservoir should be screened using a conventional fixed metal screen. • The screen opening should exclude adult and juvenile size classes for smallmouth bass. • The screen should be designed for exclusion with no fish bypass incorporated into the design. • Cleaning mechanisms as needed should be installed on the screens. • The primary release mechanism from the reservoir should be the controlled outlet structure and secondarily the uncontrolled spillway. • The controlled outlets should be operated at the maximum capacity practicable during runoff to minimize the magnitude and duration of spill from the reservoir. • If possible, and in coordination with annual reservoir operations, a drawdown of the reservoir to further curtail spill should be considered. • Reservoir escapement monitoring post-Elkhead enlargement should be conducted to evaluate operational releases. • Adaptive management should used after reservoir reconstruction to adjust the above recommendations as needed to minimize escapement. FINAL REPORT -Elkhead Reservoir Escapement, Project No.: 118 Page 19 Miller Ecological Consultants, Inc. May 20, 2005