Washington Phase II Fish Diversion Screen Evaluations in the Yakima River Basin, 1999.
Pacific Northwest National Laboratory (PNNL) evaluated 20 Phase II screen sites in the Yakima River Basin as part of a multi-year study for the Bonneville Power Administration (BPA) on the effectiveness of fish screening devices. The sites were examined to determine if they were being effectively operated and maintained to provide fish a safe, efficient return to the Yakima River. Data were collected to determine if velocities in front of the screens and in the bypass met current National Marine Fisheries Service (NMFS) criteria to promote safe and timely fish bypass and whether bypass outfall conditions allowed fish to safely return to the river. In general, water velocity conditions at the screen sites met fish passage criteria set forth by the NMFS. Although velocities often fluctuated from one sampling location to the next, average sweep velocities typically exceeded approach velocities and increased toward the bypass. Mean approach velocities were below the NMFS criteria of < 0.4 feet per second (fps) at most sites (Table 1). Based on our observations in 1999, we believe that most facilities were efficiently protecting juvenile fish from entrainment, impingement, or migration delay. Most screens were properly sealed to prevent fish entrainment and injury, although potential problems were identified at several screen sites. Six sites (one fewer than the seven sites identified in 1998) had loose or damaged seals that might have allowed fish to be entrained (Table 1). Other sites still had spaces larger than 3/32 in. where small fish could possibly pass into the irrigation canal.
- Research Organization:
- Bonneville Power Administration, Portland, OR (US)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- 00000652
- OSTI ID:
- 786506
- Report Number(s):
- DOE/BP-00000652-4; TRN: AH200132%%272
- Resource Relation:
- Other Information: PBD: 1 Apr 2000
- Country of Publication:
- United States
- Language:
- English
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Washington Phase II Fish Diversion Screen Evaluations in the Yakima River Basin, 2000.
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