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原文传递 EVALUATION OF JUVENILE SALMONID BYPASS FACILITIES AND PASSAGE AT WATER DIVERSIONS ON THE LOWER UMATBLLA RIVER

题名：	EVALUATION OF JUVENILE SALMONID BYPASS FACILITIES AND PASSAGE AT WATER DIVERSIONS ON THE LOWER UMATBLLA RIVER
作者：	William A. Cameron Suzanne M. Knapp Richard W. Carmichael
关键词：	juvenile；evaluation；bypass；almon；divers；umat；matb；sage；water；fish
摘要：	Outdated juvenile and adult fish passage facilities were recently reconstructed at the five major irrigation-dams on the lower Umatilla River, Oregon to meet National Marine Fisheries Service (NMFS) design standards. Changes in design at juvenile fish bypass facilities included reduced mesh size on the rotating drum screens, larger screening area, a more oblique ' orientation of the drum screens to canal flow, improved screen seals, replacement of bypass portals with vertical slot bypass channels, and increased bypass pipe diameters. Weir-and-pool adult fish ladders and jump pools were replaced with vertical-slot ladders. From 1991-1995, we investigated injury and travel rate of juvenile fish moving through the facilities, and efficiency of screens in preventing fish entry into the canals. Water velocities in front of canal screens, at bypass channel entrances, and at ladder diffusers were measured to assess adherence to NMFS criteria and identify hydraulic patterns. Biological evaluations were conducted by releasing and recapturing marked yearling summer steelhead (Oncorhynchus mykiss ) yearling spring Chinook salmon (0. tshawytscha), and subyearling fall Chinook salmon (0. tshawytscha) in varying locations within the fish passage facilities. Most test fish passing through bypass facilities and fish ladders incurred insignificant or negligible injury {P > 0.10). Significant injury at West Extension Canal (P = 0.006) and Feed Canal (P = 0.01) bypasses was probably a result of sampling error and handling injury, respectively. Subyearling fall Chinook salmon were injured in the passage section of the east-bank fish ladder at Three Mile Falls Dam (P = 0.04) and in the auxiliary water system of. the fish ladder at Westland Dam (P = 0.05). Respective descaling and mortality rates for subyearling fall Chinook salmon were 19.2% and 3.2% at the Three Mile Falls Dam ladder, and 1.4% and 0% at the Westland Dam ladder. Midchannel diffusers probably caused most of the descaling at both sites; the slot-and-pool segment cf the passage section caused most of the mortality at Three Mile Falls Dam. Movement of subyearling fall Chinook salmon was slower near drum screens (62 m/h) than in the headworks canal (485 m/h) at Furnish Canal. Short delays were associated with the headgates and outfall at West Extension Canal and the bypass pipe at Westland Canal. Extensive delay was associated with the uppermost midchannel diffuser in the passage section of the east-bank fish ladder at Three Mile Falls Dam. Screening efficiencies of drum and vertical belt screens were greater than 99.7% and 99.4%, respectively. Impingement of test fish on the vertical belt screen at West Extension Canal was less than 0.7%. Approach velocities in front of drum screens are expected to meet criteria for smolt protection (< 0.24 m/s) and exceed criteria for fry protection (≤ 0.12 m/s) at maximum canal flow expected from March through May. Highest approach velocities were usually measured at screens near the bypass channel. Sweep to approach velocity criteria (> 2:1) was met at all sites except Maxwell Canal, where sweep velocities were low (0.08-0.16 m/s) at the screen furthest from the bypass channel. Water velocities at bypass channel entrances ranging from 0.58-0.82 m/s met criteria. Water velocity in front of the vertical belt screen at West Extension Canal met criteria when both 0.28 m'^/s-pumps were on or the pumpback bay drain pipe was 20% open. Direction and magnitude of flow approaching ladder diffuser panels was variable. In general, current designs of bypass and ladder facilities on the lower Umatilla River safely and quickly pass juvenile salmonids. However, some facility components pose passage problems for juvenile fish. Regular maintenance and proper operation of facilities, and minor modification of facility structures are recommended. Designs for adult fish ladders should include consideration of juvenile fish passage.
报告类型：	科技报告