Upstream Passage. The Technical Subcommittee completed a preliminary evaluation of alternatives for upstream passage, their chances for success, and the potential implications for other resources associated with each alternative (Xxxxxxx et al. 1999). Two engineering efforts were conducted to refine upstream passage alternatives. Existing fish facilities at the Project were investigated to determine if they could be reactivated in either an experimental or long-term program, and concepts for potential new facilities were developed (Duke Engineering & Services 1999a). In addition, existing trap-and-haul and ladder facilities at other dams in the Northwest were surveyed to determine common features of successful and unsuccessful programs (Duke Engineering & Services 1999b). Some improvements to existing upstream passage facilities have already been implemented. An accumulation pool was constructed at the Xxxxxx Fish Trap in 2000. Initially this pool will allow more frequent processing of fish for transfer to the Round Butte Hatchery and the timely return of wild adults to the Deschutes River. Ultimately this pool will allow for the efficient sorting of adult fish destined for passage upstream of the Project from those to be transferred to the hatchery. In addition, a finger xxxx was added to the pool on the east bank of the river below the Round Butte powerhouse to prevent larger fish from leaving the pool after they enter, which allows for more accurate counting of adult bull trout attempting to migrate upstream from Lake Simtustus. The xxxx has been in place and the pool has been monitored to determine numbers of unmarked bull trout, previous years’ tagged bull trout, and the current year’s tagged bull trout. The bull trout population in Lake Simtustus is estimated from these counts.
